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  Subjects -> FORESTS AND FORESTRY (Total: 108 journals)
    - FORESTS AND FORESTRY (107 journals)
    - LUMBER AND WOOD (1 journals)

FORESTS AND FORESTRY (107 journals)                     

Showing 1 - 12 of 12 Journals sorted alphabetically
Acta Silvatica et Lignaria Hungarica     Open Access  
Advance in Forestry Research     Open Access   (Followers: 3)
Advances in Forestry Letters     Open Access   (Followers: 1)
Advances in Forestry Science     Open Access   (Followers: 1)
Agrociencia     Open Access   (Followers: 1)
Agroforestry Systems     Hybrid Journal   (Followers: 20)
Annals of Forest Science     Hybrid Journal   (Followers: 4)
Annals of Silvicultural Research     Open Access   (Followers: 1)
Appita Journal: Journal of the Technical Association of the Australian and New Zealand Pulp and Paper Industry     Full-text available via subscription   (Followers: 6)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 6)
Arboriculture and Urban Forestry     Free   (Followers: 7)
Australian Forest Grower     Full-text available via subscription   (Followers: 2)
Australian Forestry     Full-text available via subscription   (Followers: 2)
Balduinia     Open Access  
Banko Janakari     Open Access  
Bosque     Open Access   (Followers: 2)
Canadian Journal of Forest Research     Full-text available via subscription   (Followers: 25)
Canadian Journal of Plant Science     Full-text available via subscription   (Followers: 15)
Ciência Florestal     Open Access   (Followers: 2)
Ciencia forestal en México     Open Access  
Colombia Forestal     Open Access  
Current Forestry Reports     Hybrid Journal  
Dissertationes Forestales     Open Access  
East African Agricultural and Forestry Journal     Hybrid Journal  
European Journal of Forest Research     Hybrid Journal   (Followers: 5)
Expert Opinion on Environmental Biology     Hybrid Journal  
Floresta e Ambiente     Open Access   (Followers: 1)
Folia Forestalia Polonica     Open Access  
Forest Ecology and Management     Hybrid Journal   (Followers: 49)
Forest Pathology     Hybrid Journal   (Followers: 2)
Forest Phytophthoras     Open Access   (Followers: 2)
Forest Policy and Economics     Hybrid Journal   (Followers: 22)
Forest Research Papers     Open Access   (Followers: 3)
Forest Science     Full-text available via subscription   (Followers: 5)
Forest Science and Practice     Hybrid Journal   (Followers: 2)
Forest Science and Technology     Partially Free   (Followers: 2)
Forest Systems     Open Access   (Followers: 1)
Foresta Veracruzana     Open Access  
Forestry Chronicle     Full-text available via subscription   (Followers: 10)
Forestry Letters     Open Access  
Forestry Studies : Metsanduslikud Uurimused     Open Access  
Forestry: An International Journal of Forest Research     Hybrid Journal   (Followers: 16)
Forests     Open Access   (Followers: 3)
Forests, Trees and Livelihoods     Partially Free   (Followers: 5)
Ghana Journal of Forestry     Full-text available via subscription   (Followers: 1)
Holzforschung     Hybrid Journal  
iForest : Biogeosciences and Forestry     Open Access   (Followers: 2)
Indian Forester     Full-text available via subscription   (Followers: 3)
Indonesian Journal of Forestry Research     Open Access   (Followers: 1)
INNOTEC : Revista del Laboratorio Tecnológico del Uruguay     Open Access  
International Forestry Review     Full-text available via subscription   (Followers: 7)
International Journal of Agriculture and Forestry     Open Access   (Followers: 7)
International Journal of Forest Engineering     Hybrid Journal   (Followers: 1)
International Journal of Forest, Soil and Erosion     Open Access   (Followers: 5)
International Journal of Forestry Research     Open Access   (Followers: 4)
Irish Journal of Agricultural and Food Research     Open Access   (Followers: 1)
Journal of Agriculture, Forestry and the Social Sciences     Full-text available via subscription   (Followers: 3)
Journal of Biodiversity Management & Forestry     Hybrid Journal   (Followers: 3)
Journal of Environmental Extension     Full-text available via subscription  
Journal of Forest and Livelihood     Open Access  
Journal of Forest Economics     Hybrid Journal   (Followers: 6)
Journal of Forest Products and Industries     Open Access  
Journal of Forest Research     Hybrid Journal   (Followers: 3)
Journal of Forestry     Full-text available via subscription   (Followers: 13)
Journal of Forestry Research     Hybrid Journal   (Followers: 6)
Journal of Horticulture and Forestry     Open Access   (Followers: 6)
Journal of Natural Resources Policy Research     Hybrid Journal   (Followers: 13)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 4)
Journal of Sustainable Forestry     Hybrid Journal   (Followers: 7)
Journal of the Faculty of Forestry Istanbul University     Open Access  
Journal of Tropical Forestry and Environment     Open Access   (Followers: 1)
Journal of Wood Chemistry and Technology     Hybrid Journal   (Followers: 7)
Journal of Wood Science     Hybrid Journal   (Followers: 4)
Jurnal Ilmu Kehutanan     Open Access  
Jurnal Manajemen Hutan Tropika     Open Access   (Followers: 1)
Jurnal Penelitian Kehutanan Wallacea     Open Access  
La Calera     Open Access  
Landscapes     Hybrid Journal   (Followers: 19)
Lesnícky časopis     Open Access  
Maderas. Ciencia y tecnología     Open Access   (Followers: 1)
Mathematical and Computational Forestry & Natural-Resource Sciences     Free  
Natural Areas Journal     Full-text available via subscription   (Followers: 12)
New Forests     Hybrid Journal   (Followers: 2)
New Zealand Journal of Forestry Science     Open Access   (Followers: 1)
Open Journal of Forestry     Open Access   (Followers: 1)
Plant Science Bulletin     Free   (Followers: 9)
Quebracho. Revista de Ciencias Forestales     Open Access  
Research Journal of Forestry     Open Access   (Followers: 4)
Revista Árvore     Open Access   (Followers: 1)
Revista Chapingo. Serie Ciencias Forestales y del Ambiente     Open Access  
Revista de Agricultura Neotropical     Open Access  
Revista Ecologia e Nutrição Florestal - ENFLO     Open Access  
Revista Verde de Agroecologia e Desenvolvimento Sustentável     Open Access   (Followers: 2)
Revue forestière française     Full-text available via subscription   (Followers: 3)
Rural Sustainability Research     Open Access   (Followers: 1)
Rwanda Journal     Full-text available via subscription  
Scandinavian Journal of Forest Research     Hybrid Journal   (Followers: 4)
Science, Technology and Arts Research Journal     Open Access   (Followers: 1)
Silva Lusitana     Open Access  
Small-scale Forestry     Hybrid Journal   (Followers: 2)
Southern African Forestry Journal     Full-text available via subscription   (Followers: 1)
Southern Forests : a Journal of Forest Science     Hybrid Journal   (Followers: 6)
Tanzania Journal of Forestry and Nature Conservation     Full-text available via subscription   (Followers: 2)
Trees     Hybrid Journal   (Followers: 5)
Urban Forestry & Urban Greening     Hybrid Journal   (Followers: 9)
Veld & Flora     Full-text available via subscription   (Followers: 2)
Wood and Fiber Science     Full-text available via subscription   (Followers: 2)


Journal Cover Forests
  [SJR: 0.63]   [H-I: 16]   [3 followers]  Follow
  This is an Open Access Journal Open Access journal
   ISSN (Print) 1999-4907
   Published by MDPI Homepage  [148 journals]
  • Forests, Vol. 7, Pages 204: A Simulation of Image-Assisted Forest
           Monitoring for National Inventories

    • Authors: Francis Roesch
      First page: 204
      Abstract: The efficiency of national forest monitoring efforts can be increased by the judicious incorporation of ancillary data. For instance, a fixed number of ground plots might be used to inform a larger set of annual estimates by observing a smaller proportion of the plots each year while augmenting each annual estimate with ancillary data in order to reduce overall costs while maintaining a desired level of accuracy. Differencing successive geo-rectified remotely sensed images can conceivably provide forest change estimates at a scale and level of accuracy conducive to the improvement of temporally relevant forest attribute estimates. Naturally, the degree of improvement in the desired estimates is highly dependent on the relationships between the spatial-temporal scales of ground plot and remotely sensed observations and the desired spatial-temporal scale of estimation. In this paper, fixed scales of observation for each data source are used to explore the value of three different levels of information available from the remotely sensed image-change estimates. Four populations are simulated and sampled under four sampling error structures. The results show that the image change estimates (ICE) can be used to significantly reduce bias for annual estimates of harvest and mortality and that improved estimation of harvest and mortality can sometimes, but not always, contribute to better estimates of standing volume.
      PubDate: 2016-09-15
      DOI: 10.3390/f7090204
      Issue No: Vol. 7, No. 9 (2016)
  • Forests, Vol. 7, Pages 205: Fires of the Last Millennium Led to Landscapes
           Dominated by Early Successional Species in Québec’s Clay Belt Boreal
           Forest, Canada

    • Authors: Maxime Asselin, Pierre Grondin, Martin Lavoie, Bianca Fréchette
      First page: 205
      Abstract: This study presents the long-term (over the last 8000 years) natural variability of a portion of the Picea mariana-moss bioclimatic domain belonging to Québec’s Clay Belt. The landscapes are dominated by mesic-subhydric clay and early successional forests composed of Populus tremuloides, Pinus banksiana and Picea mariana. The natural variability (fires and vegetation) of one of these landscapes was reconstructed by means of pollen and macroscopic charcoal analysis of sedimentary archives from two peatlands in order to assess when and how such landscapes were formed. Following an initial afforestation period dominated by Picea (8000–6800 cal. Years BP), small and low-severity fires favored the development and maintenance of landscapes dominated by Picea and Abies balsamea during a long period (6800–1000 BP). Over the last 1000 years, fires have become more severe and covered a larger area. These fires initiated a recurrence dynamic of early successional stands maintained until today. A decline of Abies balsamea has occurred over the last centuries, while the pollen representation of Pinus banksiana has recently reached its highest abundance. We hypothesize that the fire regime of the last millennium could characterize Québec’s Clay Belt belonging to the western Picea mariana-moss and Abies balsamea-Betula papyrifera domains.
      PubDate: 2016-09-15
      DOI: 10.3390/f7090205
      Issue No: Vol. 7, No. 9 (2016)
  • Forests, Vol. 7, Pages 206: Tree Stem Diameter Estimation from Mobile
           Laser Scanning Using Line-Wise Intensity-Based Clustering

    • Authors: Mona Forsman, Johan Holmgren, Kenneth Olofsson
      First page: 206
      Abstract: Diameter at breast height has been estimated from mobile laser scanning using a new set of methods. A 2D laser scanner was mounted facing forward, tilted nine degrees downwards, on a car. The trajectory was recorded using inertial navigation and visual SLAM (simultaneous localization and mapping). The laser scanner data, the trajectory and the orientation were used to calculate a 3D point cloud. Clusters representing trees were extracted line-wise to reduce the effects of uncertainty in the positioning system. The intensity of the laser echoes was used to filter out unreliable echoes only grazing a stem. The movement was used to obtain measurements from a larger part of the stem, and multiple lines from different views were used for the circle fit. Two trigonometric methods and two circle fit methods were tested. The best results with bias 2.3% (6 mm) and root mean squared error 14% (37 mm) were acquired with the circle fit on multiple 2D projected clusters. The method was evaluated compared to field data at five test areas with approximately 300 caliper-measured trees within a 10-m working range. The results show that this method is viable for stem measurements from a moving vehicle, for example a forest harvester.
      PubDate: 2016-09-16
      DOI: 10.3390/f7090206
      Issue No: Vol. 7, No. 9 (2016)
  • Forests, Vol. 7, Pages 207: Single Tree Stem Profile Detection Using
           Terrestrial Laser Scanner Data, Flatness Saliency Features and Curvature

    • Authors: Kenneth Olofsson, Johan Holmgren
      First page: 207
      Abstract: A method for automatic stem detection and stem profile estimation based on terrestrial laser scanning (TLS) was validated. The root-mean-square error was approximately 1 cm for stem diameter estimations. The method contains a new way of extracting the flatness saliency feature using the centroid of a subset of a point cloud within a voxel cell that approximates the point by point calculations. The loss of accuracy is outweighed by a much higher computational speed, making it possible to cover large datasets. The algorithm introduces a new way to connect surface patches belonging to a stem and investigates if they belong to curved surfaces. Thereby, cylindrical objects, like stems, are found in the pre-filtering stage. The algorithm uses a new cylinder fitting method that estimates the axis direction by transforming the TLS points into a radial-angular coordinate system and evaluates the deviations by a moving window convex hull algorithm. Once the axis direction is found, the cylinder center is chosen as the position with the smallest radial deviations. The cylinder fitting method works on a point cloud in both the single-scan setup, as well as a multiple scan setup of a TLS system.
      PubDate: 2016-09-16
      DOI: 10.3390/f7090207
      Issue No: Vol. 7, No. 9 (2016)
  • Forests, Vol. 7, Pages 208: Urban Forest Indicators for Planning and
           Designing Future Forests

    • Authors: Sara Barron, Stephen Sheppard, Patrick Condon
      First page: 208
      Abstract: This paper describes a research project exploring future urban forests. This study uses a Delphi approach to develop a set of key indicators for healthy, resilient urban forests. Two groups of experts participated in the Delphi survey: International academics and local practitioners. The results of the Delphi indicate that “urban tree diversity” and “physical access to nature” are indicators of high importance. “Tree risk” and “energy conservation” were rated as indicators of relatively low importance. Results revealed some differences between academics and practitioners in terms of their rating of the indicators. The research shows that some indicators rated as high importance are not necessarily the ones measured or promoted by many municipal urban forestry programs. In particular, social indicators of human health and well-being were rated highly by participants, but not routinely measured by urban forestry programs.
      PubDate: 2016-09-16
      DOI: 10.3390/f7090208
      Issue No: Vol. 7, No. 9 (2016)
  • Forests, Vol. 7, Pages 209: Incentives and Constraints of Community and
           Smallholder Forestry

    • Authors: Wil de Jong, Glenn Galloway, Pia Katila, Pablo Pacheco
      First page: 209
      Abstract: This editorial introduces the special issue: Incentives and constraints of community and smallholder forestry. The special issue contains nine papers, listed in a table in the main text. The editorial reviews briefly some key elements of our current understanding of community and smallholder forestry. The editorial also briefly introduces the nine papers of the special issue and points out how they link to the debate among academics and specialists on community and smallholder forestry. Finally, the editorial highlights the new elements that the nine papers contribute to our understanding of community and smallholder forestry, before it concludes at the end.
      PubDate: 2016-09-16
      DOI: 10.3390/f7090209
      Issue No: Vol. 7, No. 9 (2016)
  • Forests, Vol. 7, Pages 291: The Biodiversity of Urban and Peri-Urban
           Forests and the Diverse Ecosystem Services They Provide as
           Socio-Ecological Systems

    • Authors: Stephen Livesley, Francisco Escobedo, Justin Morgenroth
      First page: 291
      Abstract: Urban and peri-urban forests provide a variety of ecosystem service benefits for urban society. Recognising and understanding the many human–tree interactions that urban forests provide may be more complex but probably just as important to our urbanised society. This paper introduces four themes that link the studies from across the globe presented in this Special Issue: (1) human–tree interactions; (2) urban tree inequity; (3) carbon sequestration in our own neighbourhoods; and (4) biodiversity of urban forests themselves and the fauna they support. Urban forests can help tackle many of the “wicked problems” that confront our towns and cities and the people that live in them. For urban forests to be accepted as an effective element of any urban adaptation strategy, we need to improve the communication of these ecosystem services and disservices and provide evidence of the benefits provided to urban society and individuals, as well as the biodiversity with which we share our town and cities.
      PubDate: 2016-11-24
      DOI: 10.3390/f7120291
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 292: A Model to Estimate Willingness to Pay for
           Harvest Permits for Wild Edible Mushrooms: Application to Andalusian

    • Authors: Pablo de Frutos, Fernando Martinez-Peña, Jorge Aldea, Pablo Campos
      First page: 292
      Abstract: Public demand for harvesting wild edible mushrooms has risen in recent decades and currently affects many forested areas around the world. The idea of introducing permits for users has been conceived as a tool for ecosystem management. The problem is that policy-makers lack the necessary means to help guide them when establishing prices for such harvesting permits. Valuing the recreational benefits which mushroom harvesters derive from harvesting wild edible mushrooms may provide certain guidelines as to how much people would be willing to pay and may also justify future payments levied on harvesters. The aim of the present article is to estimate a model for determining citizens’ willingness to pay for a harvesting permit in a forest in Andalusia (Spain) using contingent valuation methods. Results show that mean willingness to pay is 22.61 Euros (USD28.18) per harvester and season. This amount depends on several socioeconomic factors and preferences related to harvesters’ experiences.
      PubDate: 2016-11-25
      DOI: 10.3390/f7120292
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 293: The Effects of Fertilization on the Growth and
           Physiological Characteristics of Ginkgo biloba L

    • Authors: Jing Guo, Yaqiong Wu, Bo Wang, Yan Lu, Fuliang Cao, Guibin Wang
      First page: 293
      Abstract: Ginkgo biloba L. is one of the most extensively planted and productive commercial species in temperate areas around the world, but slow-growth is the most limiting factor for its utilization. Fertilization is one of the key technologies for high quality and high forest yield. To better understand the impacts of fertilization on Ginkgo productivity, the effects of fertilization treatments (single fertilizer and combined fertilizer) on growth, nutrient content in Ginkgo leaves, and photosynthesis characteristics were studied in a 10-year-old Ginkgo plantation over two years. The single factor experiments suggested that DBH (diameter at breast height), H (height), NSL (length of new shoots), and V (trunk volume) showed significant differences between the different levels of single nitrogen (N) or phosphate (P) fertilizer application. Orthogonal test results showed that the nine treatments all promoted the growth of Ginkgo, and the formula (N: 400 g·tree−1, P: 200 g·tree−1, potassium (K): 90 g·tree−1) was the most effective. Gs (stomatal conductance) and Pn (net photosynthesis rate) showed significant differences between the different amounts of single N or P fertilizer application, while single K fertilizer only affected Pn. Combined N, P, and K fertilizer had significant promoting effects on Ci (intercellular CO2 concentration), Gs and Pn. N and P contents in Ginkgo leaves showed significant differences between the different amounts of a single N fertilizer application. A single P fertilizer only improved foliar P contents in Ginkgo leaves. A single K fertilizer application improved N and K content in Ginkgo leaves. The effects of different N, P, and K fertilizer treatments on the nutrient content of Ginkgo leaves were different.
      PubDate: 2016-11-24
      DOI: 10.3390/f7120293
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 294: Assessment of Aboveground Woody Biomass
           Dynamics Using Terrestrial Laser Scanner and L-Band ALOS PALSAR Data in
           South African Savanna

