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  Subjects -> FORESTS AND FORESTRY (Total: 104 journals)
Acta Silvatica et Lignaria Hungarica     Open Access   (Followers: 1)
Advance in Forestry Research     Open Access   (Followers: 5)
Advances in Forestry Letters     Open Access   (Followers: 1)
Advances in Forestry Science     Open Access  
African Journal of Sustainable Development     Full-text available via subscription   (Followers: 7)
Agrociencia     Open Access   (Followers: 2)
Agroforestry Systems     Hybrid Journal   (Followers: 17)
Annals of Forest Science     Hybrid Journal   (Followers: 5)
Annals of Silvicultural Research     Open Access  
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: 7)
Arboriculture and Urban Forestry     Free   (Followers: 8)
Australian Forest Grower     Full-text available via subscription   (Followers: 2)
Australian Forestry     Full-text available via subscription   (Followers: 4)
Banko Janakari     Open Access  
Boletin de la Sociedad Argentina de Botanica     Open Access   (Followers: 1)
Bosque     Open Access   (Followers: 1)
Canadian Journal of Forest Research     Full-text available via subscription   (Followers: 24)
Canadian Journal of Plant Science     Full-text available via subscription   (Followers: 14)
Ciência Florestal     Open Access   (Followers: 2)
Ciencia forestal en México     Open Access   (Followers: 1)
Colombia Forestal     Open Access  
Current Forestry Reports     Hybrid Journal  
Dissertationes Forestales     Open Access  
European Journal of Forest Research     Hybrid Journal   (Followers: 6)
Expert Opinion on Environmental Biology     Hybrid Journal  
Floresta e Ambiente     Open Access   (Followers: 1)
Folia Forestalia Polonica     Open Access   (Followers: 1)
Forest Ecology and Management     Hybrid Journal   (Followers: 41)
Forest Pathology     Hybrid Journal   (Followers: 2)
Forest Phytophthoras     Open Access   (Followers: 2)
Forest Policy and Economics     Hybrid Journal   (Followers: 21)
Forest Research Papers     Open Access   (Followers: 4)
Forest Science     Full-text available via subscription   (Followers: 8)
Forest Science and Practice     Hybrid Journal   (Followers: 6)
Forest Science and Technology     Partially Free   (Followers: 2)
Forest Systems     Open Access   (Followers: 3)
Foresta Veracruzana     Open Access   (Followers: 2)
Forestry Chronicle     Full-text available via subscription   (Followers: 12)
Forestry Letters     Open Access  
Forestry Studies : Metsanduslikud Uurimused     Open Access   (Followers: 2)
Forestry: An International Journal of Forest Research     Hybrid Journal   (Followers: 13)
Forests     Open Access   (Followers: 4)
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  
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: 5)
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: 5)
Journal of Agriculture, Forestry and the Social Sciences     Full-text available via subscription   (Followers: 4)
Journal of Biodiversity Management & Forestry     Hybrid Journal   (Followers: 1)
Journal of Environmental Extension     Full-text available via subscription  
Journal of Forest and Livelihood     Full-text available via subscription  
Journal of Forest Economics     Hybrid Journal   (Followers: 6)
Journal of Forest Products and Industries     Open Access  
Journal of Forest Research     Hybrid Journal   (Followers: 4)
Journal of Forestry     Full-text available via subscription   (Followers: 11)
Journal of Forestry Research     Hybrid Journal   (Followers: 7)
Journal of Horticulture and Forestry     Open Access   (Followers: 1)
Journal of Natural Resources Policy Research     Hybrid Journal   (Followers: 16)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 3)
Journal of Sustainable Forestry     Hybrid Journal   (Followers: 8)
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: 3)
Jurnal Manajemen Hutan Tropika     Open Access   (Followers: 2)
Jurnal Penelitian Kehutanan Wallacea     Open Access  
La Calera     Open Access  
Landscapes     Hybrid Journal   (Followers: 21)
Lesnícky časopis     Open Access  
Maderas. Ciencia y tecnología     Open Access  
Mathematical and Computational Forestry & Natural-Resource Sciences     Free  
Natural Areas Journal     Full-text available via subscription   (Followers: 8)
New Forests     Hybrid Journal   (Followers: 2)
New Zealand Journal of Forestry Science     Open Access   (Followers: 1)
Open Journal of Forestry     Open Access   (Followers: 3)
Pesquisa Florestal Brasileira     Open Access   (Followers: 1)
Plant Science Bulletin     Free   (Followers: 8)
Quebracho. Revista de Ciencias Forestales     Open Access   (Followers: 1)
Research Journal of Forestry     Open Access   (Followers: 4)
Revista Árvore     Open Access   (Followers: 2)
Revista Chapingo. Serie Ciencias Forestales y del Ambiente     Open Access   (Followers: 2)
Revista de Agricultura Neotropical     Open Access  
Revista Verde de Agroecologia e Desenvolvimento Sustentável     Open Access   (Followers: 3)
Revue forestière française     Full-text available via subscription   (Followers: 3)
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: 3)
Southern African Forestry Journal     Full-text available via subscription   (Followers: 2)
Southern Forests : a Journal of Forest Science     Hybrid Journal   (Followers: 5)
Tanzania Journal of Forestry and Nature Conservation     Full-text available via subscription   (Followers: 2)
Trees     Hybrid Journal   (Followers: 5)

        1 2     

Journal Cover   Forests
  [SJR: 0.629]   [H-I: 8]   [4 followers]  Follow
  This is an Open Access Journal Open Access journal
   ISSN (Print) 1999-4907
   Published by MDPI Homepage  [140 journals]
  • Forests, Vol. 6, Pages 2897-2917: Evaluation of Image-Assisted Forest
           Monitoring: A Simulation

    • Pages: 2897 - 2917
      Abstract: Fiscal uncertainties can sometimes affect national continuous forest monitoring efforts. One solution of interest is to lengthen the time it takes to collect a “full set” of plot data from five to 10 years in order to reduce costs. Here, we investigate using ancillary information to partially offset this proposed solution’s negative effects. We focus our discussion on the corresponding number of years between measurements of each plot while we investigate how thoroughly the detrimental effects of the reduced sampling effort can be ameliorated with change estimates obtained from temporally-dense remotely-sensed images. We simulate measured plot data under four sampling error structures, and we simulate remotely-sensed change estimates under three reliability assumptions, integrated with assumptions about the additional unobserved growth resulting from the lengthened observation window. We investigate a number of estimation systems with respect to their ability to provide compatible annual estimates of the components of change during years spanned by at least half of the full set of plot observations. We show that auxiliary data with shorter observation intervals can contribute to a significant improvement in estimation.
      PubDate: 2015-08-25
      DOI: 10.3390/f6092897
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 2918-2940: Warm and Fertile Sub-Humid Conditions
           Enhance Litterfall to Sustain High Soil Respiration Fluxes in a
           Mediterranean Cork Oak Forest

    • Authors: Lobna Zribi, Florent Mouillot, Fatma Gharbi, Jean-Marc Ourcival, Belgacem Hanchi
      Pages: 2918 - 2940
      Abstract: Soil respiration is a major component of the global carbon budget and Mediterranean ecosystems have usually been studied in locations with shallow soils, mild temperatures, and a prolonged dry season. This study investigates seasonal soil respiration rates and underlying mechanisms under wetter, warmer, and more fertile conditions in a Mediterranean cork oak forest of Northern Tunisia (Africa), acknowledged as one of the most productive forests in the Mediterranean basin. We applied a soil respiration model based on soil temperature and relative water content and investigated how ecosystem functioning under these favorable conditions affected soil carbon storage through carbon inputs to the soil litter. Annual soil respiration rates varied between 1774 gC m−2 year−1 and 2227 gC m−2 year−1, which is on the highest range of observations under Mediterranean climate conditions. We attributed this high soil carbon flux as a response to favorable temperatures and soil water content, but this could be sustained only by a small carbon allocation to roots (root/shoot ratio = 0.31–0.41) leading to a large allocation to leaves with a multiannual leaf production, enhanced annual twig elongation (11.5–28.5 cm) with a reduced leaf life span (<1 year) maintaining a low LAI (1.68–1.88) and generating a high litterfall (386–636 gC m−2 year−1). Thus, the favorable climatic and edaphic conditions experienced by these Mediterranean cork oak forests drove high soil respiration fluxes which balanced the high carbon assimilation leading to a relatively small overall contribution (10.96–14.79 kgC m−2) to soil carbon storage.
      PubDate: 2015-08-26
      DOI: 10.3390/f6092918
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 2941-2958: Soil Nitrogen Transformations and
           Availability in Upland Pine and Bottomland Alder Forests

    • Authors: Tae Yoon, Nam Noh, Haegeun Chung, A-Ram Yang, Yowhan Son
      Pages: 2941 - 2958
      Abstract: Soil nitrogen (N) processes and inorganic N availability are closely coupled with ecosystem productivity and various ecological processes. Spatio-temporal variations and environmental effects on net N transformation rates and inorganic N concentrations in bulk soil and ion exchange resin were examined in an upland pine forest (UPF) and a bottomland alder forest (BAF), which were expected to have distinguishing N properties. The annual net N mineralization rate and nitrification rate (kg N·ha−1·year−1) were within the ranges of 66.05–84.01 and 56.26–77.61 in the UPF and −17.22–72.24 and 23.98–98.74 in the BAF, respectively. In the BAF, which were assumed as N-rich conditions, the net N mineralization rate was suppressed under NH4+ accumulated soils and was independent from soil temperature. On the other hand, in the UPF, which represent moderately fertile N conditions, net N transformation rates and N availability were dependent to the generally known regulation by soil temperature and soil water content. Stand density might indirectly affect the N transformations, N availability, and ecosystem productivity through different soil moisture conditions. The differing patterns of different inorganic N indices provide useful insight into the N availability in each forest and potential applicability of ion exchange resin assay.
      PubDate: 2015-08-27
      DOI: 10.3390/f6092941
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 2959-2981: Challenges in Mechanization Efforts of
           Small Diameter Eucalyptus Harvesting Operations with a Low Capacity
           Running Skyline Yarder in Southern China

    • Authors: Stephan Hoffmann, Dirk Jaeger, Siegmar Schoenherr, Bruce Talbot
      Pages: 2959 - 2981
      Abstract: This case study examines the performance of the Igland Hauler employed in small diameter Eucalyptus clear-cut operations in Guangxi, China. A yarding crew of eight persons was monitored by a snap back elemental time study for 19.23 SMH (scheduled machine hours), with 159 yarding cycles and a yarded log volume at landing of 49.4 m³ solid over bark. A gross-productivity of 2.50 m³/SMH and net-productivity of 5.06 m³/PMH0 (productive machine hours excluding delay times) was achieved, leading to a machine utilization rate of 49.5%. The costs of the yarder and associated overhead as well as the personnel costs of a large crew with eight people sum up to extraction costs of 50.24 USD/m³. The high costs make it difficult to compete economically with the locally common manual extraction system as long as abundant labor at a low hourly rate is available in the region. Further performance improvement through skill development, but also technical and organizational system modification in conjunction with rising wages and decreasing labor force in rural primary production will determine the justification of employing such yarding systems. However, new silvicultural regimes with extended rotations and supply requirements of the forest products industry in China demand new operational systems.
      PubDate: 2015-08-28
      DOI: 10.3390/f6092959
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 2982-3001: Mapping Temporal Dynamics in a Forest
           Stream Network—Implications for Riparian Forest Management

    • Pages: 2982 - 3001
      Abstract: This study focuses on avoiding negative effects on surface waters using new techniques for identifying wet areas near surface waters. This would aid planning and designing of forest buffer zones and off-road forestry traffic. The temporal variability in the geographical distribution of the stream network renders this type of planning difficult. A field study was performed in the 68 km2 Krycklan Catchment to illustrate the variability of a boreal stream network. The perennial stream length was 140 km while the stream length during high-flow conditions was 630 km. Comparing the field-measured stream network to the network presented on current maps showed that 58% of the perennial and 76% of the fully expanded network was missing on current maps. Similarly, cartographic depth-to-water maps showed that associated wet soils constituted 5% of the productive forest land during baseflow and 25% during high flow. Using a new technique, maps can be generated that indicate full stream networks, as well as seasonally active streams and associated wet soils, thus, forestry planning can be performed more efficiently and impacts on surface waters can be reduced.
      PubDate: 2015-08-28
      DOI: 10.3390/f6092982
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3002-3027: Determination of Fertility Rating (FR)
           in the 3-PG Model for Loblolly Pine Plantations in the Southeastern United
           States Based on Site Index