    • Authors: Victor Odipo, Alecia Nickless, Christian Berger, Jussi Baade, Mikhail Urbazaev, Christian Walther, Christiane Schmullius
      First page: 294
      Abstract: The use of optical remote sensing data for savanna vegetation structure mapping is hindered by sparse and heterogeneous distribution of vegetation canopy, leading to near-similar spectral signatures among lifeforms. An additional challenge to optical sensors is the high cloud cover and unpredictable weather conditions. Longwave microwave data, with its low sensitivity to clouds addresses some of these problems, but many space borne studies are still limited by low quality structural reference data. Terrestrial laser scanning (TLS) derived canopy cover and height metrics can improve aboveground biomass (AGB) prediction at both plot and landscape level. To date, few studies have explored the strength of TLS for vegetation structural mapping, and particularly few focusing on savannas. In this study, we evaluate the potential of high resolution TLS-derived canopy cover and height metrics to estimate plot-level aboveground biomass, and to extrapolate to a landscape-wide biomass estimation using multi-temporal L-band Synthetic Aperture Radar (SAR) within a 9 km2 area savanna in Kruger National Park (KNP). We inventoried 42 field plots in the wet season and computed AGB for each plot using site-specific allometry. Canopy cover, canopy height, and their product were regressed with plot-level AGB over the TLS-footprint, while SAR backscatter was used to model dry season biomass for the years 2007, 2008, 2009, and 2010 for the study area. The results from model validation showed a significant linear relationship between TLS-derived predictors with field biomass, p < 0.05 and adjusted R2 ranging between 0.56 for SAR to 0.93 for the TLS-derived canopy cover and height. Log-transformed AGB yielded lower errors with TLS metrics compared with non-transformed AGB. An assessment of the backscatter based on root mean square error (RMSE) showed better AGB prediction with cross-polarized (RMSE = 6.6 t/ha) as opposed to co-polarized data (RMSE = 6.7 t/ha), attributed to volume scattering of woody vegetation along river valleys and streams. The AGB change analysis showed 32 ha (3.5%) of the 900 ha experienced AGB loses above an average of 5 t/ha per annum, which can mainly be attributed to the falling of trees by mega herbivores such as elephants. The study concludes that SAR data, especially L-band SAR, can be used in the detection of small changes in savanna vegetation over time.
      PubDate: 2016-11-25
      DOI: 10.3390/f7120294
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 295: Radial Growth Response of Larix gmelinii to
           Climate along a Latitudinal Gradient in the Greater Khingan Mountains,
           Northeastern China

    • Authors: Yangao Jiang, Junhui Zhang, Shijie Han, Zhenju Chen, Heikki Setälä, Jinghua Yu, Xingbo Zheng, Yingtao Guo, Yue Gu
      First page: 295
      Abstract: To explore how climatic factors influence tree growth within the context of global climate changes, we used a dendroclimatological analysis to understand the response of Larix gmelinii to climatic variations along a broad latitudinal gradient from 47.27° to 52.66° N in the Greater Khingan Mountains of Northeastern China. The growth-limiting climate factors and a detailed association between radial growth and climate were identified along the gradient using redundancy analysis (RDA) and standard correlation function analysis over the period 1960–2013. The results showed that temperatures during current June to July represented the most important factor affecting tree radial growth in the study area. Across all studied latitudes, Larix gmelinii growth might be decreasing in radial growth due to higher monthly maximum temperature (Tmax) and monthly mean temperatures (Tm) in the current June, especially for the stands at low and middle latitudes. With continued warming, Larix gmelinii radial growth at high latitudes (e.g., Mangui (MG) and Mohe (MH)) might be reduced by warmer temperatures in July. In addition, Larix gmelinii might be decreasing in radial growth from decreasing precipitation. Our results show that there is a decreasing trend in Larix gmelinii radial growth under the observed general increase of temperatures in the Greater Khingan Mountains in recent years.
      PubDate: 2016-11-28
      DOI: 10.3390/f7120295
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 296: Increasing Water Use Efficiency Comes at a
           Cost for Norway Spruce

    • Authors: Tanja Sanders, Ingo Heinrich, Björn Günther, Wolfgang Beck
      First page: 296
      Abstract: Intrinsic water use efficiency (WUEi) in trees is an indication of the ratio of carbon assimilation to the rate of transpiration. It is generally assumed that it is a response to water availability. In agricultural research, the question of drought tolerance by increased WUEi has been well studied. In general, the increase is a trade-off for productivity and is therefore not desired. For forest trees, this question is less clearly understood. Using stable carbon isotopes derived from tree rings combined with productivity as the product of the annual growth increment and annual density measurements, we compared the change in WUEi over a 15 year period. While WUEi increased over this period, the productivity decreased, causing an opposing trend. The gradient of the correlation between WUEi and productivity varies between provenances and sites. Counterintuitively, the populations at the drier site showed low WUEi values at the beginning of the investigation. Slopes vary with the provenance from Poland showing the least decline in productivity. In general, we found that a decline in productivity aligned with an increase in WUEi.
      PubDate: 2016-11-28
      DOI: 10.3390/f7120296
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 297: The Biodiversity Benefits and Opportunity
           Costs of Plantation Forest Management: A Modelling Case Study of Pinus
           radiata in New Zealand

    • Authors: Nhung Nghiem, Hop Tran
      First page: 297
      Abstract: This study modelled the potential biodiversity benefits and the opportunity costs of a patch-clear-cutting strategy over a clear-cutting strategy for Pinus radiata in New Zealand. Patch-clear cutting is a special case of clear cutting involving the removal of all the trees from strips or patches within a stand, leaving the remainder uncut or clear cutting a series of strips or patches. A forest-level optimisation model was extended to include uncertainty in timber growth, plant diversity, and cutting costs. Using a species-area relationship and economies of cutting scale, the net present value and optimal rotation age under alternative management strategies were calculated. Results suggested that the optimal rotation ages were similar (24 and 25 years) for the two cutting strategies. Patch-clear cutting provided higher biodiversity benefits (i.e., 59 vs. 11 understorey plant species) with an opportunity cost of 27 NZD (18 USD) per extra plant species or 1250 NZD (820 USD) ha−1. However, the true benefits of patch-clear cutting would be even greater if other benefits of stand retention are included. Our research can potentially inform local decision making and inform international systems of payment for environmental services, such as the REDD+ (Reducing Emissions from Deforestation and Forest Degradation) program, to conserve biodiversity in developing countries with plantation forests.
      PubDate: 2016-11-28
      DOI: 10.3390/f7120297
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 298: Drought Stress Distribution Responses of
           Continental Beech Forests at their Xeric Edge in Central Europe

    • Authors: Éva Salamon-Albert, Péter Lőrincz, Gábor Pauler, Dénes Bartha, Ferenc Horváth
      First page: 298
      Abstract: In order to develop adequate adaptation measures for environmental vulnerability, we need detailed knowledge on the climatic performance of forest ecosystems. In this study, we aim to explore climate function variability of lowland beech forest distribution at a landscape scale. We also construct the response profiles of these forests near their xeric limit under wet continental climatic conditions. We studied distribution responses using presence-absence forest records and 18 bioclimatic variables. We performed exploratory factor analysis and frequency estimation to evaluate climate function distribution responses. We found that temperature adjusted precipitation measures during summer were the most important, followed by winter rainfall indices. The relative Drought Response Range (rDRR) in the response profile presented the climate limitation function of the distribution. According to our results, higher level of climate function variability is associated with lower level of rDRR, presenting an ecological trade-off. Our results suggest that distribution functions of the rDRR, especially the Ombrothermic index, can be used as landscape indicators of drought stress. Consequently, rDRR could be a useful measure to assess regional climatic vulnerability of forest occurrence and distribution patterns.
      PubDate: 2016-11-29
      DOI: 10.3390/f7120298
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 300: Transforming Justice in REDD+ through a
           Politics of Difference Approach

    • Authors: Kimberly Marion Suiseeya
      First page: 300
      Abstract: Since Reduced Emissions from Deforestation and Degradation “Plus” (REDD+) starting gaining traction in the UN climate negotiations in 2007, its architects and scholars have grappled with its community-level justice implications. On the one hand, supporters argue that REDD+ will help the environment and forest-dependent communities by generating payments for forest carbon services from industrialized countries seeking lower cost emissions reductions. Critics, by contrast, increasingly argue that REDD+ is a new form of colonization through capitalism, producing injustice by stripping forest communities of their rights, denying them capabilities for wellbeing, and rendering forest peoples voiceless in forest governance. This paper argues that current REDD+ debates are too focused on relatively simple visions of either distributive or procedural justice, and pay too little attention to the core recognitional justice concerns of REDD+ critics, namely questions of what values, worldviews, rights, and identities are privileged or displaced in the emergence, design, and implementation of REDD+ and with what effects. This paper examines the tensions that emerge when designing institutions to promote multi-scalar, multivalent justice in REDD+ to ask: what are the justice demands that REDD+ architects face when designing REDD+ institutions? Complexifying the concepts of justice as deployed in the debates on REDD+ can illuminate the possibilities for a diversity of alternative perspectives to generate new institutional design ideas for REDD+.
      PubDate: 2016-11-30
      DOI: 10.3390/f7120300
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 302: Estimation of Nutrient Exports Resulting from
           Thinning and Intensive Biomass Extraction in Medium-Aged Spruce and Pine
           Stands in Saxony, Northeast Germany

    • Authors: Christine Knust, Karoline Schua, Karl-Heinz Feger
      First page: 302
      Abstract: A growing interest in using forest biomass for bioenergy generation may stimulate intensive harvesting scenarios in Germany. We calculated and compared nutrient exports of conventional stem only (SO), whole tree without needles (WT excl. needles), and whole tree (WT) harvesting in two medium aged Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) stands differing in productivity, and related them to soil nutrient pools and fluxes at the study sites. We established allometric biomass functions for each aboveground tree compartment and analyzed their nutrient contents. We analyzed soil nutrient stocks, estimated weathering rates, and obtained deposition and seepage data from nearby Level II stations. WT (excl. needles) and WT treatments cause nutrient losses 1.5 to 3.6 times higher than SO, while the biomass gain is only 1.18 to 1.25 in case of WT (excl. needles) and 1.28 to 1.30 in case of WT in the pine and spruce stand, respectively. Within the investigated 25-year period, WT harvesting would cause exports of N, K+, Ca2+, and Mg2+ of 6.6, 8.8, 5.4, and 0.8 kg·ha−1 in the pine stand and 13.9, 7.0, 10.6, and 1.8 kg·ha−1 in the spruce stand annually. The relative impact of WT and WT (excl. needles) on the nutrient balance is similar in the pine and spruce stands, despite differences in stand productivities, and thus the absolute amount of nutrients removed. In addition to the impact of intensive harvesting, both sites are characterized by high seepage losses of base cations, further impairing the nutrient budget. While intensive biomass extraction causes detrimental effects on many key soil ecological properties, our calculations may serve to implement measures to improve the nutrient balance in forested ecosystems.
      PubDate: 2016-11-30
      DOI: 10.3390/f7120302
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 303: Evaluation of Whole Tree Growth Increment
           Derived from Tree-Ring Series for Use in Assessments of Changes in Forest
           Productivity across Various Spatial Scales

    • Authors: Juha Metsaranta, Jagtar Bhatti
      First page: 303
      Abstract: The inherent predictability of inter-annual variation in forest productivity remains unknown. Available field-based data sources for understanding this variability differ in their spatial resolution, temporal resolution, and typical units of measure. Nearly all other tree and forest characteristics are in practice derived from measurements of diameter at breast height (DBH). Therefore, diameter increment reconstructed annually from tree-ring data can be used to estimate annual growth increments of wood volume, but the accuracy and precision of these estimates requires assessment. Annual growth estimates for n = 170 trees sampled for whole stem analysis from five tree species (jack pine, lodgepole pine, black spruce, white spruce, and trembling aspen) in Western Canada were compared against increments derived from breast height measurements only. Inter-annual variability of breast height and whole tree growth increments was highly correlated for most trees. Relative errors varied by species, diameter class, and the equation used to estimate volume (regional vs. national). A simple example of the possible effect of this error when propagated to the stand level is provided.
      PubDate: 2016-12-01
      DOI: 10.3390/f7120303
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 304: Assessment of Geographic Information System
           (GIS) Skills Employed by Graduates from Three Forestry Programs in the
           United States

    • Authors: Krista Merry, Pete Bettinger, Donald Grebner, Kevin Boston, Jacek Siry
      First page: 304
      Abstract: This research evaluates the current use of geographic information systems (GIS) by forestry program graduates employed in the United States who graduated from university in the past five years. The purpose was to understand what geospatial processes and databases are typically used by field foresters. A survey was designed and sent to recent forestry graduates from Mississippi State University, Oregon State University, and the University of Georgia, with 30% of those surveyed choosing to participate. The majority of forestry graduates surveyed use GIS at least once a week, and the most frequently employed tasks included editing tabular data, adjusting polygon boundaries, buffering and splitting polygons, and querying for spatial and tabular information. Very few overlay or advance spatial analysis tools were noted as used in regular work efforts. Most respondents use digital aerial photographs as reference, along with satellite images. LiDAR is increasingly being used by these foresters, but to a lesser extent. ArcMap and Google Earth were noted as the most commonly used software packages. Most foresters rely on an organization’s technical support staff for assistance. The study results can be used as a guide for academic programs in their efforts to provide timely and effective knowledge on geospatial topics to forestry undergraduate students.
      PubDate: 2016-12-01
      DOI: 10.3390/f7120304
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 305: Mapping Long-Term Changes in Mangrove Species
           Composition and Distribution in the Sundarbans

    • Authors: Manoj Ghosh, Lalit Kumar, Chandan Roy
      First page: 305
      Abstract: The Sundarbans mangrove forest is an important resource for the people of the Ganges Delta. It plays an important role in the local as well as global ecosystem by absorbing carbon dioxide and other pollutants from air and water, offering protection to millions of people in the Ganges Delta against cyclone and water surges, stabilizing the shore line, trapping sediment and nutrients, purifying water, and providing services for human beings, such as fuel wood, medicine, food, and construction materials. However, this mangrove ecosystem is under threat, mainly due to climate change and anthropogenic factors. Anthropogenic and climate change-induced degradation, such as over-exploitation of timber and pollution, sea level rise, coastal erosion, increasing salinity, effects of increasing number of cyclones and higher levels of storm surges function as recurrent threats to mangroves in the Sundarbans. In this situation, regular and detailed information on mangrove species composition, their spatial distribution and the changes taking place over time is very important for a thorough understanding of mangrove biodiversity, and this information can also lead to the adoption of management practices designed for the maximum sustainable yield of the Sundarbans forest resources. We employed a maximum likelihood classifier technique to classify images recorded by the Landsat satellite series and used post classification comparison techniques to detect changes at the species level. The image classification resulted in overall accuracies of 72%, 83%, 79% and 89% for the images of 1977, 1989, 2000 and 2015, respectively. We identified five major mangrove species and detected changes over the 38-year (1977–2015) study period. During this period, both Heritiera fomes and Excoecaria agallocha decreased by 9.9%, while Ceriops decandra, Sonneratia apelatala, and Xylocarpus mekongensis increased by 12.9%, 380.4% and 57.3%, respectively.
      PubDate: 2016-12-03
      DOI: 10.3390/f7120305
      Issue No: Vol. 7, No. 12 (2016)
  • Forests, Vol. 7, Pages 250: Modeling Anthropogenic Fire Occurrence in the
           Boreal Forest of China Using Logistic Regression and Random Forests

    • Authors: Futao Guo, Lianjun Zhang, Sen Jin, Mulualem Tigabu, Zhangwen Su, Wenhui Wang
      First page: 250
      Abstract: Frequent and intense anthropogenic fires present meaningful challenges to forest management in the boreal forest of China. Understanding the underlying drivers of human-caused fire occurrence is crucial for making effective and scientifically-based forest fire management plans. In this study, we applied logistic regression (LR) and Random Forests (RF) to identify important biophysical and anthropogenic factors that help to explain the likelihood of anthropogenic fires in the Chinese boreal forest. Results showed that the anthropogenic fires were more likely to occur at areas close to railways and were significantly influenced by forest types. In addition, distance to settlement and distance to road were identified as important predictors for anthropogenic fire occurrence. The model comparison indicated that RF had greater ability than LR to predict forest fires caused by human activity in the Chinese boreal forest. High fire risk zones in the study area were identified based on RF, where we recommend increasing allocation of fire management resources.
      PubDate: 2016-10-25
      DOI: 10.3390/f7110250
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 251: Protective Effect of Nitric Oxide (NO) against
           Oxidative Damage in Larix gmelinii Seedlings under Ultraviolet-B

    • Authors: Haiqing Hu, Zhenbao Zhou, Xiaoxin Sun, Zhonghua Zhang, Qinghuan Meng
      First page: 251
      Abstract: Ultraviolet-B (UV-B) stress appears to be more striking than other research works because of the thin ozone layer. The protective influence of an exogenous nitric oxide donor and sodium nitroprusside (SNP) on the growth properties of Larix gmelinii seedlings was investigated under ultraviolet-B radiation conditions. The results indicated that 0.1 mM SNP could effectively alleviate the damage caused by ultraviolet-B radiation, and improved the seedling growth properties, the relative water content, and photosynthetic pigment content in leaves. Additionally, the photosynthetic capacity and antioxidant enzyme activity were increased during the exposure. On the contrary, the damage caused by active oxygen was decreased in SNP-treated seedling leaves. The damage caused by ultraviolet-B radiation was slightly reduced after treating with 0.01 mM SNP. Nevertheless, treatment with 0.5 mM SNP had a negative effect under ultraviolet-B radiation. Furthermore, supplementing NO (nitric oxide) improved the photosynthetic capacity and antioxidant enzyme activity and alleviated the damage of caused by active oxygen. The best effective concentration of SNP was 0.1 mM. Therefore, a suitable amount of exogenous NO can protect the Larix gmelinii seedlings and increase their tolerance to ultraviolet-B radiation.
      PubDate: 2016-10-26
      DOI: 10.3390/f7110251
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 252: Automating Plot-Level Stem Analysis from
           Terrestrial Laser Scanning

    • Authors: Zhouxin Xi, Christopher Hopkinson, Laura Chasmer
      First page: 252
      Abstract: Terrestrial laser scanning (TLS) provides an accurate means of analyzing individual tree attributes, and can be extended to plots using multiple TLS scans. However, multiple TLS scans may reduce the effectiveness of individual tree structure quantification, often due to understory occupation, mutual tree occlusion, and other influences. The procedure to delineate accurate tree attributes from plot scans involves onerous steps and automated integration is challenging in the literature. This study proposes a fully automatic approach composed of ground filtering, stem detection, and stem form extraction algorithms, with emphasis on accuracy and feasibility. The delineated attributes can be useful to analyze terrain, tree biomass and fiber quality. The automation was experimented on a mature pine plot in Finland with both single scan (SS) and multiple scans (MS) datasets. With mensuration as reference, digital terrain models (DTM), stem locations, diameters at breast height (DBHs), stem heights, and stem forms of the whole plot were extracted and validated. Results of this study were best using the multiple scans (MS) dataset, where 76% of stems were detected (n = 49). Height extraction accuracy was 0.68 (r2) and 1.7 m (RMSE), and DBH extraction accuracy was 0.97 (r2) and 0.90 cm (RMSE). Height-wise stem diameter extraction accuracy was 0.76 (r2) and 2.4 cm (RMSE).
      PubDate: 2016-10-28
      DOI: 10.3390/f7110252
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 253: Genetic Improvement of Wood Properties in
           Pinus kesiya Royle ex Gordon for Sawn Timber Production in Malawi

    • Authors: Edward Missanjo, Junji Matsumura
      First page: 253
      Abstract: Accurate prediction of genetic potential and response to selection in breeding requires knowledge of genetic parameters for important selection traits. In this study, we estimated genetic parameters for wood properties in Khasi pine (Pinus kesiya Royle ex Gordon) grown in Malawi. Data on wood properties and growth traits were collected from six families of Pinus kesiya at the age of 30. The results show that wood density had a higher genetic control (h2 = 0.595 ± 0.055) than wood stiffness (h2 = 0.559 ± 0.038) and wood strength (h2 = 0.542 ± 0.091). The genetic correlation among wood quality traits was significantly moderate (0.464 ± 0.061) to high (0.735 ± 0.025). The predicted genetic response indicated that selection for wood density at 10% selection intensity would increase stiffness and strength by 12.6% and 8.85%, respectively. The genetic correlations between growth and wood quality traits were moderately unfavourable. However, sufficient variation exists within the breeding population to select individuals with both good growth rate and high wood quality traits. It is therefore suggested that all trees with both diameter at breast height (DBH) greater than 32.0 cm and density greater than 0.593 g/cm3 must be selected in order to increase the efficiency of the breeding programme. However, in the long term, it is recommended that the best selection strategy would be to develop a multiple-trait selection index. The selection index should be developed using optimal index weights for the advanced Pinus kesiya breeding programme in Malawi.
      PubDate: 2016-10-27
      DOI: 10.3390/f7110253
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 254: Anthropogenic Disturbances Create a New
           Vegetation Toposequence in the Gatineau River Valley, Quebec

    • Authors: Jason Laflamme, Alison Munson, Pierre Grondin, Dominique Arseneault
      First page: 254
      Abstract: This study measured changes in forest composition that have occurred since the preindustrial era along the toposequence of the Gatineau River Valley, Quebec, Canada (5650 km2), based on survey records prior to colonization (1804–1864) and recent forest inventories (1982–2006). Changes in forest cover composition over time were found to be specific to toposequence position. Maple and red oak are now more frequent on upper toposequence positions (+26%, +21%, respectively), whereas yellow birch, eastern hemlock, and American beech declined markedly (−34% to −17%). Poplar is more frequent throughout the landscape, but particularly on mid-toposequence positions (+40%). In contrast, white pine, frequent on all toposequence positions in the preindustrial forest, is now confined to shallow and coarse-textured soils (−20%). The preindustrial forest types of the study area were mostly dominated by maple, yellow birch, and beech, with strong components of white pine, hemlock, and eastern white cedar, either as dominant or codominant species. In a context of ongoing anthropogenic disturbances and environmental changes, it is probably not possible to restore many of these types, except where targeted silvicultural interventions could increase the presence of certain species. The new forest types observed should be managed to ensure continuity of vital ecosystem services and functions as disturbance regimes evolve.
      PubDate: 2016-10-28
      DOI: 10.3390/f7110254
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 255: Enhancing Forest Growth and Yield Predictions
           with Airborne Laser Scanning Data: Increasing Spatial Detail and
           Optimizing Yield Curve Selection through Template Matching

    • Authors: Piotr Tompalski, Nicholas Coops, Joanne White, Michael Wulder
      First page: 255
      Abstract: Accurate information on both the current stock and future growth and yield of forest resources is critical for sustainable forest management. We demonstrate a novel approach to utilizing airborne laser scanning (ALS)-derived forest stand attributes to determine future growth and yield of six attributes at a sub-stand (25 m grid cell) level of detail: dominant height (HMAX), Lorey’s height (HL), quadratic mean diameter (QMD), basal area (BA), whole stem volume (V), and trees per hectare (TPH). The approach is designed to find the most appropriate matching yield curve and project the attributes to the age of 80 years. Comparisons to conventional plot-level projections resulted in relative mean differences of 13.4% (HMAX), −27.1% (HL), 18.8% (QMD), 12.0% (BA), 18.6% (V), and −17.5% (TPH). The respective relative root mean squared difference values were: 31.1%, 38.4%, 19.8%, 19.8%, 21.8%, and 38.4%. Differences were driven mostly by stand-level age and site index. The uncertainty of cell-level yield curve assignment was used to refine stand-level summaries. The novel contribution of this study is in the application of growth and yield models at the cell level, combined with the use of ALS-derived attributes to optimize yield curve selection via template matching.
      PubDate: 2016-10-28
      DOI: 10.3390/f7110255
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 256: Seasonal Variation in Soil Greenhouse Gas
           Emissions at Three Age-Stages of Dawn Redwood (Metasequoia
           glyptostroboides) Stands in an Alluvial Island, Eastern China

    • Authors: Shan Yin, Xianxian Zhang, Jukka Pumpanen, Guangrong Shen, Feng Xiong, Chunjiang Liu
      First page: 256
      Abstract: Greenhouse gas (GHG) emissions are an important part of the carbon (C) and nitrogen (N) cycle in forest soil. However, soil greenhouse gas emissions in dawn redwood (Metasequoia glyptostroboides) stands of different ages are poorly understood. To elucidate the effect of plantation age and environmental factors on soil GHG emissions, we used static chamber/gas chromatography (GC) system to measure soil GHG emissions in an alluvial island in eastern China for two consecutive years. The soil was a source of CO2 and N2O and a sink of CH4 with annual emissions of 5.5–7.1 Mg C ha−1 year−1, 0.15–0.36 kg N ha−1 year−1, and 1.7–4.5 kg C ha−1 year−1, respectively. A clear exponential correlation was found between soil temperature and CO2 emission, but a negative linear correlation was found between soil water content and CO2 emission. Soil temperature had a significantly positive effect on CH4 uptake and N2O emission, whereas no significant correlation was found between CH4 uptake and soil water content, and N2O emission and soil water content. These results implied that older forest stands might cause more GHG emissions from the soil into the atmosphere because of higher litter/root biomass and soil carbon/nitrogen content compared with younger stands.
      PubDate: 2016-11-04
      DOI: 10.3390/f7110256
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 257: Effects of Boreal Timber Rafting on the
           Composition of Arctic Driftwood

    • Authors: Lena Hellmann, Alexander Kirdyanov, Ulf Büntgen
      First page: 257
      Abstract: Wood from the boreal forest represents an important resource for paper production and sawmill processing. Due to poor infrastructure and high transportation costs on land, timbers are often transported over long distances along large river systems. Industrial river rafting activities started at the end of the 19th century and were intensified in western Russia and central Siberia from the 1920s to the 1980s. After initial single stem rafting, timber is today mostly floated in ship-guided rafts. Lost wood can be transported further to the Arctic Ocean, where it may drift within sea ice over several years and thousands of kilometers before being deposited along (sub-)Arctic coastlines. Here, we introduce dendro-dated tree-ring width series of 383 driftwood samples from logged timber that were collected along different driftwood-recipient coastlines in Greenland, Iceland and Svalbard. The majority of driftwood is Pinus sylvestris from the southern Yenisei region in central Siberia, whereas Larix sp. and Picea sp. from western Russia and eastern Siberia are rare. Although our results are based on a small sample collection, they clearly show the importance of timber rafting on species, age and origin of Arctic driftwood and indicate the immense loss of material during wood industrial river floating.
      PubDate: 2016-10-31
      DOI: 10.3390/f7110257
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 258: Distribution of Natural and Planted Forests in
           the Yanhe River Catchment: Have We Planted Trees on the Right Sites?

    • Authors: Haijing Shi, Zhongming Wen, David Paull, Feng Jiao
      First page: 258
      Abstract: Planting trees on the right sites is the first principle in silviculture, but it is not easy to apply at a large scale, especially in complex terrain such as mountainous regions. In hilly and gully landscapes of China’s Loess Plateau, the environmental heterogeneity is so great that it is very difficult to choose the right sites for planting trees. The long history of vegetation destruction makes it difficult to have a reference for restoration programs. In this paper, we compared the distribution of actual forest to an existing potential natural vegetation (PNV) map to see the mismatch with the sites. The differences in environmental conditions between natural forest and mismatched planted forest were investigated. The results showed that significant differences existed in the environmental conditions between them. The mean rainfall and temperature for natural forest were 512.20 ± 11.42 mm and 8.23 ± 0.55 °C, respectively, but 497.96 ± 14.92 mm and 8.72 ± 0.97 °C, respectively, for the mismatched planted forest. Evaporation was not only different in range (816–953 mm vs. 816–1023 mm), but also significantly different in mean values (888.31 ± 14.35 mm natural forest vs. 895.90 ± 30.55 mm planted forest). The slope gradient of natural forest and mismatched planted forest was also significantly different (22.66° ± 8.82° vs. 24.24° ± 9.86°). The results identified that 58% of the existing forest in the Yanhe River catchment is planted forest that grows on steeper slopes, receives lower rainfall, has higher temperatures and higher evaporation. The average soil water content for sites with planted forest was found to be 5.98% ± 0.32% compared to 7.52% ± 0.33% for natural forest. We conclude that the main cause of dwarfed, slender, low productive and sparse planted forest in the Loess Plateau is planting trees at unsuitable sites. Our results highlight the importance of matching sites with the best potential vegetation types. Instead of using water harvesting techniques, we suggest that more focus should be placed on understanding environmental heterogeneity and its capacity to support particular vegetation types. This study is instructive for vegetation restoration planning and existing planted forest management in the future.
      PubDate: 2016-10-31
      DOI: 10.3390/f7110258
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 259: Estimation of Voxel-Based Above-Ground Biomass
           Using Airborne LiDAR Data in an Intact Tropical Rain Forest, Brunei

    • Authors: Eunji Kim, Woo-Kyun Lee, Mihae Yoon, Jong-Yeol Lee, Yowhan Son, Kamariah Abu Salim
      First page: 259
      Abstract: The advancement of LiDAR technology has enabled more detailed evaluations of forest structures. The so-called “Volumetric pixel (voxel)” has emerged as a new comprehensive approach. The purpose of this study was to estimate plot-level above-ground biomass (AGB) in different plot sizes of 20 m × 20 m and 30 m × 30 m, and to develop a regression model for AGB prediction. Both point cloud-based (PCB) and voxel-based (VB) metrics were used to maximize the efficiency of low-density LiDAR data within a dense forest. Multiple regression model AGB prediction performance was found to be greatest in the 30 m × 30 m plots, with R2, adjusted R2, and standard deviation values of 0.92, 0.87, and 35.13 Mg∙ha−1, respectively. Five out of the eight selected independent variables were derived from VB metrics and the other three were derived from PCB metrics. Validation of accuracy yielded RMSE and NRMSE values of 27.8 Mg∙ha−1 and 9.2%, respectively, which is a reasonable estimate for this structurally complex intact forest that has shown high NRMSE values in previous studies. This voxel-based approach enables a greater understanding of complex forest structure and is expected to contribute to the advancement of forest carbon quantification techniques.
      PubDate: 2016-10-31
      DOI: 10.3390/f7110259
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 260: Thousand Cankers Disease Complex: A Forest
           Health Issue that Threatens Juglans Species across the U.S.

    • Authors: Dixie Daniels, Katheryne Nix, Phillip Wadl, Lisa Vito, Gregory Wiggins, Mark Windham, Bonnie Ownley, Paris Lambdin, Jerome Grant, Paul Merten, William Klingeman, Denita Hadziabdic
      First page: 260
      Abstract: Thousand Cankers Disease (TCD) is a disease complex wherein the fungus (Geosmithia morbida) is vectored by the walnut twig beetle (WTB, Pityophthorus juglandis). The disease causes mortality primarily of eastern black walnut (Juglans nigra), although other walnut and wingnut (Pterocarya) species are also susceptible. Black walnut is native to the Eastern and Midwestern U.S. but is widely planted in western states. Total standing volume in both urban and forested settings is approximately 96 million cubic meters, and is valued at $539 billion. Although native to the Southwestern U.S., the range of WTB has expanded considerably. The spread of G. morbida coincides with that of WTB. TCD was introduced into Tennessee in 2010, and has spread to seven eastern states. Trees infected with TCD exhibit drought-like symptoms, making field detection difficult without molecular and/or morphological methods. The recently sequenced G. morbida genome will provide valuable research tools focused on understanding gene interactions between organisms involved in TCD and mechanisms of pathogenicity. With no chemical treatments available, quarantine and sanitation are preeminent options for slowing the spread of TCD, although biological control agents have been discovered. High levels of black walnut mortality due to TCD will have far-reaching implications for both eastern and western states.
      PubDate: 2016-11-03
      DOI: 10.3390/f7110260
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 261: Grand Fir Nutrient Management in the Inland
           Northwestern USA

    • Authors: Dennis Parent, Mark Coleman
      First page: 261
      Abstract: Grand fir (Abies grandis (Douglas ex D. Don) Lindley) is widely distributed in the moist forests of the Inland Northwest. It has high potential productivity, its growth being nearly equal to western white pine, the most productive species in the region. There are large standing volumes of grand fir in the region. Nutritionally, the species has higher foliage cation concentrations than associated conifers, especially potassium (K) and calcium (Ca). In contrast, it has lower nitrogen (N) foliage concentrations, which creates favorable nutrient balance on N-limited sites. Despite concentration differences, grand fir stores proportionally more nutrients per tree than associated species because of greater crown biomass. Although few fertilization trials have examined grand fir specifically, its response is inferred from its occurrence in many monitored mixed conifer stands. Fertilization trials including grand fir either as a major or minor component show that it has a strong diameter and height growth response ranging from 15% to 50% depending in part on site moisture availability and soil geology. Grand fir tends to have a longer response duration than other inland conifers. When executed concurrently with thinning, fertilization often increases the total response. Late rotation application of N provides solid investment returns in carefully selected stands. Although there are still challenges with the post-fertilization effects on tree mortality, grand fir will continue to be an important species with good economic values and beneficial responses to fertilization and nutrient management.
      PubDate: 2016-11-04
      DOI: 10.3390/f7110261
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 262: Fire Regime Characteristics along
           Environmental Gradients in Spain

    • Authors: María Moreno, Emilio Chuvieco
      First page: 262
      Abstract: Concern regarding global change has increased the need to understand the relationship between fire regime characteristics and the environment. Pyrogeographical theory suggests that fire regimes are constrained by climate, vegetation and fire ignition processes, but it is not obvious how fire regime characteristics are related to those factors. We used a three-matrix approach with a multivariate statistical methodology that combined an ordination method and fourth-corner analysis for hypothesis testing to investigate the relationship between fire regime characteristics and environmental gradients across Spain. Our results suggest that fire regime characteristics (i.e., density and seasonality of fire activity) are constrained primarily by direct gradients based on climate, population, and resource gradients based on forest potential productivity. Our results can be used to establish a predictive model for how fire regimes emerge in order to support fire management, particularly as global environmental changes impact fire regime characteristics.
      PubDate: 2016-11-04
      DOI: 10.3390/f7110262
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 263: Mitigating the Stress of Drought on Soil
           Respiration by Selective Thinning: Contrasting Effects of Drought on Soil
           Respiration of Two Oak Species in a Mediterranean Forest

    • Authors: Chao-Ting Chang, Dominik Sperlich, Santiago Sabaté, Elisenda Sánchez-Costa, Miriam Cotillas, Josep Espelta, Carlos Gracia
      First page: 263
      Abstract: Drought has been shown to reduce soil respiration (SR) in previous studies. Meanwhile, studies of the effect of forest management on SR yielded contrasting results. However, little is known about the combined effect of drought and forest management on SR. To investigate if the drought stress on SR can be mitigated by thinning, we implemented plots of selective thinning and 15% reduced rainfall in a mixed forest consisting of the evergreen Quercus ilex and deciduous Quercus cerrioides; we measured SR seasonally from 2004 to 2007. Our results showed a clear soil moisture threshold of 9%; above this value, SR was strongly dependent on soil temperature, with Q10 of 3.0–3.8. Below this threshold, the relationship between SR and soil temperature weakened. We observed contrasting responses of SR of target oak species to drought and thinning. Reduced rainfall had a strong negative impact on SR of Q. cerrioides, whereas the effect on SR for Q. ilex was marginal or even positive. Meanwhile, selective thinning increased SR of Q. cerrioides, but reduced that of Q. ilex. Overall, our results showed that the negative effect of drought on SR can be offset through selective thinning, but the effect is attenuated with time.
      PubDate: 2016-11-04
      DOI: 10.3390/f7110263
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 264: Effects of Hurricane-Felled Tree Trunks on
           Soil Carbon, Nitrogen, Microbial Biomass, and Root Length in a Wet
           Tropical Forest

    • Authors: D. Lodge, Dirk Winter, Grizelle González, Naomi Clum
      First page: 264
      Abstract: Decaying coarse woody debris can affect the underlying soil either by augmenting nutrients that can be exploited by tree roots, or by diminishing nutrient availability through stimulation of microbial nutrient immobilization. We analyzed C, N, microbial biomass C and root length in closely paired soil samples taken under versus 20–50 cm away from large trunks of two species felled by Hugo (1989) and Georges (1998) three times during wet and dry seasons over the two years following the study conducted by Georges. Soil microbial biomass, % C and % N were significantly higher under than away from logs felled by both hurricanes (i.e., 1989 and 1998), at all sampling times and at both depths (0–10 and 10–20 cm). Frass from wood boring beetles may contribute to early effects. Root length was greater away from logs during the dry season, and under logs in the wet season. Root length was correlated with microbial biomass C, soil N and soil moisture (R = 0.36, 0.18, and 0.27, respectively; all p values < 0.05). Microbial biomass C varied significantly among seasons but differences between positions (under vs. away) were only suggestive. Microbial C was correlated with soil N (R = 0.35). Surface soil on the upslope side of the logs had significantly more N and microbial biomass, likely from accumulation of leaf litter above the logs on steep slopes. We conclude that decaying wood can provide ephemeral resources that are exploited by tree roots during some seasons.
      PubDate: 2016-11-04
      DOI: 10.3390/f7110264
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 265: Effects of Lakes on Wildfire Activity in the
           Boreal Forests of Saskatchewan, Canada

    • Authors: Scott Nielsen, Evan DeLancey, Krista Reinhardt, Marc-André Parisien
      First page: 265
      Abstract: Large lakes can act as firebreaks resulting in distinct patterns in the forest mosaic. Although this is well acknowledged, much less is known about how wildfire is affected by different landscape measures of water and their interactions. Here we examine how these factors relate to historic patterns of wildfire over a 35-year period (1980–2014) for the boreal forest of Saskatchewan, Canada. This includes the amount of water in different-sized neighborhoods, the presence of islands, and the direction, distance, and shape of nearest lake of different sizes. All individual factors affected wildfire presence, with lake sizes ≥5000 ha and amount of water within a 1000-ha surrounding area the most supported spatial scales. Overall, wildfires were two-times less likely on islands, more likely further from lakes that were circular in shape, and in areas with less surrounding water. Interactive effects were common, including the effect of direction to lake as a function of distance from lakeshore and amount of surrounding water. Our results point to a strong, but complex, bottom-up control of local wildfire activity based on the configuration of natural firebreaks. In fact, fire rotation periods predicted for one area varied more than 15-fold (<47 to >700 years) depending on local patterns in lakes. Old-growth forests within this fire-prone ecosystem are therefore likely to depend on the surrounding configuration of larger lakes.
      PubDate: 2016-11-05
      DOI: 10.3390/f7110265
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 266: Growth Characteristics of Ectomycorrhizal
           Seedlings of Quercus glauca, Quercus salicina, Quercus myrsinaefolia, and
           Castanopsis cuspidata Planted in Calcareous Soil