    • Authors: Santosh Subedi, Thomas Fox, Randolph Wynne
      Pages: 3002 - 3027
      Abstract: Soil fertility is an important component of forest ecosystems, yet evaluating soil fertility remains one of the least understood aspects of forest science. We hypothesized that the fertility rating (FR) used in the model 3-PG could be predicted from site index (SI) for loblolly pine in the southeastern US and then developed a method to predict FR from SI to test this hypothesis. Our results indicate that FR values derived from SI when used in 3-PG explain 89% of the variation in loblolly pine yield. The USDA SSURGO dataset contains SI values for loblolly pine for the major soil series in most of the counties in the southeastern US. The potential of using SI from SSURGO data to predict regional productivity of loblolly pine was assessed by comparing SI values from SSURGO with field inventory data in the study sites. When the 3-PG model was used with FR values derived using SI values from SSURGO database to predict loblolly pine productivity across the broader regions, the model provided realistic outputs of loblolly pine productivity. The results of this study show that FR values can be estimated from SI and used in 3-PG to predict loblolly pine productivity in the southeastern US.
      PubDate: 2015-08-28
      DOI: 10.3390/f6093002
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3028-3044: Economic Valuation of Mangroves for
           Comparison with Commercial Aquaculture in South Sulawesi, Indonesia

    • Authors: Abdul Malik, Rasmus Fensholt, Ole Mertz
      Pages: 3028 - 3044
      Abstract: Mangroves are recognized as a provider of a variety of products and essential ecosystem services that contribute significantly to the livelihood of local communities. However, over the past decades, mangroves in many tropical areas including the Takalar district, South Sulawesi have degraded and decreased mainly due to conversion to aquaculture. Currently, little is known about the economic benefits of commercialization of aquaculture as compared to those derived from mangroves in the form of products and services. Here, we estimate the Total Economic Value (TEV) of mangrove benefits in order to compare it with the benefit value of commercial aquaculture. Market prices, replacement costs, benefit transfer value and Cost-Benefit Analyses (CBA) have been used for value determination and comparison. The results show that the per year TEV of mangroves in the study area (Takalar district, South Sulawesi) was in the range of 4370 thousands USD (kUSD) to 10,597 kUSD or 4 kUSD to 8 kUSD per hectare (the highest value contribution derived from the indirect use value (94%)), whereas commercial aquaculture had a net benefit value of 228 kUSD or 3 kUSD per hectare. In addition, the comparison of Net Present Value (NPV) between the benefit value of mangroves and that of commercial aquaculture revealed that conversion of mangroves into commercial aquaculture was not economically beneficial when the analysis was expanded to cover the costs of environmental and forest rehabilitation.
      PubDate: 2015-08-31
      DOI: 10.3390/f6093028
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3045-3059: Economic Impact of Net Carbon Payments
           and Bioenergy Production in Fertilized and Non-Fertilized Loblolly Pine

    • Authors: Prativa Shrestha, George Stainback, Puneet Dwivedi
      Pages: 3045 - 3059
      Abstract: Sequestering carbon in forest stands and using woody bioenergy are two potential ways to utilize forests in mitigating emissions of greenhouse gases (GHGs). Such forestry related strategies are, however, greatly influenced by carbon and bioenergy markets. This study investigates the impact of both carbon and woody bioenergy markets on land expectation value (LEV) and rotation age of loblolly pine (Pinus taeda L.) forests in the southeastern United States for two scenarios—one with thinning and no fertilization and the other with thinning and fertilization. Economic analysis was conducted using a modified Hartman model. The amount of carbon dioxide (CO2) emitted during various activities such as management of stands, harvesting, and product decay was included in the model. Sensitivity analysis was conducted with a range of carbon offset, wood for bioenergy, and forest product prices. The results showed that LEV increased in both management scenarios as the price of carbon and wood for bioenergy increased. However, the results indicated that the management scenario without fertilizer was optimal at low carbon prices and the management scenario with fertilizer was optimal at higher carbon prices for medium and low forest product prices. Carbon payments had a greater impact on LEV than prices for wood utilized for bioenergy. Also, increase in the carbon price increased the optimal rotation age, whereas, wood prices for bioenergy had little impact. The management scenario without fertilizer was found to have longer optimal rotation ages.
      PubDate: 2015-08-31
      DOI: 10.3390/f6093045
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3060-3074: Impacts of Mastication: Soil Seed Bank
           Responses to a Forest Thinning Treatment in Three Colorado (USA) Conifer
           Forest Types

    • Authors: Akasha Faist, Heather Stone, Erin Tripp
      Pages: 3060 - 3074
      Abstract: Mastication is a forest fuel thinning treatment that involves chipping or shredding small trees and shrubs and depositing the material across the forest floor. By decreasing forest density mastication has been shown to lessen crown fire hazard, yet other impacts have only recently started to be studied. Our study evaluates how mastication treatments alter the density and composition of soil seed banks in three Colorado conifer forest types. The three forest types were (1) lodgepole pine, (2) ponderosa pine and (3) pinyon pine-juniper. Results showed that masticated sites contained higher seed bank densities than untreated sites: a pattern primarily driven by treatment effects in ponderosa pine forests. The seed bank was dominated by forbs regardless of forest type or treatment. This pattern of forb dominance was not observed in the aboveground vegetation cover as it demonstrated more even proportions of the functional groups. Graminoids showed a higher seed density in treated sites than untreated and, similarly, the identified non-native species only occurred in the treated ponderosa pine sites suggesting a potential belowground invasion for this forest type. These results suggest that presence of masticated material might not be creating a physical barrier hindering the transfer of seeds as predicted.
      PubDate: 2015-08-31
      DOI: 10.3390/f6093060
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3075-3086: A High-Resolution Map of Emerald Ash
           Borer Invasion Risk for Southern Central Europe

    • Authors: Viktoria Valenta, Dietmar Moser, Michael Kuttner, Johannes Peterseil, Franz Essl
      Pages: 3075 - 3086
      Abstract: Ash species (Fraxinus spp.) in Europe are threatened by the Emerald Ash Borer (Agrilus planipennis, EAB), an invasive wood boring beetle native to East Asia and currently spreading from European Russia westwards. Based on a high-resolution habitat distribution map (grid cell size: 25 × 25 m) and data on distribution and abundance of Common Ash (Fraxinus excelsior), the most widespread and highly susceptive host species of EAB in Europe, we assess the spatial distribution of EAB invasion risks for southern Central Europe (Austria, Switzerland, Liechtenstein, southern Germany, South Tyrol). We found highest F. excelsior abundance and thus invasion risks in extensive lowland floodplain forests, medium risks in zonal lowland forests and low risks in upper montane and subalpine forests. Based on average velocities of spread in Russia (13–31 km/year) and North America (2.5–80 km/year) from flight and human-assisted transport, EAB is likely to cover the distance (1500 km) between its current range edge in western Russia and the eastern border of the study region within few decades. However, secondary spread by infested wood products make earlier introductions likely. The high susceptibility and mortality of F. excelsior leave no doubt that this beetle will become a major forest pest once it reaches Central Europe. Therefore, developing and testing management approaches with the aim to halt or at least slow down the invasion of EAB in Europe have to be pursued with great urgency.
      PubDate: 2015-08-31
      DOI: 10.3390/f6093075
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3087-3108: Considering the Practical Rationality of
           Experimental Operation in Developing Countries: Reality and Challenges
           under a Rigid Community Forestry System in Cambodia

    • Authors: Takayuki Kurashima, Toshiya Matsuura, Asako Miyamoto, Makoto Sano, Sophal Chann
      Pages: 3087 - 3108
      Abstract: Influential stakeholders have highlighted many constraints inherent in conventional scientific forest management plans for community forestry (CF) and presented simpler alternatives. Nevertheless, some developing countries continue to use rigid, complex and high-cost plans and regulations. This article considers two issues: (1) why heavily-regulated or rigid CF systems were originally introduced and why they continue to be used in developing countries despite critiques and counterproposals; and (2) under what circumstances will such CF systems face an impasse, and what can be done to resolve the situation. Using Cambodia as a case study, we examine the development of a rigid CF system, review negative factors influencing the upland forested area, clarify the unfavorable situations arising from these factors and discuss likely problems associated with the CF management system. International organizations played a key role in the introduction and maintenance of rigid, complex and high-cost CF systems in Cambodia. Conflicts and crises arise when the administration prosecutes local farmers for illegal cultivation or deprives communities of CF management rights because of the expansion of commercial crop cultivation and the lack of adequate community management in response to unprecedented changes. A likely practical solution to the probable impasse is the development and funding of a functional network of CF management committees, rather than the adoption of an entirely new, alternative system.
      PubDate: 2015-09-07
      DOI: 10.3390/f6093087
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3109-3122: Effect of Hydropriming and Biopriming on
           Seed Germination and Growth of Two Mexican Fir Tree Species in Danger of

    • Pages: 3109 - 3122
      Abstract: Abies spp. in general have been shown to need a period of cold stratification to break dormancy and germinate, but this can be very time consuming. In this study, hydropriming by itself and in combination with biopriming was carried out on Abies hickelii and Abies religiosa seeds. For biopriming, three species of plant growth promoting rhizobacteria ( Pseudomonas fluorescens, P. putida and Bacillus subtilis) were tested. The purpose was to determine if germination and growth could be improved for these two endangered species. Our results demonstrated that treating A. hickelii and A. religiosa with both hydropriming and biopriming with certain strains of Plant Growth-Promoting Rhizobacteria (PGPR) could improve germination rates up to 91% for A. hickelii and up to 68% for A. religiosa. Importantly, these treatments showed no significant negative impact on the growth of A. religiosa and actually improved growth in A. hickelii. The application of both hydropriming and biopriming offer possibly an alternative methodology to improve germination, survival and preservation of these fir tree species of Mexico that are at risk of extinction.
      PubDate: 2015-09-07
      DOI: 10.3390/f6093109
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3123-3135: Previous Land Use and Invasive Species
           Impacts on Long-term Afforestation Success

    • Authors: Joshua Nickelson, Eric Holzmueller, John Groninger, Damon Lesmeister
      Pages: 3123 - 3135
      Abstract: The conversion of agricultural lands to forests has increased worldwide over the past few decades for multiple reasons including increasing forest connectivity and wildlife habitat. However, previous land cover and competing vegetation often impede afforestation. We established 219 plots in 29 Quercus plantations on four previous land cover types (LCT): Clover, Soybeans, Woody Brush, and Herbaceous Weeds. Plantations were located in Illinois, USA and were sampled 15–18 years after planting. Sampling data for all trees (planted and volunteer) included species, diameter, and vine presence on the main bole of the tree. Free-to-grow status was recorded for all Quercus species and estimated cover of two invasive species, Elaeagnus umbellata and Lonicera japonica, was documented on each plot. There was a strong relationship between total tree density and invasive species cover across all sites. Stocking success was lower and E. umbellata cover was higher on Woody Brush sites compared to Clover and Soybean cover types. Additionally, significantly more free-to-grow Quercus saplings occurred in Clover and Soybean cover types compared to the Woody Brush sites. The results indicate that previous land cover plays a critical role in forest afforestation. Furthermore, while historically, volunteer tree species were thought to be detrimental to the development of planted species these results suggest that with the increasing prevalence of invasive species worldwide the role of volunteer species in afforestation should be reconsidered and silvicultural protocols adjusted accordingly.
      PubDate: 2015-09-07
      DOI: 10.3390/f6093123
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3136-3164: Changing Perceptions of Forest Value and
           Attitudes toward Management of a Recently Established Nature Reserve: A
           Case Study in Southwest China

    • Authors: Hua Yang, Rhett Harrison, Zhuang-Fang Yi, Eben Goodale, Ming-Xu Zhao, Jian-Chu Xu
      Pages: 3136 - 3164
      Abstract: Identifying the main sources of conflict and understanding the relationships between protected areas and local communities are critical to conflict resolution related to protected area management. We surveyed and assessed the perceptions of local people related to forest values of the Bulong Nature Reserve (BNR), Yunnan, China, and their attitudes toward forest management of the recently-established nature reserve. Factors influencing the differences in perceptions and attitudes were investigated. Our results indicated local residents preferred the economic value of forests, and they perceived more forest values after reserve establishment than before, especially for ecological services. Interviewees believed the value of the forests have increased, and predicted that the forest will have increased importance to their livelihoods and health in the future. Nonetheless, the majority of interviewees were dissatisfied with current reserve management. Variation in these perceptions and attitudes were related to several social variables: age, gender, education, and distance from the reserve. Embedding the findings of the present study, specifically the perceptions and attitudes of local people, into management guidelines for mitigation of potential conflicts is proposed and should help managers to achieve biodiversity-related goals. This study offers new insights related to the identification of the underlying sources of conflict in forest management and provides a better understanding of the relationship between local people and protected areas. The study also contributes to the literature on forest values of indigenous populations by examining those of remote, rural populations in China.
      PubDate: 2015-09-09
      DOI: 10.3390/f6093136
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3165-3176: Effect of Chitosan on Disease Control
           and Growth of Scots Pine (Pinus sylvestris L.) in a Forest Nursery