    • Authors: Masazumi Kayama, Takashi Yamanaka
      First page: 266
      Abstract: To verify the acclimation capacity of evergreen Fagaceae species on calcareous soil, we compared ecophysiological traits between Quercus glauca Thunb., Q. salicina Blume, Q. myrsinaefolia Blume, and Castanopsis cuspidata (Thunb.) Schottky as typical woody species from southwestern Japan. We also examined the inoculation effects of the ectomycorrhizal (ECM) fungi Astraeus hygrometricus and Scleroderma citrinum, and planted seedlings in calcareous soil collected from a limestone quarry. We measured growth, ectomycorrhizal colonization, photosynthetic rate, and concentrations of nutrients in plant organs for A. hygrometricus-inoculated, S. citrinum-inoculated, and non-ECM seedlings. Six months after planting on calcareous soil, seedlings of the three Quercus species inoculated with A. hygrometricus were larger than non-ECM seedlings, especially Q. salicina, which showed the greatest increase in dry mass. The dry mass of C. cuspidata seedlings was inferior to that of the three Quercus species. In the nutrient-uptake analysis, phosphorus, manganese, and iron uptakes were suppressed in calcareous soil for each Fagaceae species. However, seedlings of Fagaceae species that showed better growth had increased concentrations of phosphorus in roots. We concluded that seedlings of Q. salicina and Q. glauca inoculated with A. hygrometricus were best suited to calcareous soil and were considered as useful species for the reforestation in limestone quarries.
      PubDate: 2016-11-05
      DOI: 10.3390/f7110266
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 267: Spatial Distribution of Soil Nitrogen,
           Phosphorus and Potassium Stocks in Moso Bamboo Forests in Subtropical

    • Authors: Xiaolu Tang, Mingpeng Xia, Fengying Guan, Shaohui Fan
      First page: 267
      Abstract: Moso bamboo is famous for fast growth and biomass accumulation, as well as high annual output for timber and bamboo shoots. These high outputs require high nutrient inputs to maintain and improve stand productivity. Soil nitrogen (N), phosphorus (P), and potassium (K) are important macronutrients for plant growth and productivity. Due to high variability of soils, analysing spatial patterns of soil N, P, and K stocks is necessary for scientific nutrient management of Moso bamboo forests. In this study, soils were sampled from 138 locations across Yong’an City and ordinary kriging was applied for spatial interpolation of soil N, P, and K stocks within 0–60 cm. The nugget-to-sill ratio suggested a strong spatial dependence for soil N stock and a moderate spatial dependence for soil P and K stocks, indicating that soil N stock was mainly controlled by intrinsic factors while soil P and K stocks were controlled by both intrinsic and extrinsic factors. Different spatial patterns were observed for soil N, P, and K stocks across the study area, indicating that fertilizations with different ratios of N:P:K should be applied for different sites to maintain and improve stand productivity. The total soil N, P, and K stocks within 0–60 cm were 0.624, 0.020, and 0.583 Tg, respectively, indicating soils were important pools for N, P, and K.
      PubDate: 2016-11-07
      DOI: 10.3390/f7110267
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 268: Developing and Implementing Climate Change
           Adaptation Options in Forest Ecosystems: A Case Study in Southwestern
           Oregon, USA

    • Authors: Jessica Halofsky, David Peterson, Kerry Metlen, M. Myer, V. Sample
      First page: 268
      Abstract: Climate change will likely have significant effects on forest ecosystems worldwide. In Mediterranean regions, such as that in southwestern Oregon, USA, changes will likely be driven mainly by wildfire and drought. To minimize the negative effects of climate change, resource managers require tools and information to assess climate change vulnerabilities and to develop and implement adaptation actions. We developed an approach to facilitate development and implementation of climate change adaptation options in forest management. This approach, applied in a southwestern Oregon study region, involved establishment of a science–manager partnership, a science-based assessment of forest and woodland vulnerabilities to climate change, climate change education in multiple formats, hands-on development of adaptation options, and application of tools to incorporate climate change in planned projects. Through this approach, we improved local manager understanding of the potential effects of climate change in southwestern Oregon, and enabled evaluation of proposed management activities in the context of climatic stressors. Engaging managers throughout the project increased ownership of the process and outcomes, as well as the applicability of the adaptation options to on-the-ground actions. Science–management partnerships can effectively incorporate evolving science, regardless of the socio-political environment, and facilitate timely progress in adaptation to climate change.
      PubDate: 2016-11-07
      DOI: 10.3390/f7110268
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 269: Soil and Stocking Effects on Caliciopsis
           Canker of Pinus strobus L.

    • Authors: Isabel Munck, Thomas Luther, Stephen Wyka, Donald Keirstead, Kimberly McCracken, William Ostrofsky, Wayne Searles, Kyle Lombard, Jennifer Weimer, Bruce Allen
      First page: 269
      Abstract: Soil and stand density were found to be promising predictive variables associated with damage by the emerging disease of eastern white pine, Caliciopsis canker, in a 2014 survey with randomly selected eastern white pine (Pinus strobus L.) stands. The objective of this study was to further investigate the relationship between soil and stocking in eastern white pine forests of New England by stratifying sampling across soils and measuring stand density more systematically. A total of 62 eastern white pine stands were sampled during 2015–2016. Stands were stratified across soil groups and several prism plots were established at each site to measure stand density and determine stocking. Caliciopsis canker incidence in mature trees was greater in sites with drier or shallow soils compared to sites with loamy soils and in adequately stocked stands compared to understocked stands (p < 0.0001). Caliciopsis canker signs and symptoms were observed in all size classes. Live crown ratio, a measure of forest health, decreased with increasing Caliciopsis canker symptom severity. The fungal pathogen, Caliciopsis pinea Peck, was successfully isolated from cankers on trees growing in each soil group. Forest managers will need to consider damage caused by Caliciopsis canker related to stand factors such as soil and stocking when regenerating white pine stands.
      PubDate: 2016-11-11
      DOI: 10.3390/f7110269
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 270: Understanding the Fate of Applied Nitrogen in
           Pine Plantations of the Southeastern United States Using 15N Enriched

    • Authors: Jay Raymond, Thomas Fox, Brian Strahm
      First page: 270
      Abstract: This study was conducted to determine the efficacy of using enhanced efficiency fertilizer (EEFs) products compared to urea to improve fertilizer nitrogen use efficiency (FNUE) in forest plantations. All fertilizer treatments were labeled with 15N (0.5 atom percent) and applied to 100 m2 circular plots at 12 loblolly pine stands (Pinus taeda L.) across the southeastern United States. Total fertilizer N recovery for fertilizer treatments was determined by sampling all primary ecosystem components and using a mass balance calculation. Significantly more fertilizer N was recovered for all EEFs compared to urea, but there were generally no differences among EEFs. The total fertilizer N ecosystem recovery ranged from 81.9% to 84.2% for EEFs compared to 65.2% for urea. The largest amount of fertilizer N recovered for all treatments was in the loblolly pine trees (EEFs: 38.5%–49.9%, urea: 34.8%) and soil (EEFs: 30.6%–38.8%, urea: 28.4%). This research indicates that a greater ecosystem fertilizer N recovery for EEFs compared to urea in southeastern pine plantations can potentially lead to increased FNUE in these systems.
      PubDate: 2016-11-11
      DOI: 10.3390/f7110270
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 271: Modeling the Boundaries of Plant Ecotones of
           Mountain Ecosystems

    • Authors: Yulia Ivanova, Vlad Soukhovolsky
      First page: 271
      Abstract: The ecological second-order phase transition model has been used to describe height-dependent changes in the species composition of mountain forest ecosystems. Forest inventory data on the distribution of various tree species in the Sayan Mountains (south Middle Siberia) are in good agreement with the model proposed in this study. The model was used to estimate critical heights for different altitudinal belts of vegetation, determine the boundaries and extents of ecotones between different vegetation belts, and reveal differences in the ecotone boundaries between the north- and south-facing transects. An additional model is proposed to describe ecotone boundary shifts caused by climate change.
      PubDate: 2016-11-12
      DOI: 10.3390/f7110271
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 272: Optimization Forest Thinning Measures for
           Carbon Budget in a Mixed Pine-Oak Stand of the Qingling Mountains, China:
           A Case Study

    • Authors: Lin Hou, Zhe Li, Chunlin Luo, Longlong Bai, Ningning Dong
      First page: 272
      Abstract: Forest thinning is a silviculture treatment for sustainable forest management. It may promote growth of the remaining individuals by decreasing stand density, reducing competition, and increasing light and nutrient availability to increase carbon sequestration in the forest ecosystem. However, the action also increases carbon loss simultaneously by reducing carbon and other nutrient inputs as well as exacerbating soil CO2 efflux. To achieve a maximum forest carbon budget, the central composite design with two independent variables (thinning intensity and thinning residual removal rate) was explored in a natural pine-oak mixed stand in the Qinling Mountains, China. The net primary productivity of living trees was estimated and soil CO2 efflux was stimulated by the Yasso07 model. Based on two years observation, the preliminary results indicated the following. Evidently chemical compounds of the litter of the tree species affected soil CO2 efflux stimulation. The thinning residual removal rate had a larger effect than thinning intensity on the net ecosystem productivity. When the selective thinning intensity and residual removal rate was 12.59% and 66.62% concurrently, the net ecosystem productivity reached its maximum 53.93 t·ha−1·year−1. The lower thinning intensity and higher thinning residual removal rated benefited the net ecosystem productivity.
      PubDate: 2016-11-12
      DOI: 10.3390/f7110272
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 273: Fire Scenarios in Spain: A Territorial
           Approach to Proactive Fire Management in the Context of Global Change

    • Authors: Cristina Montiel Molina, Luis Galiana-Martín
      First page: 273
      Abstract: Humans and fire form a coupled and co-evolving natural-human system in Mediterranean-climate ecosystems. In this context, recent trends in landscape change, such as urban sprawl or the abandoning of agricultural and forest land management in line with new models of economic development and lifestyles, are leading to new fire scenarios. A fire scenario refers to the contextual factors of a fire regime, i.e., the environmental, socio-economic and policy drivers of wildfire initiation and propagation on different spatial and temporal scales. This is basically a landscape concept linking territorial dynamics (related to ecosystem evolution and settlement patterns) with a fire regime (ignition causes; spread patterns; fire frequency, severity, extent and seasonality). The aim of this article is to identify and characterize these land-based fire scenarios in Spain on a national and regional scale, using a GIS-based methodology to perform a spatial analysis of the area attributes of homogenous fire spread patterns. To do this, the main variables considered are: land use/land cover, fuel load and recent fire history. The final objective is to reduce territorial vulnerability to forest wildfires and facilitate the adaptation of fire policies and land management systems to current challenges of preparedness and uncertainty management.
      PubDate: 2016-11-12
      DOI: 10.3390/f7110273
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 274: Haploids in Conifer Species: Characterization
           and Chromosomal Integrity of a Maritime Pine Cell Line

    • Authors: José Cabezas, Marian Morcillo, María Vélez, Luis Díaz, Juan Segura, María Cervera, Isabel Arrillaga
      First page: 274
      Abstract: Haploids are a valuable tool for genomic studies in higher plants, especially those with huge genome size and long juvenile periods, such as conifers. In these species, megagametophyte cultures have been widely used to obtain haploid callus and somatic embryogenic lines. One of the main problems associated with tissue culture is the potential genetic instability of the regenerants. Because of this, chromosomal stability of the callus and/or somatic embryos should also be assessed. To this end, chromosome counting, flow cytometry and genotyping using microsatellites have been reported. Here, we present an overview of the work done in conifers, with special emphasis on the production of a haploid cell line in maritime pine (Pinus pinaster L.) and the use of a set of molecular markers, which includes Single Nucleotide Polymorphisms (SNPs) and microsatellites or Single Sequence Repeats (SSRs), to validate chromosomal integrity confirming the presence of all chromosomic arms.
      PubDate: 2016-11-12
      DOI: 10.3390/f7110274
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 275: Wood or Laminate?—Psychological Research of
           Customer Expectations

    • Authors: Paul Jiménez, Anita Dunkl, Kerstin Eibel, Elisabeth Denk, Vincent Grote, Christina Kelz, Maximilian Moser
      First page: 275
      Abstract: Wood is generally associated with being practical, aesthetic and economy-friendly. Using wood in interior settings also can be based on psychological expectations and assumptions, as wood is attributed as warmer, more homely, more relaxing and more inviting. However, when investigating psychological differences, wood is usually compared to carpets, glass, leather, stone, or plastic but is not compared to a visually similar material such as laminate. The aim of this study is to analyze and compare the various psychological characteristics related to wooden and laminate materials in interior settings. The experimental design was a 2 × 2 design (material, sequence) with repeated measures for material. Forty participants were asked to evaluate a framed piece of wood floor and a framed piece of laminate floor regarding technical, practical, and psychological aspects. Further, three questions about one’s purchase decision were asked. The results show that the wooden floor was evaluated significantly better than the laminate floor regarding “materials and processing”, “atmosphere”, and “values and symbolic functions”. For the criterion “health”, a tendency in favor of wood could be found. In addition, the participants would more likely recommend and purchase wooden products and also accept more deficiencies in wooden products.
      PubDate: 2016-11-12
      DOI: 10.3390/f7110275
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 276: Effect of Tree Spacing on Tree Level Volume
           Growth, Morphology, and Wood Properties in a 25-Year-Old Pinus banksiana
           Plantation in the Boreal Forest of Quebec

    • Authors: François Hébert, Cornelia Krause, Pierre-Yves Plourde, Alexis Achim, Guy Prégent, Jean Ménétrier
      First page: 276
      Abstract: The number of planted trees per hectare influences individual volume growth, which in turn can affect wood properties. The objective of this study was to assess the effect of six different plantation spacings of jack pine (Pinus banksiana Lamb.) 25 years following planting on tree growth, morphology, and wood properties. Stem analyses were performed to calculate annual and cumulative diameter, height, and volume growth. For morphological and wood property measurements several parameters were analyzed: diameter of the largest branch, live crown ratio, wood density, and the moduli of elasticity and rupture on small clear samples. The highest volume growth for individual trees was obtained in the 1111 trees/ha plantation, while the lowest was in the 4444 trees/ha plantation. Wood density and the moduli of elasticity and rupture did not change significantly between the six plantation spacings, but the largest branch diameter was significantly higher in the 1111 trees/ha (3.26 cm mean diameter) compared with the 4444 trees/ha spacing (2.03 cm mean diameter). Based on this study, a wide range of spacing induced little negative effect on the measured wood properties, except for the size of knots. Increasing the initial spacing of jack pine plantations appears to be a good choice if producing large, fast-growing stems is the primary goal, but lumber mechanical and visual properties could be decreased due to the larger branch diameter.
      PubDate: 2016-11-12
      DOI: 10.3390/f7110276
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 277: Resource Utilization by Native and Invasive
           Earthworms and Their Effects on Soil Carbon and Nitrogen Dynamics in
           Puerto Rican Soils

    • Authors: Ching-Yu Huang, Grizelle González, Paul Hendrix
      First page: 277
      Abstract: Resource utilization by earthworms affects soil C and N dynamics and further colonization of invasive earthworms. By applying 13C-labeled Tabebuia heterophylla leaves and 15N-labeled Andropogon glomeratus grass, we investigated resource utilization by three earthworm species (invasive endogeic Pontoscolex corethrurus, native anecic Estherella sp, and native endogeic Onychochaeta borincana) and their effects on soil C and N dynamics in Puerto Rican soils in a 22-day laboratory experiment. Changes of 13C/C and 15N/N in soils, earthworms, and microbial populations were analyzed to evaluate resource utilization by earthworms and their influences on C and N dynamics. Estherella spp. utilized the 13C-labeled litter; however, its utilization on the 13C-labeled litter reduced when cultivated with P. corethrurus and O. borincana. Both P. corethrurus and O. borincana utilized the 13C-labeled litter and 15C-labeled grass roots and root exudates. Pontoscolex corethrurus facilitated soil respiration by stimulating 13C-labeled microbial activity; however, this effect was suppressed possibly due to the changes in the microbial activities or community when coexisting with O. borincana. Increased soil N mineralization by individual Estherella spp. and O. borincana was reduced in the mixed-species treatments. The rapid population growth of P. corethrurus may increase competition pressure on food resources on the local earthworm community. The relevance of resource availability to the population growth of P. corethrurus and its significance as an invasive species is a topic in need of future research.
      PubDate: 2016-11-15
      DOI: 10.3390/f7110277
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 278: Recent Afforestation in the Iowa River and
           Vorskla River Basins: A Comparative Trends Analysis

    • Authors: Yury Chendev, Jason Hubbart, Edgar Terekhin, Anthony Lupo, Tom Sauer, C. Burras
      First page: 278
      Abstract: Afforestation trends were compared between two continentally-distinct, yet similar ecoregions to characterize similarities or differences in forest advancement due to natural and anthropogenic forcings. Temporal changes in forest cover were analyzed using high resolution aerial and satellite photographs for Southeast Iowa, USA, and satellite photographs for the western Belgorod Oblast, Russia. An increase in forested area was shown to occur over a 44-year period from 1970–2014 in Iowa where afforestation was reflected by the aggregation of smaller forest units. In the Belgorod region the opposite occurred in that there was an increase in the number of smaller forested units. The rate of forest expansion into open grassland areas, previously used as haying lands and pastures, was 14 m decade−1 and 8 m decade−1 in Iowa and the Belgorod Oblast, respectively. Based on current trends, predicted times for complete forest coverage in the study areas was estimated to be 80 years in Iowa and 300 years in the Belgorod Oblast. In both the Iowa and Belgorod Oblast, there was an increase in annual precipitation at the end of the 20th and the beginning of the 21st centuries, thus providing a contributing mechanism to forest advancement in the study regions and implications for future management practices.
      PubDate: 2016-11-15
      DOI: 10.3390/f7110278
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 279: Surface CO2 Exchange Dynamics across a
           Climatic Gradient in McKenzie Valley: Effect of Landforms, Climate and

    • Authors: Natalia Startsev, Jagtar Bhatti, Rachhpal Jassal
      First page: 279
      Abstract: Northern regions are experiencing considerable climate change affecting the state of permafrost, peat accumulation rates, and the large pool of carbon (C) stored in soil, thereby emphasizing the importance of monitoring surface C fluxes in different landform sites along a climate gradient. We studied surface net C exchange (NCE) and ecosystem respiration (ER) across different landforms (upland, peat plateau, collapse scar) in mid-boreal to high subarctic ecoregions in the Mackenzie Valley of northwestern Canada for three years. NCE and ER were measured using automatic CO2 chambers (ADC, Bioscientific LTD., Herts, England), and soil respiration (SR) was measured with solid state infrared CO2 sensors (Carbocaps, Vaisala, Vantaa, Finland) using the concentration gradient technique. Both NCE and ER were primarily controlled by soil temperature in the upper horizons. In upland forest locations, ER varied from 583 to 214 g C·m−2·year−1 from mid-boreal to high subarctic zones, respectively. For the bog and peat plateau areas, ER was less than half that at the upland locations. Of SR, nearly 75% was generated in the upper 5 cm layer composed of live bryophytes and actively decomposing fibric material. Our results suggest that for the upland and bog locations, ER significantly exceeded NCE. Bryophyte NCE was greatest in continuously waterlogged collapsed areas and was negligible in other locations. Overall, upland forest sites were sources of CO2 (from 64 g·C·m−2·year−1 in the high subarctic to 588 g C·m−2·year−1 in mid-boreal zone); collapsed areas were sinks of C, especially in high subarctic (from 27 g·C·m−2 year−1 in mid-boreal to 86 g·C·m−2·year−1 in high subarctic) and peat plateaus were minor sources (from 153 g·C·m−2·year−1 in mid-boreal to 6 g·C·m−2·year−1 in high subarctic). The results are important in understanding how different landforms are responding to climate change and would be useful in modeling the effect of future climate change on the soil C balance in the northern regions.
      PubDate: 2016-11-15
      DOI: 10.3390/f7110279
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 280: Morphological Characteristics and Water-Use
           Efficiency of Siberian Elm Trees (Ulmus pumila L.) within Arid Regions of
           Northeast Asia

    • Authors: Go Park, Don Lee, Ki Kim, Nyam-Osor Batkhuu, Jamsran Tsogtbaatar, Jiao-Jun Zhu, Yonghuan Jin, Pil Park, Jung Hyun, Hyun Kim
      First page: 280
      Abstract: The Siberian elm (Ulmus pumila L.) is one of the most commonly found tree species in arid areas of northeast Asia. To understand the morphological and physiological characteristics of Siberian elms in arid regions, we analyzed leaves from seven study sites (five arid or semi-arid and two mesic) in China, Mongolia and the Republic of Korea, which covered a wide range of average annual precipitation (232 mm·year−1 to 1304 mm·year−1) under various aridity indexes (AI) and four different microenvironments: sand dune, steppe, riverside and forest. The traits of Siberian elms varied widely along different annual precipitation (P) and AI gradients. Tree height (H), leaf size (LS) and stomatal area per unit leaf area (AS/AL) decreased with increasing AI, whereas leaf mass per unit leaf area (LMA) and water-use efficiency (WUE) increased significantly. In addition, trees at the five arid sites showed significant differences in LS, LMA and AS/AL but not in H and WUE. Thus, our study indicated that indigenous Siberian elm trees in arid areas have substantially altered their morphological and physiological characteristics to avoid heat stress and increase water conservation in comparison to mesic areas. However, their changes differed depending on the surrounding microenvironment even in arid areas. Trees in sand dunes had a smaller LS, higher LMA, thicker leaf cuticle layer and higher stomatal density and AS than those in steppes and near a riverside.
      PubDate: 2016-11-17
      DOI: 10.3390/f7110280
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 281: Deforestation Effects on Soil Erosion in the
           Lake Kivu Basin, D.R. Congo-Rwanda

    • Authors: Fidele Karamage, Hua Shao, Xi Chen, Felix Ndayisaba, Lamek Nahayo, Alphonse Kayiranga, James Omifolaji, Tong Liu, Chi Zhang
      First page: 281
      Abstract: Deforestation and natural grassland conversion to agricultural land use constitute a major threat to soil and water conservation. This study aimed at assessing the status of land cover and land use (LCLU) in the Lake Kivu basin, and its related impacts in terms of soil erosion by water using the Universal Soil Erosion Equation (USLE) model. The results indicated that the Lake Kivu basin is exposed to soil erosion risk with a mean annual rate of 30 t·ha−1, and only 33% of the total non-water area is associated with a tolerable soil loss (≤10 t·ha−1·year−1). Due to both natural factors (abundant tropical precipitation and steep slopes) and anthropogenic activities without prior appropriate conservation practices, all land-use types—namely settlement, cropland, forestland, and grassland—are exposed to a severe mean erosion rate of 41 t·ha−1·year−1, 31 t·ha−1·year−1, 28 t·ha−1·year−1, and 20 t·ha−1·year−1, respectively. The cropland that occupied 74% of the non-water area in 2015 was the major contributor (75%) to the total annual soil loss in the Lake Kivu basin. This study showed that conservation practices in the cropland cells would result in a mean erosion rate of 7 t·ha−1·year−1, 18 t·ha−1·year−1, and 35 t·ha−1·year−1 for terracing, strip-cropping, and contouring, respectively. The adoption of terracing would be the best conservation practice, among others, that could reduce soil erosion in cropland areas up to about 23%. The erosion risk minimization in forests and grasslands implies an increase in overstorey canopy and understorey vegetation, and control of human activities such as fires, mining, soil compaction from domestic animals grazing, and so on. Soil erosion control in settled areas suggests, among other things, the revegetation of construction sites, establishment of outlet channels, rainfall water harvesting systems, and pervious paving block with grass.
      PubDate: 2016-11-17
      DOI: 10.3390/f7110281
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 282: Carbon and Nitrogen Pools and Fluxes in
           Adjacent Mature Norway Spruce and European Beech Forests

    • Authors: Filip Oulehle, Michal Růžek, Karolina Tahovská, Jiří Bárta, Oldřich Myška
      First page: 282
      Abstract: We compared two adjacent mature forest ecosystem types (spruce vs. beech) to unravel the fate of assimilated carbon (C) and the cycling of organic and inorganic nitrogen (N) without the risk of the confounding influences of climatic and site differences when comparing different sites. The stock of C in biomass was higher (258 t·ha−1) in the older (150 years) beech stand compared to the younger (80 years) planted spruce stand (192 t·ha−1), whereas N biomass pools were comparable (1450 kg·ha−1). Significantly higher C and N soil pools were measured in the beech stand, both in forest floor and mineral soil. Cumulative annual CO2 soil efflux was similar among stands, i.e., 9.87 t·ha−1·year−1 of C in the spruce stand and 9.01 t·ha−1·year−1 in the beech stand. Soil temperature explained 78% (Q10 = 3.7) and 72% (Q10 = 4.2) of variability in CO2 soil efflux in the spruce and beech stand, respectively. However, the rather tight N cycle in the spruce stand prevented inorganic N losses, whereas losses were higher in the beech stand and were dominated by nitrate in the mineral soil. Our results highlighted the long-term consequences of forest management on C and N cycling.
      PubDate: 2016-11-17
      DOI: 10.3390/f7110282
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 283: Back to the Future: The Persistence of Horse

    • Authors: David Bray, Elvira Duran, Javier Hernández-Salas, Concepción Luján-Alvarez, Miguel Olivas-García, Iván Grijalva-Martínez
      First page: 283
      Abstract: Horse skidding for extracting logwood is characterized as a niche activity in small-scale forestry, limited to small tracts and low volumes, where environmental impacts and aesthetics are concerned, and to operations with no wood-processing facilities. This article documents and analyzes the widespread persistence, current magnitude, and multiple advantages of horse skidding in large-scale industrial community forest enterprises in Chihuahua, Mexico. We extracted data from the logging permit files of 59 communities in the Sierra Tarahumara and conducted semi-structured interviews with community leaders and foresters in 18 communities, 17 random selections, and one purposefully selected case. There are nine communities that can be considered large-scale. Six of them use animal traction for 20%–100% of their volume. All have sawmills integrated with their operations. This includes the El Largo community with a ten-year volume of 3,169,019 m3 extracted from 123,810 ha entirely with horses. Respondents to the interviews report that horse skidding is more cost-effective than mechanized skidding, generates more employment, and has less impact on forests due to reduced carbon emissions. The widespread use of animal traction in large-scale industrial community forestry in Chihuahua demonstrates that horse skidding is not only a niche activity in small-scale forestry. Our data is preliminary, but we suggest that it highlights a need for further assessments of whether animal traction should be part of future efforts towards reduced impact, lower carbon emissions, and socially and economically just forest management.
      PubDate: 2016-11-16
      DOI: 10.3390/f7110283
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 284: Spatial Pattern of the Mitochondrial and
           Chloroplast Genetic Variation in Poland as a Result of the Migration of
           Abies alba Mill. from Different Glacial Refugia

    • Authors: Monika Litkowiec, Andrzej Lewandowski, Grzegorz Rączka
      First page: 284
      Abstract: Currently, the information on the gene pool of silver fir (Abies alba Mill.) at the northeastern edge of its distribution in Poland is scarce and insufficient. Using the advantage provided by markers with different modes of inheritance, a hypothesis that gene flow via both seeds and pollen contributed to the genetic structure across the entire analyzed region was investigated. The geographic distribution of maternally inherited mitochondrial DNA (mtDNA, nad5-4) and paternally inherited chloroplast DNA (cpDNA, psbC) variation was studied in 81 Polish populations and three reference populations from Ukraine and Romania. The spatial pattern of mtDNA haplotypes (dispersed via seeds) indicated that the Apennine Peninsula was the only maternal glacial refugium for the entire territory of Poland and also the Ukraine no 1 population, whereas the other two populations—Ukraine no 2 and Romania—had the haplotype representing the Balkan origin. By contrast, the cpDNA haplotypes (dispersed via pollen) from all studied Polish and reference populations showed that A. alba colonized the current natural range from two genetically distinct glacial refugia located on the Apennine and Balkan peninsulas. The occurrence of cpDNA haplotypes varied among the studied populations. Additionally, statistical analyses were used to infer the genetic structure of examined populations. Two distinct groups of A. alba populations were identified showing the postglacial geographic distribution of haplotypes of both mtDNA and cpDNA. A. alba is an important ecological and economic component of forest ecosystems in Europe. An understanding of the Holocene history of this species is relevant for planning sustainable forest management, and acquired data can contribute to strategies of conservation and restoration.
      PubDate: 2016-11-17
      DOI: 10.3390/f7110284
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 285: Assessment of Forest Management in Protected
           Areas Based on Multidisciplinary Research

    • Authors: Ivo Machar, Jaroslav Simon, Klement Rejsek, Vilem Pechanec, Jan Brus, Helena Kilianova
      First page: 285
      Abstract: The remnants of primeval Norway spruce forests in the European temperate zone are crucial for maintaining forest biodiversity in high mountain landscapes. This paper presents results of a multidisciplinary research and evaluation project on the management practices for mountain spruce forests in the Natura 2000 site (National Nature Reserve Serak-Keprnik in the Hruby Jesenik Mountains, the Czech Republic). Results are based on combining research on the historical development of the forest ecosystem and predictions of future dynamics using a forest growth simulation model. The presented results show that a non-intervention management strategy for mountain spruce forest in the next 50 years complies with the Natura 2000 requirement to maintain the existing character of the forest habitat. Thus, the results indicate that the current management plan for the spruce forests does not require significant corrections in the context of its conservation goals (i.e., maintaining biodiversity and current character of the forest ecosystem dominated by Norway spruce). The results of this study suggest that combining the knowledge of historical development with forest inventory data using forest growth simulation represents a suitable support tool for the assessment of management practices for forest habitats in protected areas.
      PubDate: 2016-11-16
      DOI: 10.3390/f7110285
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 286: Perceived Acceptability of Implementing
           Marker-Assisted Selection in the Forests of British Columbia

    • Authors: Chelsea Nilausen, Nancy Gélinas, Gary Bull
      First page: 286
      Abstract: The forest sector in British Columbia (BC) has faced a number of challenges over the past decade. In response to some of those challenges, the government has invested in forest genomic tools. Marker-assisted selection (MAS) is a biotechnological tool that flags desired traits on the genome. This tool may assist tree breeders with the early selection of preferred genotypes, reducing the breeding cycle and more accurately and efficiently selecting for improved qualities. However, there is a poor understanding of the perceived acceptability of implementing MAS. Semi-structured interviews and a questionnaire were employed across participants categorized into four groups. It was found that government and industry participants held positive perceptions towards MAS, supporting its use and continued research in BC, and identifying its benefits in forest regeneration and to tree breeders. Environmental non-governmental organizations (ENGOs) and First Nations attitudes lay between neutral and negative. Concerns were most strongly focused on environmental impacts, ecosystem degradation, and reduced genetic diversity, while identified benefits were specific to tree breeders and improved tree resiliency. It was concluded that before MAS can be successfully implemented, an appropriate setting must first be established through improved knowledge of biotechnology and its applications, well-defined policies, and strengthened engagement and consultation with First Nations.
      PubDate: 2016-11-18
      DOI: 10.3390/f7110286
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 287: Biomass Accumulation and Net Primary
           Production during the Early Stage of Secondary Succession after a Severe
           Forest Disturbance in Northern Japan

    • Authors: Tomotsugu Yazaki, Takashi Hirano, Tomohito Sano
      First page: 287
      Abstract: Quantitative evaluations of biomass accumulation after disturbances in forests are crucially important for elucidating and predicting forest carbon dynamics in order to understand the carbon sink/source activities. During early secondary succession, understory vegetation often affects sapling growth. However, reports on biomass recovery in naturally-regenerating sites are limited in Japan. Therefore, we traced annual or biennial changes in plant species, biomass, and net primary production (NPP) in a naturally regenerating site in Japan after windthrow and salvage-logging plantation for nine years. The catastrophic disturbance depleted the aboveground biomass (AGB) from 90.6 to 2.7 Mg·ha−1, changing understory dominant species from Dryopteris spp. to Rubus idaeus. The mean understory AGB recovered to 4.7 Mg·ha−1 in seven years with the dominant species changing to invasive Solidago gigantea. Subsequently, patches of deciduous trees (mainly Betula spp.) recovered whereas the understory AGB decreased. Mean understory NPP increased to 272 g·C·m−2·year−1 within seven years after the disturbance, but decreased thereafter to 189 g·C·m−2·year−1. Total NPP stagnated despite increasing overstory NPP. The biomass accumulation is similar to that of naturally regenerating sites without increase of trees in boreal and temperate regions. Dense ground vegetation and low water and nutrient availability of the soil in the study site restrict the recovery of canopy-forming trees and eventually influence the biomass accumulation.
      PubDate: 2016-11-18
      DOI: 10.3390/f7110287
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 288: A Forest Growth Model for the Natural
           Broadleaved Forests in Northeastern Korea

    • Authors: Jiseon Choi, Hyunjin An
      First page: 288
      Abstract: While a large sum of timber stock in private forests, especially broadleaved forests, has been ignored by their owners, a rising global concern about climate change and ecosystems has led to a renewed interest in natural broadleaved forest management strategies. This study establishes the forest growth model for the natural broadleaved forest of Gangwon-do based on the matrix model developed by Buongiorno and Michie. The matrix model by Buongiorno and Michie has been widely applied to study forest population dynamics, especially for uneven-aged forests. To develop an existing matrix model, our approach applies transitional probabilities of forest stands which are calibrated using National Forest Inventory data. Both long and short-term predicted simulation results show that the predicted average tree density and diameter distribution from our model are very close to the stand density and diameter distribution from observed data. Although the model simplifies reality, the results from our study confirm that our models are valid enough to predict the average stand status of the broadleaved forests in Gangwon-do.
      PubDate: 2016-11-23
      DOI: 10.3390/f7110288
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 289: Oak Group Planting Produces a Higher Number of
           Future Crop Trees, with Better Spatial Distribution than Row Planting

    • Authors: Georgios Skiadaresis, Somidh Saha, Jürgen Bauhus
      First page: 289
      Abstract: Recent studies have reported superior tree quality and comparable tree growth of oaks planted in group compared with row planting. However, a comparative assessment of the potential future crop trees (PFCTs) between group and row planting is still lacking. Here, we compared the density and tree quality of planted oaks and other naturally regenerated trees between group and row planting. We assessed whether the distribution of PFCTs fulfills the goal of maintaining a spatially homogenous distribution of such crop trees at the stand level by geospatial analysis. We selected 10 group and row planting stands that were either 14 to 15 or 21 to 22 years old. Tree density in group plantings was significantly higher than in row plantings. Stand basal area was higher in row planting in younger stands but comparable to group planting in older stands. The proportion of trees with straight stems and monopodial crowns was higher in groups than in rows. The density and species’ richness of the PFCTs was significantly higher but the number of oak PFCTs was lower in group than in row plantings. In group plantings, naturally regenerated PFCTs contributed to 43% of total PFCTs, but to only 19% in row plantings. Also, the spatial distribution of PFCTs in group plantings was more uniform than in row plantings. Uniform and homogeneous distribution of the PFCTs in group planting stands can facilitate design and conduct of tending operations. Thus, the group planting technique offers not only cost savings in the establishment phase but also additional benefits, including spreading of risks through increased tree species diversity.
      PubDate: 2016-11-22
      DOI: 10.3390/f7110289
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 290: Nutrient Resorption and Phenolics
           Concentration Associated with Leaf Senescence of the Subtropical Mangrove
           Aegiceras corniculatum: Implications for Nutrient Conservation

    • Authors: Hui Chen, Benbo Xu, Shudong Wei, Lihua Zhang, Haichao Zhou, Yiming Lin
      First page: 290
      Abstract: Aegiceras corniculatum (L.) Blanco, a mangrove shrub species in the Myrsine family, often grows at the seaward edge of the mangrove zone in China. In the present study, seasonal dynamics of nutrient resorption and phenolics concentration associated with leaf senescence of A. corniculatum were investigated in order to evaluate its possible nutrient conservation strategies in the subtropical Zhangjiang river estuary. It was found that the nitrogen (N) and phosphorus (P) concentrations in mature leaves showed similar seasonal changes with the highest concentrations in winter and the lowest in summer, and were significantly higher than those in senescent leaves. The N:P ratios of mature leaves through the year were found to be less than 14, indicating that the A. corniculatum forest was N-limited. The nitrogen resorption efficiency (NRE) was higher than phosphorus resorption efficiency (PRE), and N resorption was complete. In addition, A. corniculatum leaves contained high total phenolics (TPs) and total condensed tannin (TCT) levels (both above 20%). TPs concentrations in mature and senescent leaves were all inversely related to their N or P concentrations. TPs:N and TCT:N ratios in senescent leaves were significantly higher than those in mature leaves. The obtained results suggested that high NRE during leaf senescence and high TPs:N and TCT:N ratios in senescent leaves might be important nutrient conservation strategies for the mangrove shrub A. corniculatum forest growing in N-limited conditions.
      PubDate: 2016-11-22
      DOI: 10.3390/f7110290
      Issue No: Vol. 7, No. 11 (2016)
  • Forests, Vol. 7, Pages 210: Environmental Factors Effect on Stem Radial
           Variations of Picea crassifolia in Qilian Mountains, Northwestern China

    • Authors: Wenbin Wang, Fen Zhang, Liming Yuan, Qingtao Wang, Kai Zheng, Chuanyan Zhao
      First page: 210
      Abstract: Picea crassifolia Komarov (Qinghai spruce) is an endemic tree species in China and is widespread in the Qilian Mountains, in northwestern China. High temporal resolution changes of Qinghai spruce tree stem growth remain poorly investigated and the relationships between the species growth and climate are still not completely understood. In this study, we assessed the daily and seasonal stem radial variations, and analyzed the relationships between stem radial increment of Qinghai spruce and environmental factors during the main growing period (June–August). We have found that the stem radial variations of Qinghai spruce can be divided into three phases according to the air temperature and that Qinghai spruce has two diurnal cycle patterns. The main growing period of Qinghai spruce is 30 May–31 August according to micro-core measurements, in conformity with the daily mean air temperature keeping above 5 °C. Precipitation and relative humidity have positive effects on the growth of Qinghai spruce, and we develop a multiple linear regression model that can explain 63% of the stem radial increment over the main growing period.
      PubDate: 2016-09-23
      DOI: 10.3390/f7100210
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 211: Fire Regime along Latitudinal Gradients of
           Continuous to Discontinuous Coniferous Boreal Forests in Eastern Canada