    • Pages: 3165 - 3176
      Abstract: Chitosan has become a promising biological agent for disease control and plant growth promotion. The objective of this study was to assess the effects of chitosan, applied as an active ingredient of Beta-chikol (Poli-Farm, Łowicz, Poland), to control damping-off and Lophodermium needle cast on Scots pine seedlings growing in field conditions. Beta-chikol was used for seed treatment and as a foliar spray at recommended rates and concentrations. For each experimental variant (chitosan, fungicides, unprotected), inventories of seedlings were performed, after germination and again after six weeks. In the aboveground parts of seedlings, the concentration of endogenous salicylic acid was determined by HPLC. At the end of the growing season, seedling growth parameters were determined. Beta-chikol used as foliar spray limited infection by the damping-off fungi but was ineffective when used as a seed treatment. Lophodermium needle cast was not observed during the study period. After the application of Beta-chikol, the concentration of salicylic acid did not increase. The application of Beta-chikol enhanced all growth parameters under investigation. Our results indicate the possibility of using chitosan in the form of Beta-chikol to stimulate plant growth and protect pine seedlings against parasitic damping-off in forest nurseries.
      PubDate: 2015-09-11
      DOI: 10.3390/f6093165
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3177-3196: Variability of Stand Structures and
           Development in Old-Growth Forests in the Pacific Northwest, USA

    • Authors: Pil Park, Chadwick Oliver
      Pages: 3177 - 3196
      Abstract: The forest stand structure class “old-growth” has previously been qualitatively described as having several distinct “sub-structures.” Species composition, diameter distribution, and other structural features commonly associated with old-growth in the Pacific Northwest are quite variable. We determined which quantitative stand structure variables are commonly found together using the Spearman correlation and non-metric multidimensional analysis. Some features were more commonly found together than others, indicating different old-growth stand types, or sub-structures. Cluster analysis classified the old-growth forests into four groups: Douglas-fir dominance, shade tolerant species dominance, and intermediate groups. The intermediate groups were split by the density of large logs and large shade tolerant trees. The old-growth sub-structures appear to change from one to another as the old forest develops.
      PubDate: 2015-09-11
      DOI: 10.3390/f6093177
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3197-3211: Assessing Climate Change Impacts on
           Wildfire Risk in the United States

    • Authors: Hyunjin An, Jianbang Gan, Sung Cho
      Pages: 3197 - 3211
      Abstract: This study examines the statistical association of wildfire risk with climatic conditions and non-climate variables in 48 continental US states. Because the response variable “wildfire risk” is a fractional variable bounded between zero and one, we use a non-linear panel data model to recognize the bounded nature of the response variable. We estimate the non-linear panel data model (fractional probit) using the Generalized Estimating Equation (GEE) approach to ensure that the parameter estimation is efficient. The statistical model, coupled with the future climates projected by Global Climate Models (GCMs), is then employed to assess the impact of global climate change on wildfire risk. Our regression results show that wildfire risk is positively related to spring, summer, and winter temperatures and human population density whereas it is negatively associated with precipitation. The simulation results based on GCMs and the regression model indicate that climate change will intensify wildfire risk throughout the entire US, especially in the South Central region, posing an increasing wildfire threat and thus calling for more effective wildfire management strategies.
      PubDate: 2015-09-15
      DOI: 10.3390/f6093197
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3212-3217: Decision Support for the Provision of
           Ecosystem Services under Climate Change: An Editorial

    • Pages: 3212 - 3217
      Abstract: The Special Issue “Providing Ecosystem Services under Climate Change: Community of Practice of Forest Decision Support Systems” is based on the presentations given at the 24th World Congress of the International Union of Forest Research Organizations and provides an overview on Forest Management Decision Support Systems currently designed and applied for the sustained provision of ecosystem services within the context of climate change. The contributions provide an overview on models, methods, techniques used in decision support and the proposed frameworks to support decision making. With populations and economies growing worldwide, the demands on forest resources increase, and sustaining the supply of ecosystem services becomes crucial. Through growing public participation in decisions regarding the management of natural resources, new demands have emerged for tools that support our understanding of environmental issues, and for the development and evaluation of alternative management options; there is a desire to project the consequences of different courses of action. Decision Support Systems (DSS) have been proven to solve such ill-structured decision problems by integrating database management systems with analytical and operational research models, thus providing various reporting capabilities. Several case studies focus on decision problems, the development and evaluation of alternative management options, and on projecting the consequences of different courses of action in the provision of ecosystem services. Conclusions on the state-of-the-art in decision support and the needed advances in research are drawn.
      PubDate: 2015-09-16
      DOI: 10.3390/f6093212
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3218-3236: Accuracy of Kinematic Positioning Using
           Global Satellite Navigation Systems under Forest Canopies

    • Pages: 3218 - 3236
      Abstract: A harvester enables detailed roundwood data to be collected during harvesting operations by means of the measurement apparatus integrated into its felling head. These data can be used to improve the efficiency of wood procurement and also replace some of the field measurements, and thus provide both less costly and more detailed ground truth for remote sensing based forest inventories. However, the positional accuracy of harvester-collected tree data is not sufficient currently to match the accuracy per individual trees achieved with remote sensing data. The aim in the present study was to test the accuracy of various instruments utilizing global satellite navigation systems (GNSS) in motion under forest canopies of varying densities to enable us to get an understanding of the current state-of-the-art in GNSS-based positioning under forest canopies. Tests were conducted using several different combinations of GNSS and inertial measurement unit (IMU) mounted on an all-terrain vehicle (ATV) “simulating” a moving harvester. The positions of 224 trees along the driving route were measured using a total-station and real-time kinematic GPS. These trees were used as reference items. The position of the ATV was obtained using GNSS and IMU with an accuracy of 0.7 m (root mean squared error (RMSE) for 2D positions). For the single-frequency GNSS receivers, the RMSE of real-time 2D GNSS positions was 4.2–9.3 m. Based on these results, it seems that the accuracy of novel single-frequency GNSS devices is not so dependent on forest conditions, whereas the performance of the tested geodetic dual-frequency receiver is very sensitive to the visibility of the satellites. When post-processing can be applied, especially when combined with IMU data, the improvement in the accuracy of the dual-frequency receiver was significant.
      PubDate: 2015-09-16
      DOI: 10.3390/f6093218
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3237-3255: Complexity of Forest Management:
           Exploring Perceptions of Dutch Forest Managers

    • Authors: Jilske de Bruin, Marjanke Hoogstra-Klein, Godefridus Mohren, Bas Arts
      Pages: 3237 - 3255
      Abstract: Challenges of contemporary forest management are frequently referred to as complex. This article empirically studies complexity in forest management decision-making. In contrast to what is often assumed in the literature, this article starts by assuming that complexity does not just consist of an external descriptive element, but also depends on how decision-makers perceive the system at hand. This “perceived complexity” determines decision-making. We used a straightforward interpretation of perceived complexity using two criteria: the number of factors considered and the uncertainty perceived about these factors. The results show that Dutch forest managers generally consider forest management decision-making to be complicated (many factors to consider) rather than complex (many uncertain factors to consider). Differences in sources of complexity confirm the individual character of perceived complexity. The factors perceived to be most relevant for decision-making (the forest itself, the organization’s objective, the cost of management, public opinion, national policies and laws, and new scientific insights and ideas) are generally seen as rather certain, although “complexity reduction” may play a role that can adversely affect the quality of decision-making. Additional use of more open-ended, forward-looking methods, such as qualitative foresight tools, might enable addressing uncertainty and complexity, and thereby enhance decision-making in forest management to prepare for increasing complexity in the future.
      PubDate: 2015-09-17
      DOI: 10.3390/f6093237
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3256-3277: Tree- and Stand-Level Thinning Effects
           on Growth of European Beech (Fagus sylvatica L.) on a Northeast- and a
           Southwest-Facing Slope in Southwest Germany

    • Authors: Daniela Diaconu, Hans-Peter Kahle, Heinrich Spiecker
      Pages: 3256 - 3277
      Abstract: Anticipated changes in climate and research findings on the drought sensitivity of beech have triggered controversial discussions about the future of European beech. We investigated the growth response of beech on the tree- and stand-level in mature stands to three different thinning intensities (no thinning, strong thinning, very strong thinning) on a northeast- and southwest-facing slope in Southwest Germany. Linear mixed-effects models were formulated to describe effects on growth parameters on the tree- and stand-level (diameter, height, basal area, volume). At the stand-level, the stand basal area increment and stand volume increment were lower on the thinned plots. At the tree-level, the basal area increment significantly increased with increasing thinning intensity. The growth of individual trees was also influenced by initial tree size, the size-related rank of the tree within a stand, and by the aspect of the site. Our data indicate that growth of European beech is impaired on the southwest-facing slope with a warmer and drier climate and that a very strong thinning regime applied at advanced age can accelerate growth of European beech trees even on the warmer and drier site. Our findings, therefore, imply that in a warmer climate intensive thinning may also represent an important adaptive forest management measure in European beech stands.
      PubDate: 2015-09-21
      DOI: 10.3390/f6093256
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3278-3303: Exploring Local Perspectives for
           Conservation Planning: A Case Study from a Remote Forest Community in
           Indonesian Papua

    • Pages: 3278 - 3303
      Abstract: Reconciling conservation and livelihoods is a concern wherever forests are important in local people’s lives. We plead for engaging these people in survey activities to clarify what is important to them, as a first step in conservation planning. This will help to address their priorities and gain their guidance and support for interventions. This paper presents the results of such a survey with the community of Kwerba in Mamberamo, a remote and little known part of Indonesian Papua. Views and priorities were explored through interviews, scoring exercises, community mapping and a field survey. Whereas small gardens provided most staple food, culture and livelihoods were linked to the forest. People scored primary forest highest for nearly all use categories. Primary forest was particularly highly valued as a source of construction materials, ornaments and rituals, and as a hunting place. We developed a list of the overall most important plants and animals. Many natural resources were used, but few were commercially exploited. The community had rules to control access to certain areas and resources. Taboos to restrict access to sacred places were also maintained. Our evaluation identified opportunities to achieve conservation outcomes jointly with the Kwerba people. In follow-up activities, the community presented local government with a land-use plan for their territory. The government recognized the value of our approach and requested training to implement it more widely in the region.
      PubDate: 2015-09-22
      DOI: 10.3390/f6093278
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3304-3325: Carbon Dioxide and Methane Formation in
           Norway Spruce Stems Infected by White-Rot Fungi

    • Pages: 3304 - 3325
      Abstract: Globally, billions of tons of carbon sequestered in trees are annually recycled back to the atmosphere through wood decomposition by microbes. In Norway, every fifth Norway spruce shows at final harvest infection by pathogenic white-rot fungi in the genera Heterobasidion and Armillaria. As these fungi can mineralize all components of wood, we predicted that they have a significant carbon footprint. Gas samples taken from infected stems were analyzed for CO2 and CH4 concentrations, and wood samples from different parts of the decay columns were incubated under hypoxic (4% O2) and anoxic laboratory conditions. In spring and summer the stem concentrations of CO2 were generally two times higher in trees with heartwood decay than in healthy trees. For most of the healthy trees and trees with heartwood decay, mean stem concentrations of CH4 were comparable to ambient air, and only some Armillaria infected trees showed moderately elevated CH4. Consistently, low CH4 production potentials were recorded in the laboratory experiment. Up-scaling of CO2 efflux due to wood decay in living trees suggests that the balance between carbon sequestration and emission may be substantially influenced in stands with high frequency of advanced root and stem heartwood decay.
      PubDate: 2015-09-22
      DOI: 10.3390/f6093304
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3326-3352: Building on Two Decades of Ecosystem
           Management and Biodiversity Conservation under the Northwest Forest Plan,

    • Authors: Dominick DellaSala, Rowan Baker, Doug Heiken, Chris Frissell, James Karr, S. Nelson, Barry Noon, David Olson, James Strittholt
      Pages: 3326 - 3352
      Abstract: The 1994 Northwest Forest Plan (NWFP) shifted federal lands management from a focus on timber production to ecosystem management and biodiversity conservation. The plan established a network of conservation reserves and an ecosystem management strategy on ~10 million hectares from northern California to Washington State, USA, within the range of the federally threatened northern spotted owl (Strix occidentalis caurina). Several subsequent assessments—and 20 years of data from monitoring programs established under the plan—have demonstrated the effectiveness of this reserve network and ecosystem management approach in making progress toward attaining many of the plan’s conservation and ecosystem management goals. This paper (1) showcases the fundamental conservation biology and ecosystem management principles underpinning the NWFP as a case study for managers interested in large-landscape conservation; and (2) recommends improvements to the plan’s strategy in response to unprecedented climate change and land-use threats. Twenty years into plan implementation, however, the U.S. Forest Service and Bureau of Land Management, under pressure for increased timber harvest, are retreating from conservation measures. We believe that federal agencies should instead build on the NWFP to ensure continuing success in the Pacific Northwest. We urge federal land managers to (1) protect all remaining late-successional/old-growth forests; (2) identify climate refugia for at-risk species; (3) maintain or increase stream buffers and landscape connectivity; (4) decommission and repair failing roads to improve water quality; (5) reduce fire risk in fire-prone tree plantations; and (6) prevent logging after fires in areas of high conservation value. In many respects, the NWFP is instructive for managers considering similar large-scale conservation efforts.
      PubDate: 2015-09-22
      DOI: 10.3390/f6093326
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 3353-3368: Impact of Seed Transmission on the
           Infection and Development of Pitch Canker Disease in Pinus radiata