    • Authors: Jeanne Portier, Sylvie Gauthier, Alain Leduc, Dominique Arseneault, Yves Bergeron
      First page: 211
      Abstract: Fire is the main disturbance in North American coniferous boreal forests. In Northern Quebec, Canada, where forest management is not allowed, the landscape is gradually constituted of more opened lichen woodlands. Those forests are discontinuous and show a low regeneration potential resulting from the cumulative effects of harsh climatic conditions and very short fire intervals. In a climate change context, and because the forest industry is interested in opening new territories to forest management in the north, it is crucial to better understand how and why fire risk varies from the north to the south at the transition between the discontinuous and continuous boreal forest. We used time-since-fire (TSF) data from fire archives as well as a broad field campaign in Quebec’s coniferous boreal forests along four north-south transects in order to reconstruct the fire history of the past 150 to 300 years. We performed survival analyses in each transect in order to (1) determine if climate influences the fire risk along the latitudinal gradient; (2) fractionate the transects into different fire risk zones; and (3) quantify the fire cycle—defined as the time required to burn an area equivalent to the size of the study area—of each zone and compare its estimated value with current fire activity. Results suggest that drought conditions are moderately to highly responsible for the increasing fire risk from south to north in the three westernmost transects. No climate influence was observed in the last one, possibly because of its complex physical environment. Fire cycles are shortening from south to north, and from east to west. Limits between high and low fire risk zones are consistent with the limit between discontinuous and continuous forests, established based on recent fire activity. Compared to the last 40 years, fire cycles of the last 150–300 years are shorter. Our results suggest that as drought episodes are expected to become more frequent in the future, fire activity might increase significantly, possibly leading to greater openings within forests. However, if fire activity increases and yet remains within the range of variability of the last 150–300 years, the limit between open and closed forests should stay relatively stable.
      PubDate: 2016-09-24
      DOI: 10.3390/f7100211
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 212: Governance Values in the Climate Change

    • Authors: Timothy Cadman, Tek Maraseni, Hugh Breakey, Federico López-Casero, Hwan Ma
      First page: 212
      Abstract: This paper presents the results of two national-level studies of REDD+ governance values in Nepal and Papua New Guinea (PNG), using a hierarchical framework of principles, criteria, and indicators (PC&I), with evaluation at the indicator level. The research was conducted by means of an online survey to determine general perspectives on the governance quality of REDD+, as well as stakeholder workshops, in which participants were asked to rank indicators on the basis of perceived national significance. In the online survey, respondents in both countries identified inclusiveness and resources as the highest and lowest scoring governance values, while inclusiveness, resources, accountability, and transparency, were given priority, although their relative importance differed between countries given national circumstances. The reasons for the commonalities and differences of perceptions between these countries are discussed. The findings suggest that while a generic set of governance values may be usefully applied for determining the institutional legitimacy of REDD+, their relative importance is different. This leads to the conclusion that it may not be appropriate to use a simplified approach to REDD+ governance, focusing for example on safeguards, given different national priorities and contexts.
      PubDate: 2016-09-23
      DOI: 10.3390/f7100212
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 213: The Alleviation of Nutrient Deficiency
           Symptoms in Changbai Larch (Larix olgensis) Seedlings by the Application
           of Exogenous Organic Acids

    • Authors: Jinfeng Song, Daniel Markewitz, Yong Liu, Xingping Liu, Xiaoyang Cui
      First page: 213
      Abstract: Exogenous organic acids are beneficial in protecting plants from the stress of heavy metal toxins (e.g., Pb) in soils. This work focuses on the potential role of organic acids in protecting Changbai larch (Larix olgensis) seedlings from the stress of growing in nutrient deficient soil. The seedlings were planted in a nutrient rich or deficient soil (A1 horizon of a Haplic Cambisol without organic acid as the nutrient rich control, or fully-mixed A1 + B horizons in a proportion of 1:2 as deficient) in pots in a greenhouse. In A1 + B horizons the seedlings were treated daily with concentrations of oxalic or citric acid (OA or CA) at a rate approximately equivalent to 0, 0.04, 0.2, 1.0, or 2.0 mmol·kg−1 of soil for 10, 20, and 30 days. Nutrient deficiency stressed the seedlings as indicated by lipid peroxidation and malondialdehyde (MDA) content in leaves significantly increasing, and superoxide dismutase (SOD) activities, proline, photosynthetic pigment contents, and chlorophyll fluorescence (Fv/Fm) decreasing. The stress increased in controls over the application periods. When nutrient deficient plants were exposed to an organic acid (especially 5.0 or 10.0 mmol·L−1 for 20 days), the stress as indicated by the physiological parameters was reversed, and survival rate of seedlings, and biomass of root, stem, and leaf significantly increased; CA was more effective than OA. The results demonstrate that exogenous organic acids alleviate nutrient deficiency-induced oxidative injuries and improve the tolerance of L. olgensis seedlings to nutrient deficiency.
      PubDate: 2016-09-26
      DOI: 10.3390/f7100213
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 214: Loblolly Pine Productivity and Water Relations
           in Response to Throughfall Reduction and Fertilizer Application on a
           Poorly Drained Site in Northern Florida

    • Authors: Maxwell Wightman, Timothy Martin, Carlos Gonzalez-Benecke, Eric Jokela, Wendell Cropper, Eric Ward
      First page: 214
      Abstract: Loblolly pine (Pinus taeda L.) forests are of great ecological and economic value in the southeastern United States, where nutrient availability frequently limits productivity. The impact of fertilizer application on the growth and water relations of loblolly pine has been investigated by numerous studies; however, few field experiments have examined the effects of drought. Drought is of particular interest due to the potential for climate change to alter soil water availability. In this study, we investigated the impact of fertilizer application and a 30% reduction in throughfall on loblolly pine productivity, transpiration, hydraulic conductance, and stomatal conductance. The study was installed in a ten-year-old loblolly pine plantation on a somewhat poorly drained site in northern Florida. Throughfall reduction did not impact tree productivity or water relations of the trees. This lack of response was attributed to abundant rainfall and the ability of trees to access the shallow water table at this site. Fertilizer application increased basal area production by 20% and maximum leaf area index by 0.5 m2∙m−2, but it did not affect whole-tree hydraulic conductance or the sensitivity of stomatal conductance to vapor pressure deficit. During the spring, when leaf area and vapor pressure deficit were high, the fertilizer-only treatment increased monthly transpiration by 17% when compared to the control. This relationship, however, was not significant during the rest of the year.
      PubDate: 2016-09-26
      DOI: 10.3390/f7100214
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 215: Effects of Temporal and Interspecific
           Variation of Specific Leaf Area on Leaf Area Index Estimation of Temperate
           Broadleaved Forests in Korea

    • Authors: Boram Kwon, Hyun Kim, Jihyeon Jeon, Myong Yi
      First page: 215
      Abstract: This study investigated the effects of interspecific and temporal variation of specific leaf area (SLA, cm2·g−1) on leaf area index (LAI) estimation for three deciduous broadleaved forests (Gwangneung (GN), Taehwa (TH), and Gariwang (GRW)) in Korea with varying ages and composition of tree species. In fall of 2014, fallen leaves were periodically collected using litter traps and classified by species. LAI was estimated by obtaining SLAs using four calculation methods (A: including both interspecific and temporal variation in SLA; B: species specific mean SLA; C: period-specific mean SLA; and D: overall mean), then multiplying the SLAs by the amount of leaves. SLA varied across different species in all plots, and SLAs of upper canopy species were less than those of lower canopy species. The LAIs calculated using method A, the reference method, were GN 6.09, TH 5.42, and GRW 4.33. LAIs calculated using method B showed a difference of up to 3% from the LAI of method A, but LAIs calculated using methods C and D were overestimated. Therefore, species specific SLA must be considered for precise LAI estimation for broadleaved forests that include multiple species.
      PubDate: 2016-09-28
      DOI: 10.3390/f7100215
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 216: Spatial Heterogeneity in Tree Diversity and
           Forest Structure of Evergreen Broadleaf Forests in Southern China along an
           Altitudinal Gradient

    • Authors: Wei Cui, Xiao-Xian Zheng
      First page: 216
      Abstract: We studied the influence of altitude on the spatial heterogeneity of tree diversity and forest structure in a subtropical evergreen broadleaf forest in southern China. Significant positive correlation was found between tree species diversity, basal area and altitude, but negative correlation between slenderness of trunks and altitude. According to topography, tree species diversity, diameter at breast height, height and basal area increased from ridges to valleys, while slenderness and stem density did not differ significantly with topography. Redundancy analysis (RDA) was employed to clarify relationships between tree species diversity and environmental factors (topography and soil water holding capacity). Topography and water conditions jointly explained 57.8% of the diversity variation. Tree species diversity was significantly correlated with altitude, slope and bulk density (Monte Carlo permutation test with 999 permutations, p < 0.05). A positive relationship existed between altitude, soil non-capillary porosity and diversity, while slope, aspect and soil water content were the opposite. Our results show that soil water holding capacity has a positive effect on maintaining species diversity. When comparing with topographic factors—the main driving forces affecting the pattern of tree species diversity—the effect of soil water holding capacity was weak.
      PubDate: 2016-09-30
      DOI: 10.3390/f7100216
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 217: Forest Management Influences Aboveground
           Carbon and Tree Species Diversity in Myanmar’s Mixed Deciduous Forests

    • Authors: Kyaw Sein Win Tun, Julian Di Stefano, Liubov Volkova
      First page: 217
      Abstract: Declines in the global extent and condition of tropical forests have reduced carbon storage potential and caused biodiversity loss. However, the magnitude of these problems within individual countries may depend on the extent of the reserved forest estate, and the particular rules put in place to manage resource use in these areas. To test this hypothesis, aboveground carbon stocks and indices of tree diversity were derived for two reserved (highly regulated) sites and a protected public (less regulated) site in the mixed deciduous forests of Myanmar. Aboveground tree carbon stocks were around three times higher in the reserved forests than in the public forest, a difference driven by the near absence of trees >40 cm DBH at the public forest site. The species composition of large (≥20 cm DBH) trees differed substantially between all three sites. In contrast, the species composition of small (<20 cm DBH) trees differed between the reserved and public forest in the case of one reserved site but not the other. Both species richness and diversity of large (≥20 cm DBH) trees was about five times higher in the reserved forest than in the public forest. This was not the case for small (<20 cm DBH) trees, where estimates of both richness and diversity were similar at all three sites. These findings suggest that both carbon storage potential and large-tree diversity are influenced by forest protection status. This has important implications for national carbon storage estimates as forest protection status is not currently considered as part of the standard carbon accounting procedure.
      PubDate: 2016-09-29
      DOI: 10.3390/f7100217
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 218: Has China’s Natural Forest Protection
           Program Protected Forests?—Heilongjiang’s Experience

    • Authors: Miaoying Shi, Jiaguo Qi, Runsheng Yin
      First page: 218
      Abstract: Since the late 1990s, China has been implementing one of the largest ecological restoration initiatives in not only the country but also the world—the Natural Forest Protection Program (NFPP). An overarching question is how severe the regional deforestation had become before the NFPP was initiated and whether the forest condition in the protected area has significantly improved afterwards. The goal of this study was to assess the land use and land cover changes (LULCC) and the interplays between different land uses in northeast China from the late 1970s to 2013. Classification results were validated through accuracy assessments using the rule-based rationality evaluation scheme and the spatially balanced sampling method. It was found that the regional forestland suffered significant and persistent decline, about 20.4% loss, before 2000 when the NFPP was launched; thereafter, however, the forestland became gradually stabilized and reforestation became more prevalent. Further examination based on extended conversion matrixes revealed that the largest proportional decline came from wetland, instead of forestland, due to farmland encroachment.
      PubDate: 2016-09-29
      DOI: 10.3390/f7100218
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 219: Fire Regime in Marginal Jack Pine Populations
           at Their Southern Limit of Distribution, Riding Mountain National Park,
           Central Canada

    • Authors: Jacques Tardif, Stephen Cornelsen, France Conciatori, Eben Hodgin, Marlow Pellatt
      First page: 219
      Abstract: In central Canada, long fire history reconstructions are rare. In a context where both anthropogenic and climate influences on fire regime have changed, Parks Canada has a mandate to maintain ecological integrity. Here we present a fire history derived from fire-scarred jack pine (Pinus banksiana Lamb.) trees growing at their southern distribution limit in Riding Mountain National Park (RMNP). In Lake Katherine Fire Management Unit (LKFMU), a subregion within the park, fire history was reconstructed from archival records, tree-ring records, and charcoal in lake sediment. From about 1450 to 1850 common era (CE) the fire return intervals varied from 37 to 125 years, according to models. During the period 1864–1930 the study area burned frequently (Weibull Mean Fire Intervals between 2.66 and 5.62 years); this period coincided with the end of First Nations occupation and the start of European settlement. Major recruitment pulses were associated with the stand-replacing 1864 and 1894 fires. This period nevertheless corresponded to a reduction in charcoal accumulation. The current fire-free period in LKFMU (1930–today) coincides with RMNP establishment, exclusion of First Nations land use and increased fire suppression. Charcoal accumulation further decreased during this period. In the absence of fire, jack pine exclusion in LKFMU is foreseeable and the use of prescribed burning is advocated to conserve this protected jack pine ecosystem, at the southern margins of its range, and in the face of potential climate change.
      PubDate: 2016-09-30
      DOI: 10.3390/f7100219
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 220: Using Spatial Optimization to Create Dynamic
           Harvest Blocks from LiDAR-Based Small Interpretation Units

    • Authors: Adrián Pascual, Timo Pukkala, Francisco Rodríguez, Sergio de-Miguel
      First page: 220
      Abstract: Spatial and temporal differences in forest features occur on different scales as forest ecosystems evolve. Due to the increased capacity of remote sensing methods to detect these differences, forest planning may now consider forest compartments as transient units which may change in time and depend on the management objectives. This study presents a methodology for implementing these transient units, referred to as dynamic treatment units (DTU). LiDAR (Light Detecting and Ranging) data and field sample plots were used to estimate forest stand characteristics for 500-m2 pixels and compartments, and a set of models was developed to enable growth simulations. The DTUs were obtained by maximizing a utility function which aimed at maximizing the aggregation of harvest areas and the ending growing stock volume with even-flow cutting targets for three 10-year periods. Remote sensing techniques, modeling, simulation, and spatial optimization were combined with the aim of having an efficient methodology for assigning cutting treatments to forest stands and delineating compact harvest blocks. Pixel-based planning led to more accurate estimation of stand characteristics and more homogeneity inside the delineated harvest blocks while the compartment-based planning resulted in larger and higher area/perimeter ratio.
      PubDate: 2016-09-30
      DOI: 10.3390/f7100220
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 221: Soil CO2 Efflux and Root Productivity in a
           Switchgrass and Loblolly Pine Intercropping System

    • Authors: Paliza Shrestha, John Seiler, Brian Strahm, Eric Sucre, Zakiya Leggett
      First page: 221
      Abstract: Switchgrass intercropped with loblolly pine plantations can provide valuable feedstock for bioenergy production while providing ancillary benefits like controlling competing vegetation and enhancing soil C. Better understanding of the impact of intercropping on pine and switchgrass productivity is required for evaluating the long-term sustainability of this agroforestry system, along with the impacts on soil C dynamics (soil CO2 efflux; RS). RS is the result of root respiration (RA) and heterotrophic respiration (RH), which are used to estimate net C ecosystem exchange. We measured RS in intercropped and monoculture stands of loblolly pine (Pinus taeda L.) and switchgrass (Panicum virgatum L.). The root exclusion core technique was used to estimate RA and RH. The results showed pure switchgrass had significantly higher RS rates (July, August and September), root biomass and length relative to intercropped switchgrass, while there were no significant changes in RS and roots between intercropped and monoculture loblolly pine stands. A significant decrease in switchgrass root productivity in the intercropped stands versus monoculture stands could account for differences in the observed RS. The proportions of RS attributed to RA in the intercropped stand were 31% and 22% in the summer and fall respectively, indicating that the majority of the RS was heterotrophic-driven. Ancillary benefits provided by planting switchgrass between unutilized pine rows can be considered unless the goal is to increase switchgrass production.
      PubDate: 2016-09-30
      DOI: 10.3390/f7100221
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 222: Effects of Topographical and Edaphic Factors
           on Tree Community Structure and Diversity of Subtropical Mountain Forests
           in the Lower Lancang River Basin

    • Authors: Changshun Zhang, Xiaoying Li, Long Chen, Gaodi Xie, Chunlan Liu, Sha Pei
      First page: 222
      Abstract: We investigated community structure and tree species diversity of six subtropical mountain forests in relation to 11 topographical and edaphic factors in Lower Lancang River Basin, Yunnan Province, China, based on a census of all trees with diameter at breast height ≥5 cm in 45 0.06-ha plots. The forests were as follows: a river valley monsoon forest, semi-humid evergreen broad-leaved forest, monsoon evergreen broad-leaved forest, mid-mountain humid evergreen broad-leaved forest, summit mossy dwarf forest, and warm needle-leaved forest. Owing to the variation in microenvironment, forest structure (tree density, mean height, mean diameter at breast height, mean basal area at breast height) and tree diversity indices (the number of species, Margalef richness, Shannon-Wiener diversity, Simpson’s index, and Pielou’s evenness) differed significantly among forest types but did not differ among sites. We recorded a total of 5155 canopy trees belonging to 204 tree species, 104 genera, and 50 families at three sites, and the co-occurrence of tree species between adjacent communities was higher. A clear forest community distribution along an altitudinal gradient suggested that elevation was important in tree species distribution. Ordination identified elevation, slope degree, slope position, soil pH, organic matter, total nitrogen, and available nitrogen as significant explanatory variables of tree species distribution and showed that elevation was more important than the rest of the environmental variables in affecting local woody plant distribution. Understanding relationships between tree species distribution and environmental factors in subtropical mountain forests of the Lower Lancang River Basin would enable us to apply these findings to forest management and vegetation restoration.
      PubDate: 2016-10-01
      DOI: 10.3390/f7100222
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 223: Simulating the Potential Effects of a Changing
           Climate on Black Spruce and Jack Pine Plantation Productivity by Site
           Quality and Locale through Model Adaptation

    • Authors: Peter Newton
      First page: 223
      Abstract: Modifying the stand dynamic functional determinates of structural stand density management models (SSDMMs) through the incorporation of site-specific biophysical height-age equations enabled the simulation of the effects of increasing mean temperature and precipitation during the growing season on black spruce (Picea mariana (Mill.) BSP) and jack pine (Pinus banksiana Lamb.) plantation productivity. The analytical approach consisted of calculating future values of growing season mean temperature and precipitation rates under three emissions scenarios (no change (NC); B1; and A2), spanning three continuous commitment periods (2011–2040; 2041–2070; and 2071–2100), for three geographically separated sites throughout the central portion of the Canadian Boreal Forest Region (north-eastern (Kirkland Lake); north-central (Thunder Bay); and north-western (Dryden) Ontario, Canada), using the Canadian Coupled Global Climate Model (CGCM3) in conjunction with a geographic-referencing climatic surface model. These estimates were entered into the embedded biophysical equations in the SSDMMs in order to forecast emission-scenario-specific developmental patterns of plantations managed under a conventional density management regime by species and site quality (poor-to-medium and good-to-excellent) at each locale; from which stand development rates and associated productivity metrics over 75 year-long rotations were estimated and compared (e.g., mean sizes, volumetric, biomass and carbon yields, end-products, economic worth, stand stability, wood quality indices, and operability status). Simulation results indicated that black spruce plantations situated on both site qualities at the north-western location and on the lower site quality at the north-eastern location were negatively affected from the predicted increased warming and rainfall as evidenced from consequential declines in stand development rates and resultant decreases in rotational mean sizes, biomass yields, recoverable end-product volumes, and economic worth (A2 > B1). Conversely, black spruce plantations situated on both site qualities at the north-central location and on the higher site quality at the north-eastern location were minimally and positively affected under the A2 and B1 scenarios, respectively. Jack pine plantations situated on both site qualities at all three locations were negatively affected as evidentby the reductions in stand development rates and rotational mean sizes, biomass yields, recoverable end-product volumes, and economic worth (A2 > B1). Collectively, these response patterns suggest that stand-level productivity under a changing climate will vary by species, site quality, geographic locale, and emission scenario, potentially resulting in a landscape-level mosaic of both negative and positive productivity impacts in the case of black spruce, and mostly negative impacts in the case of jack pine. As demonstrated, modelling stand-level responses to projected increases in thermal and moisture regimesthrough the modification of existing stand-level forecasting models, and accounting for divergent effects due to species, site quality, and geographic locale differences, is a viable and efficient alternative approach for projecting productivity outcomes arising from anthropogenic-induced changes in growing conditions.
      PubDate: 2016-10-02
      DOI: 10.3390/f7100223
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 224: Fire Regimes of Remnant Pitch Pine Communities
           in the Ridge and Valley Region of Central Pennsylvania, USA

    • Authors: Joseph Marschall, Michael Stambaugh, Benjamin Jones, Richard Guyette, Patrick Brose, Daniel Dey
      First page: 224
      Abstract: Many fire-adapted ecosystems in the northeastern U.S. are converting to fire-intolerant vegetation communities due to fire suppression in the 20th century. Prescribed fire and other vegetation management activities that increase resilience and resistance to global changes are increasingly being implemented, particularly on public lands. For many fire-dependent communities, there is little quantitative data describing historical fire regime attributes such as frequency, severity, and seasonality, or how these varied through time. Where available, fire-scarred live and remnant trees, including stumps and snags, offer valuable insights into historical fire regimes through tree-ring and fire-scar analyses. In this study, we dated fire scars from 66 trees at two sites in the Ridge and Valley Province of the Appalachian Mountains in central Pennsylvania, and described fire frequency, severity, and seasonality from the mid-17th century to 2013. Fires were historically frequent, of low to moderate severity, occurred mostly during the dormant season, and were influenced by aspect and topography. The current extended fire-free interval is unprecedented in the previous 250–300 years at both sites.
      PubDate: 2016-10-02
      DOI: 10.3390/f7100224
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 225: Overstory Tree Mortality in Ponderosa Pine and
           Spruce-Fir Ecosystems Following a Drought in Northern New Mexico

    • Authors: Brian Oswald, Sean Dugan, Randy Balice, Daniel Unger
      First page: 225
      Abstract: Drought-caused tree dieback is an issue around the world as climates change and many areas become dryer and hotter. A drought from 1998–2004 resulted in a significant tree dieback event in many of the wooded areas in portions of the Jemez Mountains and the adjacent Pajarito Plateau in northern New Mexico. The objectives of this study were to evaluate and quantify the differences in tree mortality before and after a recent drought in ponderosa pine and spruce-fir ecosystems, and to assess the effect of mechanical thinning on ponderosa pine mortality. Significant increases in mortality were observed in the unthinned ponderosa pine ecosystem. Mortality varied significantly between species and within size classes. Mechanical thinning of ponderosa pines reduced overstory mortality to non-significant levels. A lack of rainfall, snowfall, and increases in daily minimum temperature contributed most to the mortality. Adaptive management, including the use of thinning activities, appear to moderate the impact of climate change on ponderosa pine forests in this region, increasing the long-term health of the ecosystem. The impact of climate change on the spruce-fir ecosystems may accelerate successional changes.
      PubDate: 2016-10-02
      DOI: 10.3390/f7100225
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 226: Assessment of Red-Edge Position Extraction
           Techniques: A Case Study for Norway Spruce Forests Using HyMap and
           Simulated Sentinel-2 Data

    • Authors: Asa Gholizadeh, Jan Mišurec, Veronika Kopačková, Christian Mielke, Christian Rogass
      First page: 226
      Abstract: Systematic quantification and monitoring of forest biophysical and biochemical variables is required to assess the response of ecosystems to climate change and gain a deeper understanding of the carbon cycle. Red-Edge Position (REP) is a hyperspectrally detectable parameter, which is sensitive to Chlorophyll (Chl) content. In the current study, REP was modelled for Norway spruce Forest canopy Reflectance and Transmittance (FRT) using Radiative Transfer Modelling (RTM) (resampled to HyMap and Sentinel-2 spectral resolution) as well as calculated from the real HyMap and simulated Sentinel-2 image data. Different REP extraction methods (PF, LE, 4PLI and its optimized versions for HyMap and Sentinel-2 spectral resolution) were assessed. The lowest differences in REP values calculated from image-extracted spectra and from the theoretical RTM simulations were found for the 4PLI method including its HyMap and Sentinel-2 optimized versions (4PLIH and 4PLIS). Despite its simplicity, the 4PLI REP extraction technique demonstrated its potential usefulness for estimating canopy chlorophyll (Chl × LAI) content using both airborne hyperspectral (HyMap) data as well as space-borne Sentinel-2 image data.
      PubDate: 2016-10-09
      DOI: 10.3390/f7100226
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 227: Sapflow-Based Stand Transpiration in a
           Semiarid Natural Oak Forest on China’s Loess Plateau

    • Authors: Mei-Jie Yan, Jian-Guo Zhang, Qiu-Yue He, Wei-Yu Shi, Kyoichi Otsuki, Norikazu Yamanaka, Sheng Du
      First page: 227
      Abstract: The semi-arid region of China’s Loess Plateau is characterized by fragile ecosystems and a shortage of water resources. The major natural forest type in this region is the secondary forest with the flora dominated by the Liaodong oak (Quercus liaotungensis Koidz.). To understand its transpiration water use in relation to environmental factors, we applied Granier-type thermal dissipation probes to monitor stem sap flows of 21 sample trees, representing different classes of diameter at breast height in a permanent plot. The stem- and stand-scale transpiration values during the 2008–2010 growing seasons were estimated using measurements of sap flux densities and corresponding sapwood areas. The dominant factors affecting stand-scale transpiration varied with time scales. Daily stand transpiration correlated with daily solar radiation and daytime average vapor pressure deficit. Seasonal and interannual changes in stand transpiration were closely related to leaf area index (LAI) values. No obvious relationship was observed between monthly stand transpiration and soil moisture or precipitation during the period, probably as a result of both the hysteretic effect of precipitation on transpiration, and changes in LAI throughout the growing season. Stand transpiration during the three growing seasons ranged from 75 to 106 mm, representing low to normal values for the semi-arid forest. The proportion of transpiration by oak trees in the stand was stable ranging from 60% to 66% and corresponded to their basal area proportion of approximately 59%. The results suggest that the natural forest consisting mainly of oak trees is in a formal stage of forest development that maintains a normal magnitude of annual water consumption.
      PubDate: 2016-10-09
      DOI: 10.3390/f7100227
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 228: Partitioning Tree Species Diversity and
           Developmental Changes in Habitat Associations in a Subtropical Evergreen
           Broadleaf Secondary Forest in Southern China

    • Authors: Wei Cui, Xiao-Xian Zheng
      First page: 228
      Abstract: The classical environmental control model assumes that species diversity is primarily determined by environmental conditions (e.g., microclimate and soil) on the local scale. This assumption has been challenged by the neutral theory that assumes that the maintenance of biodiversity mainly depends on the ecological drift and dispersal limitation. Understanding the mechanisms that maintain biodiversity depends on decomposing the variation of species diversity into the contributions from the various components that affect it. We investigated and partitioned the effects of the biotic component (productivity, forest spatial structure) and the environmental component (topography and soil fertility) on the distribution of tree species richness jointly (the combined effect of environment and biotic process) and separately (the effect of environment or biotic process alone) in 25 permanent plots of 600 m2 in a subtropical evergreen broadleaf secondary forest in southern China. The analysis was also completed for trees at different growth stages based on diameter breast height (young trees: 5 cm ≤ DBH < 10 cm, mature trees: 10 cm < DBH ≤ 20 cm, old trees: DBH > 20 cm) within each plot. Our results indicated that (1) tree species richness had significant negative relationship with productivity and a unimodal relationship with its spatially structured distribution; (2) biotic and environmental factors both have significant influence on species richness and jointly explain ~60% of the variation for the overall tree assemblage, and the variation explained by the two components jointly increased across growth stages (34%, 44%, and 75%, respectively); (3) additive variation partitioning revealed that the tree species richness was dominantly controlled by environmental factors (32%), while the biotic component also independently contributed a non-negligible effect (16%); and (4) the dominant fraction changed from the biotic component to the environmental component across growth stages. Results suggest that the tree species richness may be governed from neutral process to environmental control during tree life span in subtropical evergreen broadleaf secondary forests.
      PubDate: 2016-10-14
      DOI: 10.3390/f7100228
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 229: Operational Research Techniques Used for
           Addressing Biodiversity Objectives into Forest Management: An Overview

    • Authors: Marta Ezquerro, Marta Pardos, Luis Diaz-Balteiro
      First page: 229
      Abstract: The integration of biodiversity into forest management has traditionally been a challenge for many researchers and practitioners. In this paper, we have provided a survey of forest management papers that use different Operations Research (OR) methods in order to integrate biodiversity objectives into their planning models. One hundred and seventy-nine references appearing in the ISI Web of Science database in the last 30 years have been categorized and evaluated according to different attributes like model components, forest management elements, or biodiversity issues. The results show that many OR methods have been applied to deal with this challenging objective. Thus, up to 18 OR techniques, divided into four large groups, which have been employed in four or more articles, have been identified. However, it has been observed how the evolution of these papers in time apparently tended to increase only until 2008. Finally, two clear trends in this set of papers should be highlighted: the incorporation of spatial analysis tools into these operational research models and, second, the setting up of hybrid models, which combine different techniques to solve this type of problem.
      PubDate: 2016-10-12
      DOI: 10.3390/f7100229
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 230: Three-Year Study on Diurnal and Seasonal CO2
           Sequestration of a Young Fraxinus griffithii Plantation in Southern Taiwan

    • Authors: Chung-I Chen, Ya-Nan Wang, Hsueh-Wen Lih, Jui-Chu Yu
      First page: 230
      Abstract: This study examined monthly carbon sequestration of the Himalayan ash (Fraxinus griffithii C. B. Clarke), an important plantation species in Taiwan. From January 2010 to December 2012, data were collected from an F. griffithii plantation in southern Taiwan, which experiences a typical Southeast Asia monsoon climate. To estimate CO2 sequestration rate, we conducted diurnal measurements of photosynthetic rates and seasonal measurements of photosynthetic light response curves. We also calculated leaf area index to estimate the total leaf area of individual trees. The diurnal variation in photosynthetic rate, stomatal conductance, and transpiration exhibited seasonal and annual differences. The range of net CO2 assimilation rates was 1.34–8.68 µmol·m−2·s−1 in 2010, 1.02–6.60 µmol·m−2·s−1 in 2011, and 1.13–4.45 µmol·m−2·s−1 in 2012. A single F. griffithii tree sequestrated 12.21 kg·year−1 CO2 on average. Annual CO2 sequestration occurred primarily during the summer for all years, averaging 14.89 Mg·ha−1·year−1 for three years. Correlation analyses between various environmental variables and CO2 sequestration rates indicated that air temperature and soil water content were likely the main factors influencing carbon sequestration of F. griffithii at this study site.
      PubDate: 2016-10-14
      DOI: 10.3390/f7100230
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 231: Long-Term (13 Years) Decomposition Rates of
           Forest Floor Organic Matter on Paired Coniferous and Deciduous Watersheds
           with Contrasting Temperature Regimes

    • Authors: Robert Qualls
      First page: 231
      Abstract: Two sets of paired watersheds on north and South facing slopes were utilized to simulate the effects of temperature differences that are on the scale of those expected with near-term climatic warming on decomposition. Two watersheds were pine plantations (Pinus strobus L.) and two were mature deciduous forests established at similar elevation ranges and precipitation at the Coweeta Hydrologic Laboratory, but they differed in slope aspect (north vs. South facing), solar radiation, and litter temperature by about 2.0 °C. Nylon netting was placed on plots each year for 13 years and litterfall was measured. This time span in which decomposition rate was measured encompassed the time until less than 8% of the initial C remained. Decomposition rates of foliar litter were significantly faster on the slightly warmer watersheds, in both the coniferous and deciduous forests (Analysis of Variance). The turnover rate (year−1) was 0.359 (±0.006) for the South facing vs. 0.295 (±0.011) for the North facing coniferous watersheds, and 0.328 (±0.011) vs. 0.297 (±0.012) for the corresponding deciduous watersheds. Turnover rates of pine vs. deciduous broadleaf litter over 13 years were not significantly different because of the high proportion of relatively refractory Quercus spp. in the deciduous litterfall and because of a trend towards convergence of the rates after two years. After a greater decomposition rate in the first year or two, years 2–13 fit a negative exponential curve well (a timespan not well represented in literature) and there was only a small accumulation of humus older than 13 years. The fate of C in litterfall in the South facing deciduous forest was as follows: 14.3% was lost as leaching of dissolved organic C, 2.2% was lost as downward fine particulate matter flux from the bottom of the forest floor, 78.2% was mineralized (by mass balance), leaving only 5.4% of foliar litter after 13 years of decomposition. In these soils with a mor type O horizon, there was evidence that translocation of DOC and in-situ root production must be more important sources of mineral soil organic matter than downward migration of particulate humus.
      PubDate: 2016-10-12
      DOI: 10.3390/f7100231
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 232: Spatial Heterogeneity in Chinese Forest Area
           Change in the Early 21st Century

    • Authors: Jiayue Wang, Liangjie Xin, Minghong Tan, Yahui Wang
      First page: 232
      Abstract: A comprehensive set of 30-m resolution land coverage data of 2000 and 2010 was used for an analysis of the spatial heterogeneity of forest area change in early 21st century China. Four regression models were built to determine the current situation of the ‘forest transition’ in China. The results show that forest area in China has grown rapidly over this period such that total forest area has increased by 102,500 km2 and forest cover has increased by 1.06%. Our results demonstrate the presence of a ‘U-shaped’ relationship, the so-called ‘forest transition’, between forest area change and per capita gross domestic product (GDP). We estimate that the inflection point in the Chinese ‘forest transition’ will be at a per capita GDP of 50,522 yuan. In the future, regions with lower elevations, or slope, should be the focus of attention because of dramatic recent forest changes. In particular, forest areas in the regions of the Xiaoxing’anling-Changbaishan Mountains and in South China have markedly decreased, and these are areas of concern. In the meantime, the government needs to strengthen the management of large-scale interconversions between forest and grassland.
      PubDate: 2016-10-12
      DOI: 10.3390/f7100232
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 233: Comparative Study of Local and National Media
           Reporting: Conflict around the TV Oak in Stockholm, Sweden

    • Authors: Johan Östberg, Daniela Kleinschmit
      First page: 233
      Abstract: The TV oak (Television Oak) conflict concerned felling an old tree in a wealthy area of Stockholm. The case received great public attention in different media formats with different scopes (e.g., newspapers, television, internet). The TV Oak issue involved actors with different, partly conflicting perceptions. Assuming that the relevance of urban tree management issues in particular leads to increased interest among the local audience, this paper compared differences in reporting on the TV Oak case in local and national newspapers. The comparison comprised the actors “speaking” in the newspapers, the interest roles attributed to different actors and the frames used. The empirical materials used were articles concerning the TV Oak published between October 2011 and June 2012 in one local and two national Swedish newspapers. Quantitative analysis of statements in these articles showed that the geographical scope of the newspaper was not the major driving force framing the TV Oak conflict and that variety of framings, ranging from a humanised perception of the oak to a more analytical hazard perception, were used. Differences between the interest roles allocated to different actors (e.g., in terms of victim, causer, and helper in the oak conflict) showed that the framing of conflicts very much depended on single actors, in particular a high profile journalist in the national newspapers and private individuals writing letters to the editor in the local newspaper.
      PubDate: 2016-10-13
      DOI: 10.3390/f7100233
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 234: Early Stage Fine-Root Decomposition and Its
           Relationship with Root Order and Soil Depth in a Larix gmelinii Plantation

    • Authors: Tao Sun, Lili Dong, Lili Zhang, Zhijie Wu, Qingkui Wang, Yuanyuan Li, Hongguang Zhang, Zhengwen Wang
      First page: 234
      Abstract: Characterization of decomposition dynamics of fine roots is essential for understanding vegetation–soil feedbacks and predicting ecosystem responses to future climate scenarios, given their more rapid turnover rates. Using a branch-order classification, we separated the fine root systems of Larix gmelinii into two classes: first- and second-order roots combined into one (lower-order); third- and fourth-order roots combined into another (higher-order). In a field experiment, we conducted a litterbag study to investigate fine root decomposition and its relationship with root order class and soil depth over 17 months. Despite their lower C:N ratio and smaller diameter, lower-order roots decomposed more slowly compared with higher-order roots over this period. This pattern also seems to hold true at each different depths (10, 20 and 30 cm) in the soil profile. Our data suggest that the slow decomposition rate of lower-order roots may result from their poor carbon quality. Moreover, we found that the decomposition rates of both lower-order and higher-order roots decreased linearly from 10 cm to 30 cm, which implied that a substantially larger fraction of fine root mass would be stabilized as soil organic carbon in the deeper rather than the upper soil layers.
      PubDate: 2016-10-13
      DOI: 10.3390/f7100234
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 235: Climatic Sensitivity of a Mixed Forest
           Association of White Spruce and Trembling Aspen at Their Southern Range

    • Authors: Sophan Chhin, G. Wang
      First page: 235
      Abstract: Climatic sensitivity of white spruce (Picea glauca (Moench) Voss) was examined growing in association with trembling aspen (Populus tremuloides Michx.) at their southern limit of distribution in a transitional ecotone between the southern boreal forest and northern prairie region. The study was carried out in the Spruce Woods Provincial Park (SWPP) located in southwestern Manitoba, Canada. The dry regional climate restricted trembling aspen growth during the growing season via moisture deficiency and temperature induced drought stress. Warm, mild winters also negatively affected radial growth of trembling aspen. Growth of white spruce was moderated by conditions within the aspen stands as radial growth patterns showed low variability from year to year, a low common growth signal, and a stronger response to temperature than to precipitation. Nonetheless, the dry regional climate still restricted growth of white spruce during the growing season via temperature induced drought stress. The findings of the study for white spruce support the stress gradient hypothesis in which facilitative interactions between tree species are expected under harsher environmental conditions.
      PubDate: 2016-10-14
      DOI: 10.3390/f7100235
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 236: The Dynamic Trend of Soil Water Content in
           Artificial Forests on the Loess Plateau, China