    • Authors: Margarita Evira-Recuenco, Eugenia Iturritxa, Rosa Raposo
      Pages: 3353 - 3368
      Abstract: The aim of this study was to determine the impact of seed inoculum on subsequent disease development in nurseries, specifically studying incidence of seed infection, transmission rate of seed to seedlings, and rate of disease development from the primary inoculum source. Transmission rate of Fusarium circinatum (F. circinatum) from symptomatic trees of Pinus radiata (P. radiata) to seed was 0.73%, being the fungus mainly on the coat. Seed infection incidence was positively correlated with tree disease severity. Seeds also become contaminated with F. circinatum during storage, where high relative humidity had a great effect regardless of temperature. Transmission rates from seeds to symptomatic seedlings measured at 48 days after seed inoculation with 104 and 106 was 28% and 80%, respectively. Seedlings showed symptoms of wilting and dieback, and eventually died within the total duration of this study (475 days). By this time, there were two remaining symptomless seedlings (1% of the total). F. circinatum was recovered from each of them, demonstrating its persistence in seedlings. Fungus populations in roots were estimated between 105 and 107 cfu/g in symptomatic plants for both inoculum doses and up to 104 cfu/g in asymptomatic plants. Disease infection rate was similar in post-emergence damping-off (up two months growing) and for established seedlings (up to eight months) after seeds were inoculated with 104 spores/mL.
      PubDate: 2015-09-23
      DOI: 10.3390/f6093353
      Issue No: Vol. 6, No. 9 (2015)
  • Forests, Vol. 6, Pages 2505-2529: Comparative Drought Responses of Quercus
           ilex L. and Pinus sylvestris L. in a Montane Forest Undergoing a
           Vegetation Shift

    • Pages: 2505 - 2529
      Abstract: Different functional and structural strategies to cope with water shortage exist both within and across plant communities. The current trend towards increasing drought in many regions could drive some species to their physiological limits of drought tolerance, potentially leading to mortality episodes and vegetation shifts. In this paper, we study the drought responses of Quercus ilex and Pinus sylvestris in a montane Mediterranean forest where the former species is replacing the latter in association with recent episodes of drought-induced mortality. Our aim was to compare the physiological responses to variations in soil water content (SWC) and vapor pressure deficit (VPD) of the two species when living together in a mixed stand or separately in pure stands, where the canopies of both species are completely exposed to high radiation and VPD. P. sylvestris showed typical isohydric behavior, with greater losses of stomatal conductance with declining SWC and greater reductions of stored non-structural carbohydrates during drought, consistent with carbon starvation being an important factor in the mortality of this species. On the other hand, Q. ilex trees showed a more anisohydric behavior, experiencing more negative water potentials and higher levels of xylem embolism under extreme drought, presumably putting them at higher risk of hydraulic failure. In addition, our results show relatively small changes in the physiological responses of Q. ilex in mixed vs. pure stands, suggesting that the current replacement of P. sylvestris by Q. ilex will continue.
      PubDate: 2015-07-27
      DOI: 10.3390/f6082505
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2530-2544: Modeling Potential Impacts of Planting
           Palms or Tree in Small Holder Fruit Plantations on Ecohydrological
           Processes in the Central Amazon

    • Authors: Norbert Kunert, Luiza Aparecido, Priscila Barros, Niro Higuchi
      Pages: 2530 - 2544
      Abstract: Native fruiting plants are widely cultivated in the Amazon, but little information on their water use characteristics can be found in the literature. To explore the potential impacts of plantations on local to regional water balance, we studied plant water use characteristics of two native fruit plants commonly occurring in the Amazon region. The study was conducted in a mixed fruit plantation containing a dicot tree species (Cupuaçu, Theobroma grandiflorum) and a monocot palm species (Açai, Euterpe oleracea) close to the city of Manaus, in the Central Amazon. Scaling from sap flux measurements, palms had a 3.5-fold higher water consumption compared to trees with a similar diameter. Despite the high transpiration rates of the palms, our plantation had only one third of the potential water recycling capacity of natural forests in the area. Converting natural forest into such plantations will thus result in significantly higher runoff rates.
      PubDate: 2015-07-27
      DOI: 10.3390/f6082530
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2545-2559: An Improved Weise’s Rule for
           Efficient Estimation of Stand Quadratic Mean Diameter

    • Pages: 2545 - 2559
      Abstract: The main objective of this study was to explore the accuracy of Weise’s rule of thumb applied to an estimation of the quadratic mean diameter of a forest stand. Virtual stands of European beech (Fagus sylvatica L.) across a range of structure types were stochastically generated and random sampling was simulated. We compared the bias and accuracy of stand quadratic mean diameter estimates, employing different ranks of measured stems from a set of the 10 trees nearest to the sampling point. We proposed several modifications of the original Weise’s rule based on the measurement and averaging of two different ranks centered to a target rank. In accordance with the original formulation of the empirical rule, we recommend the application of the measurement of the 6th stem in rank corresponding to the 55% sample percentile of diameter distribution, irrespective of mean diameter size and degree of diameter dispersion. The study also revealed that the application of appropriate two-measurement modifications of Weise’s method, the 4th and 8th ranks or 3rd and 9th ranks averaged to the 6th central rank, should be preferred over the classic one-measurement estimation. The modified versions are characterised by an improved accuracy (about 25%) without statistically significant bias and measurement costs comparable to the classic Weise method.
      PubDate: 2015-07-27
      DOI: 10.3390/f6082545
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2560-2570: Chewing up the Wood-Wide Web: Selective
           Grazing on Ectomycorrhizal Fungi by Collembola

    • Authors: Clarisse Kanters, Ian Anderson, David Johnson
      Pages: 2560 - 2570
      Abstract: The mycelia of some symbiotic ectomycorrhizal fungi form extensive networks—the so called “wood-wide web”—that have key roles in biogeochemical cycling. By interacting with myriad soil organisms such as collembola, the fungi directly affect the functioning of above- and below-ground multitrophic interactions in ecosystems. Here we tested whether the grazing activities of collembola affected the growth of ectomycorrhizal fungi in single or mixed species axenic cultures, and their impact on ectomycorrhizal diversity in litterbags in the field. We also used 14CO2 pulse-labelling to test the effects of collembola on respiratory losses of recent plant assimilate from external mycelium of ectomycorrhizal fungi in symbiosis with Scots pine or birch. We found that the effects of collembola varied across species, and caused a significant reduction in the amount of 14CO2 released from external mycorrhizal mycelium from three of the eight species combinations but increased it in one. Selective grazing also significantly affected the community structure of ectomycorrhizal fungi. Our findings demonstrate the importance of collembola in regulating ectomycorrhizal fungal diversity and activity and below-ground pathways of carbon flow.
      PubDate: 2015-07-28
      DOI: 10.3390/f6082560
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2571-2587: Wood Decay Fungi Restore Essential
           Calcium to Acidic Soils in Northern New England

    • Authors: Walter Shortle, Kevin Smith
      Pages: 2571 - 2587
      Abstract: The depletion of root-available calcium in northern forests soils exposed to decades of increased acid deposition adversely affects forest health and productivity. Laboratory studies indicated the potential of wood-decay fungi to restore lost calcium to the rooting zone of trees. This study reports changes in concentrations of Ca, Mg, and K during decay of sapwood of spruce, maple, hemlock, and birch at two locations in northern New England, USA. Concentrations of exchangeable Ca, Mg, and Al in decayed wood residues after 10 and 12 years of ground contact were also compared. Significant loss of mass indicated by decreasing wood density occurred after two to eight years in conifers and after only two years in hardwoods. A significant gain in wood K was observed at two years, but the gain was not sustained. A significant gain in Ca concentration occurred by six years and that gain was sustained for 12 years. Concentrations of Mg varied. No significant difference in exchangeable Ca concentration was observed between decayed wood residue of spruce and maple and the forest floor. However, decayed wood residue had a much lower molar Al/Ca ratio, a conditional characteristic of sites with high root-available Ca.
      PubDate: 2015-07-29
      DOI: 10.3390/f6082571
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2588-2607: Importance of Arboreal Cyanolichen
           Abundance to Nitrogen Cycling in Sub-Boreal Spruce and Fir Forests of
           Central British Columbia, Canada

    • Authors: Ania Kobylinski, Arthur Fredeen
      Pages: 2588 - 2607
      Abstract: The importance of N2-fixing arboreal cyanolichens to the nitrogen (N)-balance of sub-boreal interior hybrid spruce (Picea glauca × engelmannii) and subalpine fir (Abies lasiocarpa) forests was examined at field sites in central BC, Canada. Host trees were accessed by a single-rope climbing technique and foliage as well as arboreal macrolichen functional groups were sampled by branch height in eight random sample trees from each of two high (High Cyano) and two low (Low Cyano) cyanolichen abundance sites for a total of 32 sample trees. Natural abundances of stable isotopes of N (15N, 14N) and carbon (13C, 12C) were determined for aggregate host tree and epiphytic lichen samples, as well as representative samples of upper organic and soil horizons (Ae and Bf) from beneath host trees. As expected, N2-fixing cyanolichens had 2–6-fold greater N-contents than chlorolichens and a δ15N close to atmospheric N2, while foliage and chlorolichens were more depleted in 15N. By contrast, soils at all trees and sites were 15N-enriched (positive δ15N), with declining (not significant) δ15N with increased tree-level cyanolichen abundance. Lichen functional groups and tree foliage fell into three distinct groups with respect to δ13C; the tripartite cyanolichen Lobaria pulmonaria (lightest), host-tree needles (intermediate), and bipartite cyanolichens, hair (Alectoria and Bryoria spp.) and chlorolichens (heaviest). Branch height of host trees was an effective predictor of needle δ13C. Our results showed a modest positive correlation between host tree foliage N and cyanolichen abundance, supporting our initial hypothesis that higher cyanolichen abundances would elevate host tree foliar N. Further study is required to determine if high cyanolichen abundance enhances host tree and/or stand-level productivity in sub-boreal forests of central BC, Canada.
      PubDate: 2015-07-31
      DOI: 10.3390/f6082588
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2608-2630: Enriching ALS-Derived Area-Based
           Estimates of Volume through Tree-Level Downscaling

    • Authors: Piotr Tompalski, Nicholas Coops, Joanne White, Michael Wulder
      Pages: 2608 - 2630
      Abstract: Information on individual tree attributes is important for sustainable management of forest stands. Airborne Laser Scanning (ALS) point clouds are an excellent source of information for predicting a range of forest stand attributes, with plot and single tree volume being among the most important. Two approaches exist for estimating volume: area-based approach (ABA) and individual tree detection (ITD). The ABA is now routinely applied in operational forestry applications, and results in generalized plot- or stand-level attribute predictions. Alternatively, ITD-based estimates provide detailed information for individual trees, but are typically biased due to challenges associated with individual tree detection. In this study, we applied an ABA to estimate tree counts and individual tree volumes by downscaling plot-level predictions of total volume derived using ALS data in a highly productive and complex coastal temperate forest environment in British Columbia, Canada, characterized by large volumes and multi-species and multi-age stand structures. To do so, a two-parameter Weibull probability density function (PDF) was used to describe the within-plot tree volume distribution. The ABA approach was then used to model the total plot volume and the two Weibull PDF parameters. Next, the parameters were used to calculate mean tree volume and derive the number of trees and the individual tree volume distribution. Tree count estimates were minimally biased with RMSE of 149 trees·ha−1 or 24.4%. The volume distributions showed good agreement with reference data (mean Reynold’s error index = 71.7). We conclude that the approach was suitable for enriching ABA-derived forest stand attributes in the majority of the studied forest stands; however the accuracy was lower in multi-layered stands that had a multimodal individual tree volume distribution.
      PubDate: 2015-07-31
      DOI: 10.3390/f6082608
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2631-2654: Leaf Area Prediction Using Three
           Alternative Sampling Methods for Seven Sierra Nevada Conifer Species

    • Pages: 2631 - 2654
      Abstract: Prediction of projected tree leaf area using allometric relationships with sapwood cross-sectional area is common in tree- and stand-level production studies. Measuring sapwood is difficult and often requires destructive sampling. This study tested multiple leaf area prediction models across seven diverse conifer species in the Sierra Nevada of California. The best-fit whole tree leaf area prediction model for overall simplicity, accuracy, and utility for all seven species was a nonlinear model with basal area as the primary covariate. A new non-destructive procedure was introduced to extend the branch summation approach to leaf area data collection on trees that cannot be destructively sampled. There were no significant differences between fixed effects assigned to sampling procedures, indicating that data from the tested sampling procedures can be combined for whole tree leaf area modeling purposes. These results indicate that, for the species sampled, accurate leaf area estimates can be obtained through partially-destructive sampling and using common forest inventory data.
      PubDate: 2015-07-31
      DOI: 10.3390/f6082631
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2655-2677: Smallholders’ Tree Planting
           Activity in the Ziro Province, Southern Burkina Faso: Impacts on
           Livelihood and Policy Implications

    • Authors: Daniel Etongo, Ida Djenontin, Markku Kanninen, Kalame Fobissie
      Pages: 2655 - 2677
      Abstract: Climate variability and change significantly affect smallholder farmers’ food security and livelihoods in sub-Saharan Africa. Tree planting is one of the measures promoted by development programs to mitigate and adapt to climate change. Tree planting is also believed to positively contribute to livelihoods. This paper examines factors influencing smallholders’ tree planting activities in four villages in the Ziro province, Southern Burkina Faso. Furthermore, it analyses the challenges encountered and willingness to continue tree planting under current tenure arrangements. The data was obtained through key informants, household interviews, focus group discussions, and field observations. Results indicate that the majority of farmers interviewed planted Mangifera indica (50%), Anacardium occidentale (32%) and Moringa oleifera (30%). In a number of trees planted, Eucalyptus camaldulensis, Mangifera indica and Anacardium occidentale dominated. Tree planters were mainly farmers who held large and old farm areas, were literate and relatively wealthy, had favorable attitudes toward tree planting, and with considerable years of participation in a farmers’ group. The main reasons for planting trees included income generation from the sale of tree products, access to markets and local support for tree planting. Preference for agriculture, tenure insecurity and lack of sufficient land were the main reasons cited for not planting trees. Farm households that were relatively poor, had smaller workforces and smaller farm sizes were not willing to continue tree planting. To effectively engage farmers in tree planting and to make it more attractive, policies are needed that address tenure insecurity for migrants, enable better access to markets, and support fair pricing structures for wood and other tree resources.
      PubDate: 2015-07-31
      DOI: 10.3390/f6082655
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2678-2702: Response of Boreal Jack Pine (Pinus
           banksiana Lamb.) Stands to a Gradient of Commercial Thinning Intensities,
           with and without N Fertilization

    • Authors: Julien Moulinier, Suzanne Brais, Brian Harvey, Ahmed Koubaa
      Pages: 2678 - 2702
      Abstract: This study examines tree and stand response to a gradient of commercial thinning intensities and nitrogen fertilization (200 kg N ha−1) in nine jack pine (Pinus banksiana) stands of Eastern Canada over a period of 14 years. Thinning intensity ranged from 0% basal area removal in control plots to 64% in thinned plots. Tree diameter increment, absolute and relative volume increment and mean volume increased with thinning intensity and were higher in fertilized plots. Individual tree response depended on tree diameter, with smallest trees exhibiting highest relative volume increment to thinning intensity. Stand basal area increment was positively associated to initial stand basal area and negatively to stand age. In thinned and fertilized plots, stand volume increment was higher and natural mortality lower than in fertilized only and unfertilized control plots over the 5–14 year period after thinning. However, the positive effect of fertilization on tree volume increment decreased with thinning intensity. Despite positive individual tree growth responses to thinning and fertilization, residual stand volume increment decreased with increased thinning intensity in both fertilized and unfertilized plots. While total cumulative stand volume (harvested + residual) also decreased with thinning intensity in unfertilized plots, comparable total volumes were observed in fertilized + thinned and unthinned control plots. Nitrogen fertilization in the years following commercial thinning enhanced the benefit of thinning on these relatively poor sites by increasing tree diameter growth, lowering mortality, and increasing total stand merchantable volume compared to unfertilized thinned stands.
      PubDate: 2015-07-31
      DOI: 10.3390/f6082678
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2703-2718: Change of Soil Carbon Fractions and
           Water-Stable Aggregates in a Forest Ecosystem Succession in South China

    • Authors: Huimin Xiang, Lingling Zhang, Dazhi Wen
      Pages: 2703 - 2718
      Abstract: In order to evaluate the dynamics of carbon storage during forest succession and explore the significance of water relations and soil stability in forest environments, a study was conducted in 2011. This study investigated the dynamics of soil organic carbon (SOC) fractions and its protection through aggregation along the successional forests. An experiment in South China examined pine forest (PF), pine and broadleaved mixed forest (PBMF), and monsoon evergreen broadleaf forest (MEBF), which represent the early, middle, and advanced succession stages, respectively. Soil was sampled at 0–15, 15–30, 30–45, and 45–60 cm depths. We analyzed active, slow, and passive organic carbon, as well as particulate organic matter carbon (POM-C) and nitrogen (POM-N), and measured the weight and concentration of water-stable aggregates in four classes (>2000 μm, 250–2000 μm, 53–250 μm, and <53 μm). The results suggested that various carbon fractions and the percentage of active and passive carbon to total organic carbon (TOC) increased with forest succession. The percentage of water-stable aggregates in >2000 μm (0–15 cm and 15–30 cm) and <53 μm (45–60 cm) in MEBF was significantly higher than in PBMF and PF. The SOC content of all size classes of water-stable aggregates in 0–45 cm were significantly increased with forest succession. In conclusion, forest succession contributed to the accumulation of carbon storage, and the increasing percentage of silt- and clay-size (<53 μm) fraction improved the stability of soil organic matter (SOM).
      PubDate: 2015-08-05
      DOI: 10.3390/f6082703
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2719-2738: Benthic Collector and Grazer Communities
           Are Threatened by Hemlock Woolly Adelgid-Induced Eastern Hemlock Loss

    • Authors: Joshua Adkins, Lynne Rieske
      Pages: 2719 - 2738
      Abstract: Eastern hemlock (Tsuga canadensis (L.) is a foundation species in eastern North America where it is under threat from the highly invasive, exotic hemlock woolly adelgid (Adelges tsugae). Eastern hemlock is especially important in riparian areas of Central and Southern Appalachia, so we compared the spatial and temporal composition of benthic collector-gatherers, collector-filterers, and grazers in headwater streams with hemlock-dominated riparian vegetation to those with deciduous tree-dominated riparian vegetation to evaluate the extent to which adelgid-induced hemlock loss could influence composition and abundance of these two functional feeding groups. We found differences in benthic invertebrate abundance and family-level diversity based on riparian vegetation and sampling approach, and, often, riparian vegetation significantly interacted with location or season. Collector-gatherers and grazers were more abundant in eastern hemlock streams in the summer, when hemlock litter is readily available and deciduous litter is relatively sparse. Riparian eastern hemlock appears to exert considerable influence on benthic invertebrate functional feeding group composition in headwater stream communities, as expected with a foundation species. With the loss of eastern hemlock due to adelgid-induced mortality, we should expect to see alterations in spatial and temporal patterns of benthic invertebrate abundance and diversity, with potential consequences to both benthic and terrestrial ecosystem function.
      PubDate: 2015-08-06
      DOI: 10.3390/f6082719
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2739-2761: Identification of Nine
           Pathotype-Specific Genes Conferring Resistance to Fusiform Rust in
           Loblolly Pine (Pinus taeda L.)

    • Authors: Henry Amerson, C. Nelson, Thomas Kubisiak, E. Kuhlman, Saul Garcia
      Pages: 2739 - 2761
      Abstract: Nearly two decades of research on the host-pathogen interaction in fusiform rust of loblolly pine is detailed. Results clearly indicate that pathotype-specific genes in the host interacting with pathogen avirulence cause resistance as defined by the non-gall phenotype under favorable environmental conditions for disease development. In particular, nine fusiform rust resistance genes (Fr genes) are described here including the specific methods to determine each and their localization on the reference genetic map of loblolly pine. Understanding how these and other apparent Fr genes in loblolly pine and other rust-susceptible pines impact resistance screening, parental and progeny selection, and family and clonal deployment is an important area in forest genetics research and operational tree breeding. The documentation of these Fr genes is a key piece of information towards gaining that understanding and ultimately improving breeding and deployment strategies.
      PubDate: 2015-08-07
      DOI: 10.3390/f6082739
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2762-2784: Influence of Low Frequency Variability

    • Authors: Robin Thorne, M. Arain
      Pages: 2762 - 2784
      Abstract: Carbon, water and energy exchanges between forests and the atmosphere depend upon seasonal dynamics of both temperature and precipitation, which are influenced by low frequency climate oscillations such as: El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Arctic Oscillation (AO), Eastern Pacific Oscillation (EPO) and the Pacific-North American (PNA). This study investigated the influence of climate oscillations on the local climate and carbon fluxes in a 75-year old temperate pine (Pinus strobus L.) forest, near Lake Erie in southern Ontario, Canada. Analyses indicated mean winter temperatures were correlated to NAO, AO and EPO, total winter precipitation was influenced by PNA and AO, while total snowfall was correlated with PNA and ENSO. These impacts influenced carbon dynamics of the forest during the winter and spring seasons. The EPO had a significant inverse correlation with winter and spring carbon fluxes, while the Pacific Decadal Oscillation (PDO) was significantly correlated with winter respiration. In 2012, an extreme warm event linked to climate oscillations raised temperatures and resulted in a large release of carbon from the forest due to higher ecosystem respiration. As low frequency climate oscillations are important drivers of extreme weather events, affecting their intensity, frequency and spatial patterns, they can cause large changes in carbon exchanges in forest ecosystems in the northeastern parts of North America.
      PubDate: 2015-08-12
      DOI: 10.3390/f6082762
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2785-2798: Exploration of Optimal Agricultural
           Practices and Seedling Types for Establishing Poplar Plantations

    • Pages: 2785 - 2798
      Abstract: Controlling competing vegetation during early growth is one of the most important practices for the successful establishment of poplar plantations. Today, most poplar plantations in temperate regions are established on abandoned marginal agricultural land where competing vegetation is usually present during the first years after planting. Thus, the objective of this study was to examine how the growth of two kinds of poplar planting materials, un-rooted cuttings and bare-rooted seedlings was influenced by different vegetation control and soil preparation practices. Across treatments, un-rooted cuttings grew more rapidly than the bare-rooted seedlings. Our results also show that mulching with a degradable carpet or permanent polyethylene plastic increased seedling growth to a similar extent and more strongly in the cases of no treatment (in control plots). In addition, the results suggest that soil preparation in the mulched area favored seedling growth, but this effect was restricted to the first year after planting. These findings indicate that optimal practices for establishing poplar plantations on former agricultural land include planting un-rooted cuttings in prepared soil and mulching.
      PubDate: 2015-08-13
      DOI: 10.3390/f6082785
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2799-2819: Juvenile Southern Pine Response to
           Fertilization Is Influenced by Soil Drainage and Texture

    • Authors: Timothy Albaugh, Thomas Fox, H. Allen, Rafael Rubilar
      Pages: 2799 - 2819
      Abstract: We examined three hypotheses in a nutrient dose and application frequency study installed in juvenile (aged 2–6 years old) Pinus stands at 22 sites in the southeastern United States. At each site, eight or nine treatments were installed where nitrogen was applied at different rates (0, 67, 134, 268 kg ha−1) and frequencies (0, 1, 2, 4 and 6 years) in two or four replications. Phosphorus was applied at 0.1 times the nitrogen rate and other elements were added as needed based on foliar nutrient analysis to insure that nutrient imbalances were not induced with treatment. Eight years after treatment initiation, the site responses were grouped based on texture and drainage characteristics: soil group 1 consisted of poorly drained soils with a clayey subsoil, group 2 consisted of poorly to excessively drained spodic soils or soils without a clay subsoil, and group 3 consisted of well-drained soils with a clayey subsoil. We accepted the first hypothesis that site would be a significant factor explaining growth responses. Soil group was also a significant factor explaining growth response. We accepted our second hypothesis that the volume growth-cumulative dose response function was not linear. Volume growth reached an asymptote in soil groups 1 and 3 between cumulative nitrogen doses of 300–400 kg ha−1. Volume growth responses continued to increase up to 800 kg ha−1 of cumulatively applied nitrogen for soil group 2. We accepted our third hypothesis that application rate and frequency did not influence the growth response when the cumulative nitrogen dose was equivalent. There was no difference in the growth response for comparisons where a cumulative nitrogen dose of 568 kg ha−1 was applied as 134 kg ha−1 every two years or as 269 kg ha−1 every four years, or where 269 kg ha−1 of nitrogen was applied as four applications of 67 kg ha−1 every two years or as two applications of 134 kg ha−1 every four years. Clearly, the sites examined here were limited by nitrogen and phosphorus, and applications of these elements to young stands effectively ameliorated these limitations. However, there were differences in the response magnitude that were related to soil texture and drainage. Juvenile fertilizer applications resulted in high stocking levels early in the rotation; this condition should be considered when undertaking juvenile fertilization programs.
      PubDate: 2015-08-14
      DOI: 10.3390/f6082799
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2820-2835: Nitrogen Nutrition of Trees in Temperate
           Forests—The Significance of Nitrogen Availability in the Pedosphere
           and Atmosphere

    • Authors: Heinz Rennenberg, Michael Dannenmann
      Pages: 2820 - 2835
      Abstract: Nitrogen (N) is an essential nutrient that is highly abundant as N2 in the atmosphere and also as various mineral and organic forms in soils. However, soil N bioavailability often limits the net primary productivity of unperturbed temperate forests with low atmospheric N input. This is because most soil N is part of polymeric organic matter, which requires microbial depolymerization and mineralization to render bioavailable N forms such as monomeric organic or mineral N. Despite this N limitation, many unfertilized forest ecosystems on marginal soil show relatively high productivity and N uptake comparable to agricultural systems. The present review article addresses the question of how this high N demand is met in temperate forest ecosystems. For this purpose, current knowledge on the distribution and fluxes of N in marginal forest soil and the regulation of N acquisition and distribution in trees are summarized. The related processes and fluxes under N limitation are compared with those of forests exposed to high N loads, where chronic atmospheric N deposition has relieved N limitation and caused N saturation. We conclude that soil microbial biomass is of decisive importance for nutrient retention and provision to trees both in high and low N ecosystems.
      PubDate: 2015-08-14
      DOI: 10.3390/f6082820
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2836-2852: Assessing Douglas-Fir Seedling
           Establishment Using Two Modified Forestry Reclamation Approaches in the
           Pacific Northwest