    • Authors: Yu Wang, Qing-Ke Zhu, Wei-Jun Zhao, Huan Ma, Rui Wang, Ning Ai
      First page: 236
      Abstract: Extensive vegetation restoration projects have been widely implemented on the Loess Plateau, China, since 1998. In addition, increasing attention has been paid to the influence of revegetation on soil water. However, the response of the soil water content (SWC) to vegetation construction and management has not been adequately studied. In this study, three types of typical artificial vegetation on level bench land were selected, including Pinus tabulaeformis Carr., Prunus sibirica L., and Hippophae rhamnoides Linn., with the natural grassland used as a control group in Wuqi County. The 0–160 cm SWC was monitored biweekly from August 2010 to June 2013 using a portable time domain reflectometry system. The serial autocorrelation test, Mann–Kendall trend test, and prewhitening Mann–Kendall test were employed to systematically analyze the trends in soil water dynamics. The results show that the SWC of the three selected artificial forests/shrub had a significant accumulation process in the 0–160 cm profile during the monitoring period, whereas such an increasing tendency was not observed for natural grassland. Furthermore, the greatest responses were observed in the Pinus tabulaeformis Carr. plantation.
      PubDate: 2016-10-14
      DOI: 10.3390/f7100236
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 237: Beyond Fuel Treatment Effectiveness:
           Characterizing Interactions between Fire and Treatments in the US

    • Authors: Kevin Barnett, Sean Parks, Carol Miller, Helen Naughton
      First page: 237
      Abstract: In the United States, fuel reduction treatments are a standard land management tool to restore the structure and composition of forests that have been degraded by past management. Although treatments can have multiple purposes, their principal objective is to create landscape conditions where wildland fire can be safely managed to help achieve long-term land management goals. One critique is that fuel treatment benefits are unlikely to transpire due to the low probability that treated areas will be burned by a subsequent fire within a treatment’s lifespan, but little quantitative information exists to corroborate this argument. We summarized the frequency, extent, and geographic variation of fire and fuel treatment interactions on federal lands within the conterminous United States (CONUS). We also assessed how the encounters between fuel treatments and fires varied with treatment size, treatment age, and number of times treated. Overall, 6.8% of treatment units evaluated were encountered by a subsequent fire during the study period, though this rate varied among ecoregions across the CONUS. Larger treatment units were more likely to be encountered by a fire, and treatment units were most frequently burned within one year of the most recent treatment, the latter of which is likely because of ongoing maintenance of existing treatments. Our results highlight the need to identify and prioritize additional opportunities to reduce fuel loading and fire risk on the millions of hectares of federal lands in the CONUS that are in need of restoration.
      PubDate: 2016-10-14
      DOI: 10.3390/f7100237
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 238: Individual-Tree Competition Indices and
           Improved Compatibility with Stand-Level Estimates of Stem Density and
           Long-Term Production

    • Authors: John McTague, Aaron Weiskittel
      First page: 238
      Abstract: When explaining the dynamics of individual trees, the incorporation of size and distance of neighboring trees into a model can improve the prediction of growth and mortality. Several methods have been proposed to define the number of competing trees based on variable zone radii and the principles of angle count sampling. The task of measuring position-dependent competition indices appears to be ideally suited for permanent sample plots and long-term studies of growth and yield (production), where the marginal effort of remeasurement is concentrated on measuring size attributes of survivor trees and the occasional distance of a new sample tree. The proposed competition index is based on point sampling with a variable basal area factor (BAFV) that is partially derived from the Spurr (1962) competition index. Point sampling is a fast, easy, and inexpensive methodology for selecting the number of competing trees, and the new BAFV methodology proved to be very efficient for estimating growth. With the selection of an appropriate basal area factor, it is possible to reduce the number of subject trees and competition trees in the sample, and eliminate the need for edge correction methods. Although the index value assigned to the subject tree using the BAFV is biased, an appropriate correction is presented and discussed. The average competition index obtained from using the corrected value for the subject tree and the BAFV for the competing trees equals the stand level estimate of basal area.
      PubDate: 2016-10-15
      DOI: 10.3390/f7100238
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 239: Effects of Drought and Rewetting on Growth and
           Gas Exchange of Minor European Broadleaved Tree Species

    • Authors: Jörg Kunz, Annemarie Räder, Jürgen Bauhus
      First page: 239
      Abstract: Widespread and economically important European tree species such as Norway spruce, Scots pine, and European beech are projected to be negatively affected by the increasing intensity and frequency of dry and hot conditions in a future climate. Hence, there is an increasing need to investigate the suitability of presumably more drought tolerant species to ensure future ecological stability, biodiversity, and productivity of forests. Based on their distribution patterns and climatic envelopes, the rare, minor broadleaved tree species Sorbus torminalis ((L.) CRANTZ), S. domestica (L.), Acer campestre (L.), and A. platanoides (L.) are assumed to be drought tolerant, however, there is only limited experimental basis to support that notion. This study aimed at quantifying growth and gas exchange of seedlings of these species during drought conditions, and their capacity to recover following drought. For that purpose, they were compared to the common companion species Quercus petraea ((MATTUSCHKA) LIEBL.) and Fagus sylvatica (L.). Here, potted seedlings of these species were exposed to water limitation followed by rewetting cycles in a greenhouse experiment. Photosynthesis and transpiration rates, stomatal conductance as well as root and shoot growth rates indicated a high drought resistance of A. campestre and A. platanoides. Sorbus domestica showed a marked ability to recover after drought stress. Therefore, we conclude that these minor tree species have the potential to enrich forests on drought-prone sites. Results from this pot experiment need to be complemented by field studies, in which the drought response of the species is not influenced by restrictions to root development.
      PubDate: 2016-10-15
      DOI: 10.3390/f7100239
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 240: Radial Growth Response of Black Spruce Stands
           Ten Years after Experimental Shelterwoods and Seed-Tree Cuttings in Boreal

    • Authors: Miguel Montoro Girona, Hubert Morin, Jean-Martin Lussier, Denis Walsh
      First page: 240
      Abstract: Partial cutting is thought to be an alternative to achieve sustainable management in boreal forests. However, the effects of intermediate harvest intensity (45%–80%) on growth remain unknown in black spruce (Picea mariana (Mill.) B.S.P.) stands, one of the most widely distributed boreal species with great commercial interest. In this study, we analysed the effect of three experimental shelterwood and one seed-tree treatments on tree radial growth in even-aged black spruce stands, 10 years after intervention. Our results show that radial growth response 8–10 years after cutting was 41% to 62% higher than in untreated plots, with stand structure, treatment, tree position relative to skidding trails, growth before cutting and time having significant interactions. The stand structure conditioned tree growth after cutting, being doubled in younger and denser stands. Tree spatial position had a pronounced effect on radial growth; trees at the edge of the skidding trails showed twice the increase in growth compared to interior trees. Dominant trees before cutting located close to the skidding trails manifested the highest growth response after cutting. This research suggests that the studied treatments are effective to enhance radial wood production of black spruce especially in younger stands, and that the edge effect must be considered in silvicultural management planning.
      PubDate: 2016-10-15
      DOI: 10.3390/f7100240
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 241: How Biotic Differentiation of Human Impacted
           Nutrient Poor Deciduous Forests Can Affect the Preservation Status of
           Mountain Forest Vegetation

    • Authors: Tomasz Durak, Roma Durak
      First page: 241
      Abstract: A significant loss of biodiversity resulting from human activity has caused biotic homogenisation to become the dominant process shaping forest communities. In this paper, we present a rare case of biotic differentiation in European temperate deciduous forest herb layer vegetation. The process is occurring in nutrient poor oak-hornbeam forests in mountain areas (Polish Eastern Carpathians, Central Europe) where non-timber use was converted into conventional forest management practice. This change contributed to increases in the nitrogen content and pH reaction of the soil that, contrary to predominant beliefs on the negative impact of habitat eutrophication on diversity, did not result in a decrease in the latter. We discuss possible reasons for this phenomenon that indicate the important role of tree stand composition (an increasing admixture of beech worsening the trophic properties of the soil). The second issue considered involves the effect of the changes in herb species composition of oak-hornbeam forest on its distinctiveness from the beech forest predominating in the Polish Eastern Carpathians. Unfortunately, despite the increase in the species compositional dissimilarity of oak-hornbeam forest, a reduction in their distinctiveness in relation to the herb species composition of beech forest was found. Such a phenomenon is an effect of the major fragmentation of oak-hornbeam forests, a spread of beech forest-type species, and forest management that gives preference to beech trees. Consequently, it can be expected that changes occurring in oak-hornbeam forest vegetation will contribute to a decrease in the forest vegetation variability at the regional scale.
      PubDate: 2016-10-19
      DOI: 10.3390/f7100241
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 242: Tropical Forestry Handbook, Second Edition.
           Edited by Laslo Pancel and Michael Köhl, Springer-Verlag, 2016; 3633
           pages, 4 Volumes. Price: $2,500.00, ISBN 978-3-642-54600-6

    • Authors: Shu-Kun Lin
      First page: 242
      Abstract: n/a
      PubDate: 2016-10-20
      DOI: 10.3390/f7100242
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 243: Can Retention Harvest Maintain Natural
           Structural Complexity? A Comparison of Post-Harvest and Post-Fire Residual
           Patches in Boreal Forest

    • Authors: Louiza Moussaoui, Nicole Fenton, Alain Leduc, Yves Bergeron
      First page: 243
      Abstract: Variable retention harvest promotes biodiversity conservation in managed boreal forests by ensuring forest continuity and structural complexity. However, do post-harvest and post-fire patches maintain the same structural complexity? This study compares post-harvest and post-fire residual patches and proposes retention modalities that can maintain the same structural complexity as in natural forests, here considering both continuous forest stands and post-fire residual patches. In boreal black spruce forests, 41 post-fire residual patches, and 45 post-harvest retention patches of varying size and ages (exposure time to disturbed matrix) and 37 continuous forest stands were classified into six diameter structure types. Types 1 (inverted-J) and 2 (trunked-unimodal) characterized stands dominated by small trees. The abundance of small trees decreased and the abundance of large trees increased from Type 1 to Type 6. Type 6 had the most irregular structure with a wide range of diameters. This study indicates that: (1) old post-harvest residual retentions maintained the range of structural complexity found in natural stands; (2) Types 1 and 2 were generally associated with young post-fire patches and post-harvest retention clumps; (3) the structure of residual patches containing only small trees was usually younger (in terms of the age of the original forest from which residual patches were formed) than those with larger trees. To avoid the risk of simplifying the structure, retention patches should be intentionally oriented towards Types 3–6, dominated by intermediate and large trees.
      PubDate: 2016-10-21
      DOI: 10.3390/f7100243
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 244: Effect of 40 and 80 Years of Conifer Regrowth
           on Soil Microbial Activities and Community Structure in Subtropical Low
           Mountain Forests

    • Authors: Ed-Haun Chang, Tsai-Huei Chen, Guang-long Tian, Chun-Kai Hsu, Chih-Yu Chiu
      First page: 244
      Abstract: The effects of long-term reforestation on soil microbial communities and biomass are poorly understood. This study was conducted on two coniferous plantations: Cunninghamia konishii Hayata, planted 40 years ago (CONIF-40), and Calocedrus formosana (Florin) Florin, planted 80 years ago (CONIF-80). An adjacent natural broadleaf forest (BROAD-Nat) was used as a control. We determined microbial biomass C and N contents, enzyme activities, and community composition (via phospholipid fatty acid [PLFA] assessment). Both microbial biomass and PLFA content were higher in the summer than in the winter and differed among the forests in summer only. Total PLFA, total bacterial, gram-positive bacterial, gram-negative bacterial, and vesicular arbuscular mycorrhizal fungal contents followed the same pattern. Total fungal content and the ratios of fungi to bacteria and of gram-positive to gram-negative bacteria were highest in CONIF-40, with no difference between the other forests. Principal component analysis of PLFA contents revealed that CONIF-40 communities were distinct from those of CONIF-80 and BROAD-Nat. Our results suggest that vegetation replacement during reforestation exerts a prolonged impact on the soil microbial community. The understory broadleaf shrubs and trees established after coniferous plantation reforestation may balance out the effects of coniferous litter, contributing to bacterial recovery.
      PubDate: 2016-10-21
      DOI: 10.3390/f7100244
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 245: Deep Soil Conditions Make Mediterranean Cork
           Oak Stem Growth Vulnerable to Autumnal Rainfall Decline in Tunisia

    • Authors: Lobna Zribi, Florent Mouillot, Frederic Guibal, Salwa Rejeb, Mohamed Rejeb, Fatma Gharbi
      First page: 245
      Abstract: Tree rings provide fruitful information on climate features driving annual forest growth through statistical correlations between annual tree growth and climate features. Indices built upon tree growth limitation by carbon sequestration (source hypothesis) or drought-driven cambial phenology (sink hypothesis) can be used to better identify underlying processes. We used both analytical frameworks on Quercus suber, a sparsely studied species due to tree ring methodological issues, and growing on a favorable sub-humid Mediterranean climate and deep soil conditions in Tunisia (North Africa). Statistical analysis revealed the major role of autumnal rainfall before the growing season on annual tree growth over the 1918–2008 time series. Using a water budget model, we were able to explain the critical role of the deep soil water refill during the wet season in affecting both the drought onset controlling growth phenology and the summer drought intensity affecting carbon assimilation. Analysis of recent climate changes in the region additionally illustrated an increase in temperatures enhancing the evaporative demand and advancing growth start, and a decline in rainfalls in autumn, two key variables driving stem growth. We concluded on the benefits of using process-based indices in dendrochronological analysis and identified the main vulnerability of this Mediterranean forest to autumnal rainfall decline, a peculiar aspect of climate change under summer-dry climates.
      PubDate: 2016-10-21
      DOI: 10.3390/f7100245
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 246: Burning Potential of Fire Refuges in the
           Boreal Mixedwood Forest

    • Authors: Samira Ouarmim, Laure Paradis, Hugo Asselin, Yves Bergeron, Adam Ali, Christelle Hély
      First page: 246
      Abstract: In boreal ecosystems, wildfire severity (i.e., the extent of fire-related tree mortality) is affected by environmental conditions and fire intensity. A burned area usually includes tree patches that partially or entirely escaped fire. There are two types of post-fire residual patches: (1) patches that only escaped the last fire; and (2) patches with lower fire susceptibility, also called fire refuges, that escaped several consecutive fires, likely due to particular site characteristics. The main objective of this study was to test if particular environmental conditions and stand characteristics could explain the presence of fire refuges in the mixedwood boreal forest. The FlamMap3 fire behavior model running at the landscape scale was used on the present-day Lake Duparquet forest mosaic and on four other experimental scenarios. FlamMap3 was first calibrated using BehavePlus and realistic rates of fire spread obtained from the Canadian Fire Behavior Prediction system. The results, based on thousands of runs, exclude the effects of firebreaks, topography, fuel type, and microtopography to explain the presence of fire refuges, but rather highlight the important role of moisture conditions in the fuel beds. Moist conditions are likely attributed to former small depressions having been filled with organic matter rather than present-day variations in ground surface topography.
      PubDate: 2016-10-21
      DOI: 10.3390/f7100246
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 247: De Novo Assembly and Characterization of Bud,
           Leaf and Flowers Transcriptome from Juglans Regia L. for the
           Identification and Characterization of New EST-SSRs

    • Authors: Meng Dang, Tian Zhang, Yiheng Hu, Huijuan Zhou, Keith Woeste, Peng Zhao
      First page: 247
      Abstract: Persian walnut (Juglans regia L.), valued for both its nut and wood, is an ecologically important temperate tree species native to the mountainous regions of central Asia. Despite its importance, there are still few transcriptomic resources in public databases for J. regia, limiting gene discovery and breeding. Here, more than 49.9 million sequencing reads were generated using Illumina sequencing technology in the characterization of the transcriptome of four J. regia organs (bud, leaf, female flowers, and male flowers). De novo assembly yielded 117,229 unigenes with an N50 of 1955 bp. Based on sequence similarity searches against known proteins, a total of 20,413 (17.41%) genes were identified and annotated. A set of 27,584 unigenes with SSR (simple sequence repeats) motifs were identified as potential molecular markers, and a sample of 77 of these EST-SSRs (express sequence tags) were further evaluated to validate their amplification and assess their polymorphism. Next, we developed 39 polymorphic microsatellite markers to screen 88 Persian walnut individuals collected from 11 populations. These markers and transcriptomic resources will be useful for future studies of population genetic structure, evolutionary ecology, and breeding of Persian walnut and other Juglans species.
      PubDate: 2016-10-21
      DOI: 10.3390/f7100247
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 248: Host Defense Mechanisms against Bark Beetle
           Attack Differ between Ponderosa and Lodgepole Pines

    • Authors: Daniel West, Elisa Bernklau, Louis Bjostad, William Jacobi
      First page: 248
      Abstract: Conifer defenses against bark beetle attack include, but are not limited to, quantitative and qualitative defenses produced prior to attack. Our objective was to assess host defenses of lodgepole pine and ponderosa pine from ecotone stands. These stands provide a transition of host species for mountain pine beetle (Dendroctonus ponderosae; MPB). We asked two questions: (1) do the preformed quantitative host defenses (amount of resin) and (2) the preformed qualitative host defenses (monoterpene constituents) differ between lodgepole and ponderosa pines. We collected oleoresins at three locations in the Southern Rocky Mountains from 56 pairs of the pine species of similar size and growing conditions. The amount of preformed-ponderosa pine oleoresins exuded in 24 h (mg) was almost four times that of lodgepole pine. Total qualitative preformed monoterpenes did not differ between the two hosts, though we found differences in all but three monoterpenes. No differences were detected in α-pinene, γ-terpinene, and bornyl acetate. We found greater concentrations of limonene, β-phellandrene, and cymene in lodgepole pines, whereas β-pinene, 3-carene, myrcene, and terpinolene were greater in ponderosa pine. Although we found differences both in quantitative and qualitative preformed oleoresin defenses, the ecological relevance of these differences to bark beetle susceptibility have not been fully tested.
      PubDate: 2016-10-21
      DOI: 10.3390/f7100248
      Issue No: Vol. 7, No. 10 (2016)
  • Forests, Vol. 7, Pages 249: Water, Rather than Temperature, Dominantly
           Impacts How Soil Fauna Affect Dissolved Carbon and Nitrogen Release from
           Fresh Litter during Early Litter Decomposition

    • Authors: Shu Liao, Xiangyin Ni, Wanqin Yang, Han Li, Bin Wang, Changkun Fu, Zhenfeng Xu, Bo Tan, Fuzhong Wu
      First page: 249
      Abstract: Longstanding observations suggest that dissolved materials are lost from fresh litter through leaching, but the role of soil fauna in controlling this process has been poorly documented. In this study, a litterbag experiment employing litterbags with different mesh sizes (3 mm to permit soil fauna access and 0.04 mm to exclude fauna access) was conducted in three habitats (arid valley, ecotone and subalpine forest) with changes in climate and vegetation types to evaluate the effects of soil fauna on the concentrations of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) during the first year of decomposition. The results showed that the individual density and community abundance of soil fauna greatly varied among these habitats, but Prostigmata, Isotomidae and Oribatida were the dominant soil invertebrates. At the end of the experiment, the mass remaining of foliar litter ranged from 58% for shrub litter to 77% for birch litter, and the DOC and TDN concentrations decreased to 54%–85% and increased to 34%–269%, respectively, when soil fauna were not present. The effects of soil fauna on the concentrations of both DOC and TDN in foliar litter were greater in the subalpine forest (wetter but colder) during the winter and in the arid valley (warmer but drier) during the growing season, and this effect was positively correlated with water content. Moreover, the effects of fauna on DOC and TDN concentrations were greater for high-quality litter and were related to the C/N ratio. These results suggest that water, rather than temperature, dominates how fauna affect the release of dissolved substances from fresh litter.
      PubDate: 2016-10-24
      DOI: 10.3390/f7100249
      Issue No: Vol. 7, No. 10 (2016)
School of Mathematical and Computer Sciences
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