    • Authors: Colton Miller, Grace King, Yurong Liu, Robert Harrison, Eric Turnblom, Darlene Zabowski
      Pages: 2836 - 2852
      Abstract: The Forestry Reclamation Approach uses uncompacted, mounded spoils to reforest mined-land and has been successful in hardwood forests in the Appalachian region. A surface coalmine reclamation site in the Pacific Northwest was used to compare the site’s standard reclamation approach (Reference) with a modified version of the Forestry Reclamation Approach (FRA) along with a modified FRA treatment that also incorporated an amendment of bottom ash from the coal burning power plant on-site (FRA + Ash). Survival and growth were followed for three growing seasons in bareroot and container Douglas-fir seedlings. Soil characteristics and understory cover were also assessed. Considerable variation in microsite characteristics was observed in the study area. Container seedlings did not improve survival compared to bareroot seedlings. In the soil reclamation treatments, seedling survival was significantly higher in FRA + Ash treatments compared to FRA and Reference treatments at the end of the second growing season. Survival declined in each year of the study, but the order of treatment effectiveness did not change. Relativized growth increment was significantly higher in the FRA treatment compared to both the Reference and FRA + Ash treatments during the third growing season. Understory cover was established after three years, but varied substantially across the study area.
      PubDate: 2015-08-21
      DOI: 10.3390/f6082836
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2853-2878: Evaluations of Landscape Locations along
           Trails Based on Walking Experiences and Distances Traveled in the Akasawa
           Forest Therapy Base, Central Japan

    • Authors: Tong Zhang, Songqiu Deng, Qianqian Ma, Kunihiro Sasaki
      Pages: 2853 - 2878
      Abstract: Forest planners are interested not only in forest spaces that visitors prefer but also in the preferred spatial arrangements of landscape features. In this study, we aimed to clarify walkers’ evaluations of four landscape locations composed of various scenic features in various spatial arrangements along forest walking routes. We also analyzed the trends, differences, and common features associated with different walking distances and experiences. The results are summarized as follows: (1) The walkers’ evaluations changed depending on the elements of the scene they observed and the spatial arrangements of those elements. The visitors preferred silent environments in forest spaces to the sounds of a stream. Meanwhile, they appreciated a good view in an open area. (2) The length of a walk prior to visiting a location on a route affected walkers’ evaluations of that location. For example, a special landscape feature was more positively rated by the respondents who visited the location late in their walks than those in the early and middle walking stages. However, the early-passage walkers were more pleased by touching natural objects such as rocks and large trees than those later in their walks. (3) Analysis revealed that the ratings of certain parameters differed according to the route taken to a location, whereas other ratings remain unchanged. Consequently, we must consider the effects of spatial properties of scenic factors on people’s perceptions in forest planning. (4) Walkers provided similar ratings on three parameters within forest landscapes—“Open feeling”, “Regular landscape” and “Natural” feel—even in the middle and near the end of their walks. Conversely, locations with water elements led to variations in parameter ratings that were maintained until the end of a person’s walk. Based on these results, we suggest that positive walking experiences can be maintained by considering the open feeling, regularity, and natural landscape in all three passage stages in planning walking routes.
      PubDate: 2015-08-21
      DOI: 10.3390/f6082853
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2879-2896: Impact of European Union Timber
           Regulation on Forest Certification Strategies in the Finnish Wood Industry
           Value Chain

    • Authors: Jani Holopainen, Anne Toppinen, Sini Perttula
      Pages: 2879 - 2896
      Abstract: The aim of this explorative study is to find out how the EU Timber Regulation (EUTR) has affected the forest and chain of custody (CoC) certification strategies and practices among the Finnish wood industry companies. We are especially interested to find out whether more integrated strategies and collaborative networks have emerged for enhanced communications throughout the industry value chains. This qualitative interview study included both EUTR ex ante and ex post analysis, based on three rounds of managerial and expert interviews during 2011–2015. The results indicate that the EUTR appears to have enforced the supplier–client relations in the Finnish wood industry value chain. The sector still lacks integrated communication strategies with better understanding of customer and stakeholder values, which could contribute to more cohesive communication and marketing efforts reflecting the values of the whole industry. The certification practices are fairly spontaneously implemented following the traditional industry culture, which is not supportive of innovations and gaining competitive advantages in the broader material markets. Furthermore, the existence of two parallel forest certificates (Forest Stewardship Council (FSC) and Programme for the Endorsement of Forest Certification (PEFC)) seems to hamper the effective communication and building of an image of sustainable wood products among customers and end consumers, groups that are also exposed to more general environmental communication, e.g., in the building material markets.
      PubDate: 2015-08-24
      DOI: 10.3390/f6082879
      Issue No: Vol. 6, No. 8 (2015)
  • Forests, Vol. 6, Pages 2405-2423: Adapting Free, Prior, and Informed
           Consent (FPIC) to Local Contexts in REDD+: Lessons from Three Experiments
           in Vietnam

    • Authors: Thuy Pham, Jean-Christophe Castella, Guillaume Lestrelin, Ole Mertz, Dung Le, Moira Moeliono, Tan Nguyen, Hien Vu, Tien Nguyen
      Pages: 2405 - 2423
      Abstract: Free, prior, and informed consent (FPIC) is a means of ensuring that people’s rights are respected when reducing emissions from deforestation and forest degradation, and enhancing forest carbon stocks (REDD+) projects are established in developing countries. This paper examines how FPIC has been applied in three projects in Vietnam and highlights two key lessons learnt. First, as human rights and democracy are seen as politically sensitive issues in Vietnam, FPIC is likely to be more accepted by the government if it is built upon the national legal framework on citizen rights. Applying FPIC in this context can ensure that both government and citizen’s interests are achieved within the permitted political space. Second, FPIC activities should be seen as a learning process and designed based on local needs and preferences, with accountability of facilitators, two-way and multiple communication strategies, flexibility, and collective action in mind.
      PubDate: 2015-07-15
      DOI: 10.3390/f6072405
      Issue No: Vol. 6, No. 7 (2015)
  • Forests, Vol. 6, Pages 2424-2449: Comparing the Costs and Revenues of
           Transformation to Continuous Cover Forestry for Sitka Spruce in Great

    • Authors: Owen Davies, Gary Kerr
      Pages: 2424 - 2449
      Abstract: Recently continuous cover forestry (CCF) has become an accepted approach to forest management in Britain, but uncertainty about its economic consequences may be a barrier to its wider use. A study was carried out to examine the costs and revenues of transforming a stand of Sitka spruce (Picea sitchensis (Bong.) Carr.) to CCF. The main conclusion is that transformation to CCF need not be more costly than clearfelling and replanting if natural regeneration is successful and the aim is to produce a simple canopy structure. The long-term value of transformation to a more complex canopy structure, with three or more strata, is lower and the extra costs need to be justified in terms of management objectives. The main output from the study is an analysis spreadsheet that empowers practitioners and policy makers to investigate the effects of costs, revenues and discount rates on estimates of net present value over 20 years, 100 years and in perpetuity, to suit local conditions. This paper summarises the method and results of the study in a British context, sets these in a wider international context, and considers the merits, applications and possible further developments of the approach.
      PubDate: 2015-07-15
      DOI: 10.3390/f6072424
      Issue No: Vol. 6, No. 7 (2015)
  • Forests, Vol. 6, Pages 2450-2468: Occurrence of Density-Dependent Height
           Repression within Jack Pine and Black Spruce Populations

    • Authors: Peter Newton
      Pages: 2450 - 2468
      Abstract: The objective of this study was to investigate the occurrence of density-dependent height relationships in jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) B.S.P.) populations. After assessing and ruling out the presence of consequential spatial correlation effects, the analysis consisted of analyzing the relationship between mean dominant height and initial planting density within 28 Nelder plots located in the central portion of the Canadian Boreal Forest Region. Employing remeasurement data obtained at periodic intervals (16, 20 and 40–41 years post-establishment) across a stand density gradient ranging from a minimum of 1425 stems/ha to a maximum of 28,621 stems/ha, graphical and simple linear regression analyses were used to quantify the stand height–density relationship by species, plot and measurement year. The results indicated the presence of density-dependent effects on height development for both species: 65% of the 83 jack pine relationships and 89% of the 27 black spruce relationships had significant (p ≤ 0.05) and negative slope values. In regards to jack pine for which the data permitted, the occurrence and magnitude of the observed height repression effect increased over time. The asymptotic height repression effect for jack pine was 24% greater than that for black spruce. The results are discussed within the context of the applicability of the density-independent height growth assumption and potential implications for site quality estimation and thinning response modeling.
      PubDate: 2015-07-16
      DOI: 10.3390/f6072450
      Issue No: Vol. 6, No. 7 (2015)
  • Forests, Vol. 6, Pages 2469-2483: Molecular Identification of Phytoplasmas
           Infecting Diseased Pine Trees in the UNESCO-Protected Curonian Spit of

    • Authors: Deividas Valiunas, Rasa Jomantiene, Algirdas Ivanauskas, Indre Urbonaite, Donatas Sneideris, Robert Davis
      Pages: 2469 - 2483
      Abstract: Although mainly known as pathogens that affect angiosperms, phytoplasmas have recently been detected in diseased coniferous plants. In 2008–2014, we observed, in the Curonian Spit of Western Lithuania and in forests of Southern Lithuania (Varena district), diseased trees of Scots pine (Pinus sylvestris) and mountain pine (Pinus mugo) with unusual symptoms similar to those caused by phytoplasmas. Diseased trees exhibited excessive branching, dwarfed reddish or yellow needles, dried shoots and ball-like structures. restriction fragment length polymorphism (RFLP) and nucleotide sequence analysis of 16S rRNA gene fragments revealed that individual trees were infected by Candidatus (Ca.) Phytoplasma pini-related strains (members of phytoplasma subgroup 16SrXXI-A) or by Ca. Phytoplasma asteris-related strains (subgroup 16SrI-A). Of the nearly 300 trees that were sampled, 80% were infected by phytoplasma. Ninety-eight percent of the positive samples were identified as Ca. Phytoplasma pini-related strains. Strains belonging to subgroup 16SrI-A were identified from only few trees. Use of an additional molecular marker, secA, supported the findings. This study provides evidence of large-scale infection of Pinus by Ca. Phytoplasma pini in Lithuania, and it reveals that this phytoplasma is more widespread geographically than previously appreciated. This is also the first report of phytoplasma subgroup 16SrI-A in pine trees.
      PubDate: 2015-07-17
      DOI: 10.3390/f6072469
      Issue No: Vol. 6, No. 7 (2015)
  • Forests, Vol. 6, Pages 2484-2504: Drivers of CO2 Emission Rates from Dead
           Wood Logs of 13 Tree Species in the Initial Decomposition Phase

    • Pages: 2484 - 2504
      Abstract: Large dead wood is an important structural component of forest ecosystems and a main component of forest carbon cycles. CO2 emissions from dead wood can be used as a proxy for actual decomposition rates. The main drivers of CO2 emission rates for dead wood of temperate European tree species are largely unknown. We applied a novel, closed chamber measurement technique to 360 dead wood logs of 13 important tree species in three regions in Germany. We found that tree species identity was with 71% independent contribution to the model (R2 = 0.62) the most important driver of volume-based CO2 emission rates, with angiosperms having on average higher rates than conifers. Wood temperature and fungal species richness had a positive effect on CO2 emission rates, whereas wood density had a negative effect. This is the first time that positive fungal species richness—wood decomposition relationship in temperate forests was shown. Certain fungal species were associated with high or low CO2 emission rates. In addition, as indicated by separate models for each tree species, forest management intensity, study region, and the water content as well as C and N concentration of dead wood influenced CO2 emission rates.
      PubDate: 2015-07-20
      DOI: 10.3390/f6072484
      Issue No: Vol. 6, No. 7 (2015)
  • Forests, Vol. 6, Pages 3809-3827: Intra-Annual Xylem Growth of Larix
           principis-rupprechtii at Its Upper and Lower Distribution Limits on the
           Luyashan Mountain in North-Central China

    • Authors: Yuan Jiang, Yiping Zhang, Yuanyuan Guo, Muyi Kang, Mingchang Wang, Biao Wang
      Pages: 3809 - 3827
      Abstract: Altitude-related climatic factors, especially temperature, are important factors that affect tree growth in mountain forest ecosystems. The aims of this study were to estimate the intra-annual radial growth differences of Larix principis-rupprechtii (L. principis-rupprechtii) between its upper and lower distribution limits, at 2740 and 2040 m a.s.l, respectively. Dynamics of xylem growth were observed by collecting microcore samples weekly during the 2011 growth season. The result indicated that different strategies were adopted at the two selected sites. Trees at the upper distribution limit adopted an “intensive strategy” with higher maximum growth rates (0.69 cell·day−1) within a shorter duration of 95 days, producing 21 new tracheids. By contrast, trees at the lower distribution limit exhibited an “extensive strategy” with lower maximum growth rates (0.53 cell·day−1) over a longer duration of 135 days, producing 50 tracheids. The soil temperature was probably the main factor limiting the onset of cambial activity for L. principis-rupprechtii, its daily mean thresholds for onset were 0 °C and 1.4 °C at the upper and lower distribution limits, respectively. These results indicate that L. principis-rupprechtii is able to adjust its xylem growth according to environmental conditions.
      PubDate: 2015-10-29
      DOI: 10.3390/f6113809
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3828-3846: A Bayesian Spatial Model Highlights
           Distinct Dynamics in Deforestation from Coca and Pastures in an Andean
           Biodiversity Hotspot

    • Pages: 3828 - 3846
      Abstract: The loss of tropical forests has continued in recent decades despite wide recognition of their importance to maintaining biodiversity. Here, we examine the conversion of forests to pastures and coca crops (illicit activity) on the San Lucas Mountain Range, Colombia for 2002–2007 and 2007–2010. Land use maps and biophysical variables were used as inputs to generate land use and cover change (LUCC) models using the DINAMICA EGO software. These analyses revealed a dramatic acceleration of the pace of deforestation in the region, with rates of conversion from forest to pasture doubling from the first to the second period. Altitude, distance to other crops, and distance to rivers were the primary drivers of deforestation. The influence of these drivers, however, differed markedly depending on whether coca cultivation or pastures replaced forest. Conversion to coca was more probable farther from other crops and from settlements. In contrast, proximity to other crops and to settlements increased conversion to pasture. These relationships highlight the different roles of coca and pastures in forest loss, with coca tending to open up new forest frontiers, and pastures tending to consolidate agricultural expansion and urban influence. Large differences between LUCC processes for each period suggest highly dynamic changes, likely associated with shifting underlying causes of deforestation. These changes may relate to shifts in demand for illicit crops, land, or mining products; however, the data to test these hypotheses are currently lacking. More frequent and detailed monitoring is required to guide actions to decrease the loss of forest in this highly vulnerable biodiversity hotspot in the Northern Andes.
      PubDate: 2015-10-30
      DOI: 10.3390/f6113828
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3847-3867: Does Tree Architectural Complexity
           Influence the Accuracy of Wood Volume Estimates of Single Young Trees by
           Terrestrial Laser Scanning?

    • Pages: 3847 - 3867
      Abstract: Accurate estimates of the wood volume or biomass of individual trees have gained considerable importance in recent years. The accuracy of wood volume estimation by terrestrial laser scanning (TLS) point cloud data may differ between individual trees due to species-specific differences in tree architecture. We selected three common and ecologically important central European deciduous tree species, which differ considerably in tree architectural complexity in early ontogenetic stages: Acer pseudoplatanus (simple), Sorbus aucuparia (intermediate) and Betula pendula (complex). We scanned six single young trees for each species (18 trees in total) under optimal scan conditions (single tree stand, leafless state, four scanning positions, high resolution). TLS-based volume estimates were derived for the total tree as well as for the two compartments; trunk and branches, using a voxel-based bounding box method. These estimates were compared with highly accurate xyolmetric (water displacement) volume measurements. Coefficients of determination between xylometric measurements and bounding box estimates were very high for total trees (R2adj = 0.99), trunks (R2adj = 0.99), and high for branches (R2adj = 0.78). The accuracy of estimations for total tree and trunk volume was highly similar among the three tree species. In contrast, significant differences were found for branch volume estimates: the accuracy was very high for Sorbus aucuparia, intermediate for Betula pendula, and low for Acer pseudoplatanus. A stepwise multiple regression showed that the accuracy of branch volume estimates was negatively related to the number of the first-order branches within diameter sizes of D ≤ 5 mm and crown surface area (R2adj = 0.61). We conclude that the accuracy in total tree and trunk volume estimates was not affected by the studied types of tree architectural complexity. The impact of the structural variability of branches and occlusion by branches was, thus, not as high as expected. In contrast, the accuracy of branch volume estimates was strongly influenced by tree architectural complexity, though not in a simple way. Because underestimations originated from different sources, the accuracy of branch volume estimates cannot be directly derived from the degree of architectural complexity. These results imply that the voxel-based bounding box method provides highly accurate total tree and trunk volume estimates, whereas further research is needed to improve branch volume estimation for young trees of different architectural types.
      PubDate: 2015-10-30
      DOI: 10.3390/f6113847
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3868-3881: Outbreak of Phoracantha semipunctata in
           Response to Severe Drought in a Mediterranean Eucalyptus Forest

    • Authors: Stephen Seaton, George Matusick, Katinka Ruthrof, Giles Hardy
      Pages: 3868 - 3881
      Abstract: Extreme climatic events, including droughts and heatwaves, can trigger outbreaks of woodboring beetles by compromising host defenses and creating habitat conducive for beetle development. As the frequency, intensity, and duration of droughts are likely to increase in the future, beetle outbreaks are expected to become more common. The combination of drought and beetle outbreaks has the potential to alter ecosystem structure, composition, and function. Our aim was to investigate a potential outbreak of the native Eucalyptus longhorned borer, Phoracantha semipunctata (P. semipunctata), following one of the most severe droughts on record in the Northern Jarrah Forest of Southwestern Australia. Beetle damage and tissue moisture were examined in trees ranging from healthy to recently killed. Additionally, beetle population levels were examined in adjacent forest areas exhibiting severe and minimal canopy dieback. Severely drought-affected forest was associated with an unprecedented outbreak of P. semipunctata, with densities 80 times higher than those observed in surrounding healthier forest. Trees recently killed by drought had significantly lower tissue moisture and higher feeding damage and infestation levels than those trees considered healthy or in the process of dying. These results confirm the outbreak potential of P. semipunctata in its native Mediterranean-climate Eucalyptus forest under severe water stress, and indicate that continued drying will increase the likelihood of outbreaks.
      PubDate: 2015-10-30
      DOI: 10.3390/f6113868
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3882-3898: Aboveground Biomass Estimation Using
           Structure from Motion Approach with Aerial Photographs in a Seasonal
           Tropical Forest

    • Authors: Tetsuji Ota, Miyuki Ogawa, Katsuto Shimizu, Tsuyoshi Kajisa, Nobuya Mizoue, Shigejiro Yoshida, Gen Takao, Yasumasa Hirata, Naoyuki Furuya, Takio Sano, Heng Sokh, Vuthy Ma, Eriko Ito, Jumpei Toriyama, Yukako Monda, Hideki Saito, Yoshiyuki Kiyono, Sophal Chann, Nang Ket
      Pages: 3882 - 3898
      Abstract: We investigated the capabilities of a canopy height model (CHM) derived from aerial photographs using the Structure from Motion (SfM) approach to estimate aboveground biomass (AGB) in a tropical forest. Aerial photographs and airborne Light Detection and Ranging (LiDAR) data were simultaneously acquired under leaf-on canopy conditions. A 3D point cloud was generated from aerial photographs using the SfM approach and converted to a digital surface model (DSMP). We also created a DSM from airborne LiDAR data (DSML). From each of DSMP and DSML, we constructed digital terrain models (DTM), which are DTMP and DTML, respectively. We created four CHMs, which were calculated from (1) DSMP and DTMP (CHMPP); (2) DSMP and DTML (CHMPL); (3) DSML and DTMP (CHMLP); and (4) DSML and DTML (CHMLL). Then, we estimated AGB using these CHMs. The model using CHMLL yielded the highest accuracy in four CHMs (R2 = 0.94) and was comparable to the model using CHMPL (R2 = 0.93). The model using CHMPP yielded the lowest accuracy (R2 = 0.79). In conclusion, AGB can be estimated from CHM derived from aerial photographs using the SfM approach in the tropics. However, to accurately estimate AGB, we need a more accurate DTM than the DTM derived from aerial photographs using the SfM approach.
      PubDate: 2015-10-30
      DOI: 10.3390/f6113882
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3899-3922: Characterizing the Height Structure and
           Composition of a Boreal Forest Using an Individual Tree Crown Approach
           Applied to Photogrammetric Point Clouds

    • Pages: 3899 - 3922
      Abstract: Photogrammetric point clouds (PPC) obtained by stereomatching of aerial photographs now have a resolution sufficient to discern individual trees. We have produced such PPCs of a boreal forest and delineated individual tree crowns using a segmentation algorithm applied to the canopy height model derived from the PPC and a lidar terrain model. The crowns were characterized in terms of height and species (spruce, fir, and deciduous). Species classification used the 3D shape of the single crowns and their reflectance properties. The same was performed on a lidar dataset. Results show that the quality of PPC data generally approaches that of airborne lidar. For pixel-based canopy height models, viewing geometry in aerial images, forest structure (dense vs. open canopies), and composition (deciduous vs. conifers) influenced the quality of the 3D reconstruction of PPCs relative to lidar. Nevertheless, when individual tree height distributions were analyzed, PPC-based results were very similar to those extracted from lidar. The random forest classification (RF) of individual trees performed better in the lidar case when only 3D metrics were used (83% accuracy for lidar, 79% for PPC). However, when 3D and intensity or multispectral data were used together, the accuracy of PPCs (89%) surpassed that of lidar (86%).
      PubDate: 2015-10-30
      DOI: 10.3390/f6113899
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3923-3945: Detecting Stems in Dense and Homogeneous
           Forest Using Single-Scan TLS

    • Authors: Shaobo Xia, Cheng Wang, Feifei Pan, Xiaohuan Xi, Hongcheng Zeng, He Liu
      Pages: 3923 - 3945
      Abstract: Stem characteristics of plants are of great importance to both ecology study and forest management. Terrestrial laser scanning (TLS) may provide an effective way to characterize the fine-scale structures of vegetation. However, clumping plants, dense foliage and thin structure could intensify the shadowing effect and pose a series of problems in identifying stems, distinguishing neighboring stems, and merging disconnected stem parts in point clouds. This paper presents a new method to automatically detect stems in dense and homogeneous forest using single-scan TLS data. Stem points are first identified with a two-scale classification method. Then a clustering approach is used to group the candidate stem points. Finally, a direction-growing algorithm based on a simple stem curve model is applied to merge stem points. Field experiments were carried out in two different bamboo plots with a stem density of about 7500 stems/ha. Overall accuracy of the stem detection is 88% and the quality of detected stems is mainly affected by the shadowing effect. Results indicate that the proposed method is feasible and effective in detection of bamboo stems using TLS data, and can be applied to other species of single-stem plants in dense forests.
      PubDate: 2015-10-30
      DOI: 10.3390/f6113923
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3946-3969: Participatory Multi-Criteria Assessment
           of Forest Planning Policies in Conflicting Situations: The Case of

    • Authors: Montserrat Acosta, Serafin Corral
      Pages: 3946 - 3969
      Abstract: Sustainable forest planning should involve the participation of stakeholder communities in the decision-making process. This participation can help avoid the possible rejection of new planning measures. In this paper, the decision-making process to implement regulations on the use of forest tracks on the island of Tenerife (Canary Islands, Spain) is analyzed. In recent years, the number of people using the island’s forest environments has notably increased, leading to conflicts between different users of the tracks; as a result, the Island Council of Tenerife is working on regulating these pathways. This paper describes the framing analysis, design, and implementation of a participatory multi-criteria approach to explore, together with stakeholders, the best policy alternatives related to forest planning and management issues of forest track use. To do this, a set of tools has been developed, consisting of institutional analysis, participatory methods, and multi-criteria assessment techniques.
      PubDate: 2015-11-03
      DOI: 10.3390/f6113946
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3970-3984: Forest Biomass Energy Resources in
           China: Quantity and Distribution

    • Authors: Caixia Zhang, Leiming Zhang, Gaodi Xie
      Pages: 3970 - 3984
      Abstract: As one of the most important renewable and sustainable energy sources, the forest biomass energy resource has always been the focus of attention of scholars and policy makers. However, its potential is still uncertain in China, especially with respect to its spatial distribution. In this paper, the quantity and distribution of Chinese forest biomass energy resources are explored based mainly on forestry statistics data rather than forest resource inventory data used by most previous studies. The results show that the forest biomass energy resource in China was 169 million tons in 2010, of which wood felling and bucking residue (WFBR),wood processing residue (WPR), bamboo processing residue, fuel wood and firewood used by farmers accounted for 38%, 37%, 6%, 4% and 15%, respectively. The highest resource was located in East China, accounting for nearly 39.0% of the national amount, followed by the Southwest and South China regions, which accounted for 17.4% and 16.3%, respectively. At the provincial scale, Shandong has the highest distribution, accounting for 11.9% of total resources, followed by Guangxi and Fujian accounting for 10.3% and 10.2%, respectively. The actual wood-processing residue (AWPR) estimated from the actual production of different wood products (considering the wood transferred between regions) showed apparent differences from the local wood processing residue (LWPR), which assumes that no wood has been transferredbetween regions. Due to the large contribution of WPR to total forestry bioenergy resources, the estimation of AWPR will provide a more accurate evaluation of the total amount and the spatial distribution of forest biomass energy resources in China.
      PubDate: 2015-11-04
      DOI: 10.3390/f6113970
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3985-4000: Understanding the Factors Influencing
           Nonindustrial Private Forest Landowner Interest in Supplying Ecosystem
           Services in Cumberland Plateau, Tennessee

    • Authors: Nana Tian, Neelam Poudyal, Donald Hodges, Timothy Young, Kevin Hoyt
      Pages: 3985 - 4000
      Abstract: Private forests provide a range of ecosystem services for society including provisioning, regulating, cultural, and supporting services. Sustaining the supply of such services depends on the interest of nonindustrial private forest (NIPF) landowners in managing their forests for such services. Assessing factors that influence NIPF landowner intentions would be useful in identifying potential suppliers of ecosystem services and in designing and implementing outreach and education programs to elevate the interests of less interested landowners. Using data collected from a mail survey of NIPF landowners on the Cumberland Plateau of Tennessee, this study examined how landowner interest in supplying ecosystem services was influenced by socio-demographic characteristics, economic and market factors, land management objectives, and ownership motivations. To that end, a multivariate logistic regression model was employed to analyze the supply of three types of ecosystem services: carbon storage (regulating service), water quality (provisioning service), and aesthetics (cultural service). Results revealed that landowner interest in managing forests for ecosystem services were significantly related to socio-demographic factors, management and ownership characteristics, and availability of financial incentives. These findings will improve the understanding of the market segment of landowners as related to ecosystem services. The findings may facilitate the development of market protocols and outreach programs that promote payments for ecosystem services in Tennessee and elsewhere.
      PubDate: 2015-11-04
      DOI: 10.3390/f6113985
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4001-4033: Accounting for a Diverse Forest
           Ownership Structure in Projections of Forest Sustainability Indicators

    • Pages: 4001 - 4033
      Abstract: In this study, we assessed the effect of a diverse ownership structure with different management strategies within and between owner categories in long-term projections of economic, ecological and social forest sustainability indicators, representing important ecosystem services, for two contrasting Swedish municipalities. This was done by comparing two scenarios: one where the diversity of management strategies was accounted for (Diverse) and one where it was not (Simple). The Diverse scenario resulted in a 14% lower total harvested volume for the 100 year period compared to the Simple scenario, which resulted in a higher growing stock and a more favorable development of the ecological indicators. The higher proportion of sparse forests and the lower proportion of clear-felled sites made the Diverse scenario more appropriate for delivering access to common outdoor recreation activities, while the Simple scenario projected more job opportunities. Differences between the scenarios were considerable already in the medium term (after 20 years of simulation). Our results highlight the importance of accounting for the variety of management strategies employed by forest owners in medium- to long-term projections of the development of forest sustainability indicators.
      PubDate: 2015-11-06
      DOI: 10.3390/f6114001
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4034-4054: A Comparison of Airborne Laser Scanning
           and Image Point Cloud Derived Tree Size Class Distribution Models in
           Boreal Ontario

    • Authors: Margaret Penner, Murray Woods, Douglas Pitt
      Pages: 4034 - 4054
      Abstract: Airborne Laser Scanning (ALS) metrics have been used to develop area-based forest inventories; these metrics generally include estimates of stand-level, per hectare values and mean tree attributes. Tree-based ALS inventories contain desirable information on individual tree dimensions and how much they vary within a stand. Adding size class distribution information to area-based inventories helps to bridge the gap between area- and tree-based inventories. This study examines the potential of ALS and stereo-imagery point clouds to predict size class distributions in a boreal forest. With an accurate digital terrain model, both ALS and imagery point clouds can be used to estimate size class distributions with comparable accuracy. Nonparametric imputations were generally superior to parametric imputations; this may be related to the limitation of using a unimodal Weibull function on a relatively small prediction unit (e.g., 400 m2).
      PubDate: 2015-11-09
      DOI: 10.3390/f6114034
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4055-4058: Two-Year Survival of Gremmeniella
           abietina Conidia Collected on Branches Left on the Ground after Pine

    • Authors: Gaston Laflamme, Danny Rioux
      Pages: 4055 - 4058
      Abstract: In 1972, it was reported that viable ascospores and conidia of Gremmeniella abietina, North American race, were present on dead branches up to 10 months after they were killed. In Sweden, the survival period of conidia of G. abietina, European race, was reported to be over 18 months. We investigated the viability of conidia produced by G. abietina, European race, over a 2-year period in eastern Canada. Infected branches with pycnidia were left on the ground in June 2006. Branches were sampled every month during three growing seasons. Conidia germination was tested monthly and showed a very high rate of germination (76%–98%) from July 2006 to August 2007. Very few pycnidia were detected in the fall of 2007 and in May 2008. In June and July 2008, no pycnidia could be observed, the shoots being in an advanced stage of decomposition. In light of these observations, it is recommended to delay pine plantation until after two growing seasons following harvesting of diseased pine trees.
      PubDate: 2015-11-09
      DOI: 10.3390/f6114055
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4059-4071: Forest Parameter Prediction Using an
           Image-Based Point Cloud: A Comparison of Semi-ITC with ABA

    • Authors: Johannes Rahlf, Johannes Breidenbach, Svein Solberg, Rasmus Astrup
      Pages: 4059 - 4071
      Abstract: Image-based point clouds obtained using aerial photogrammetry share many characteristics with point clouds obtained by airborne laser scanning (ALS). Two approaches have been used to predict forest parameters from ALS: the area-based approach (ABA) and the individual tree crown (ITC) approach. In this article, we apply the semi-ITC approach, a variety of the ITC approach, on an image-based point cloud to predict forest parameters and compare the performance to the ABA. Norwegian National Forest Inventory sample plots on a site in southeastern Norway were used as the reference data. Tree crown objects were delineated using a watershed segmentation algorithm, and explanatory variables were calculated for each tree crown segment. A multivariate kNN model for timber volume, stem density, basal area and quadratic mean diameter with the semi-ITC approach produced RMSEs of 30%, 46%, 25%, 26%, respectively. The corresponding measures for the ABA were 30%, 51%, 26%, 35%, respectively. Univariate kNN models resulted in timber volume RMSEs of 25% for the semi-ITC approach and 22% for the ABA. A non-linear logistic regression model with the ABA produced an RMSE of 23%. Both approaches predicted timber volume with comparable precision and accuracy at the plot level. The multivariate kNN model was slightly more precise with the semi-ITC approach, while biases were larger
      PubDate: 2015-11-10
      DOI: 10.3390/f6114059
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4072-4087: Genetic Variability and Phylogeny of
           European mountain ash ringspot-associated virus RNA3 and RNA4

    • Pages: 4072 - 4087
      Abstract: The European mountain ash ringspot-associated virus (EMARaV) is a multipartite RNA virus of negative polarity. It infects Sorbus aucuparia (common name—rowan) trees throughout their whole distribution area in North and Central Europe. It causes mottling, chlorotic ringspots and decline of the whole plant. Infected rowans are serious virus sources for rowans and other potential hosts. EMARaV incidence and population structure was investigated in Germany, Finland, Sweden, Scotland, and Norway. Overall, EMARaV variants from 42 rowan trees distributed in 20 different locations were studied with regard to the genetic variability of the p3- and p4-coding genome region, as well as the 5′ and 3′ untranslated regions (UTR) of RNA3. In six of the 42 analyzed samples we found much higher sequence diversities than previously reported at the amino acid level in RNA3 encoded p3 protein sequences as well as at the nucleotide level on the 5′ and 3′ UTR. The other 36 EMARaV variants confirmed the assumed conservation of the nucleocapsid protein coding region. In contrast, the p4-coding genome region showed a high conservation of both nucleotide and amino acid sequences. Both EMARaV proteins were under strong purifying selection pressure, probably acting to maintain the functional integrity of the p3 and p4 proteins.
      PubDate: 2015-11-11
      DOI: 10.3390/f6114072
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4088-4104: Characterization of Fungal Pathogens
           Associated with White Pine Needle Damage (WPND) in Northeastern North

    • Authors: Kirk Broders, Isabel Munck, Stephen Wyka, Gloria Iriarte, Eric Beaudoin
      Pages: 4088 - 4104
      Abstract: Eastern white pine is a crucial ecological and economic component of forests in the northern USA and eastern Canada, and is now facing an emerging problem in white pine needle damage (WPND). It is still unclear whether WPND results from one, or the combination of several fungal pathogens. Therefore, the first objective of this study was to characterize the fungi associated with WPND in the northeastern United States and document the damage being done to mature eastern white pine as a result of repeated defoliation. To date, 22 species of fungi, either cultured from diseased pine needles or formed fruiting bodies on pine needles were identified based on morphology and sequence data. Lecanosticta acicola and a putative new species of Septorioides were the species most frequently recovered from diseased needles, in addition to needle cast fungi Lophophacidium dooksii and Bifusella linearis, two obligate fungal pathogens that were frequently observed on pine needles in the northeast, but have not been known to cause excessive defoliation of eastern white pine. A second objective was to monitor yearly the health of 63 pairs of healthy and unhealthy trees in eight affected locations throughout New England. Since 2012, affected trees are increasingly and repeatedly chlorotic and defoliated every year. Trees that were initially healthy are now exhibiting symptoms. While L. acicola appears to be the primary pathogen causing WPND, several other common needle pathogens are being more frequently observed and the role of climate change may be important in the disease ecology of WPND. These defoliation events, while once a sporadic occurrence, have now become more frequent as observed in continued crown deterioration of eastern white pine in long-term monitoring plots followed during the course of this three-year study.
      PubDate: 2015-11-12
      DOI: 10.3390/f6114088
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4105-4134: Monitoring Forest Recovery Following
           Wildfire and Harvest in Boreal Forests Using Satellite Imagery

    • Authors: Amar Madoui, Sylvie Gauthier, Alain Leduc, Yves Bergeron, Osvaldo Valeria
      Pages: 4105 - 4134
      Abstract: In the managed boreal forest, harvesting has become a disturbance as important as fire. To assess whether forest recovery following both types of disturbance is similar, we compared post-disturbance revegetation rates of forests in 22 fire events and 14 harvested agglomerations (harvested areas over 5–10 years in the same vicinity) in the western boreal forest of Quebec. Pre-disturbance conditions were first compared in terms of vegetation cover types and surficial deposit types using an ordination technique. Post-disturbance changes over 30 years in land cover types were characterized by vectors of succession in an ordination. Four post-disturbance stages were identified from the 48 land thematic classes in the Landsat images: “S0” stand initiation phase; “S1” early regeneration phase; “S2” stem exclusion phase; and “S3” the coniferous forest. Analyses suggest that fire occurs in both productive and unproductive forests, which is not the case for harvesting. Revegetation rates (i.e., rapidity with which forest cover is re-established) appeared to be more advanced in harvested agglomerations when compared with entire fire events. However, when considering only the productive forest fraction of each fire, the revegetation rates are comparable between the fire events and the harvested agglomerations. The S0 is practically absent from harvested agglomerations, which is not the case in the fire events. The difference in revegetation rates between the two disturbance types could therefore be attributed mostly to the fact that fire also occurs in unproductive forest, a factor that has to be taken into account in such comparisons.
      PubDate: 2015-11-18
      DOI: 10.3390/f6114105
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4135-4145: Designing Strategies for Epidemic
           Control in a Tree Nursery: the Case of Ash Dieback in the UK

    • Authors: Vasthi Chavez, Stephen Parnell, Frank Bosch
      Pages: 4135 - 4145
      Abstract: Ash dieback is a fungal disease (causal agent Hymenoscyphus fraxineus) infecting Common ash (Fraxinus excelsior) throughout temperate Europe. The disease was first discovered in the UK in 2012 in a nursery in Southern England, in plants which had been imported from the Netherlands. After sampling other recently planted sites across England, more infected trees were found. Tree trade from outside and across the UK may have facilitated the spread of invasive diseases which threaten the sustainability of forestry business, ecological niches and amenity landscapes. Detecting a disease in a nursery at an early stage and knowing how likely it is for the disease to have spread further in the plant trade network, can help control an epidemic. Here, we test two simple sampling rules that 1) inform monitoring strategies to detect a disease at an early stage, and 2) inform the decision of tracking forward the disease after its detection. We apply these expressions to the case of ash dieback in the UK and test them in different scenarios after disease introduction. Our results are useful to inform policy makers’ decisions on monitoring for the control and spread of tree diseases through the nursery trade.
      PubDate: 2015-11-18
      DOI: 10.3390/f6114135
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4146-4167: Towards Automated Characterization of
           Canopy Layering in Mixed Temperate Forests Using Airborne Laser Scanning

    • Authors: Reik Leiterer, Hossein Torabzadeh, Reinhard Furrer, Michael Schaepman, Felix Morsdorf
      Pages: 4146 - 4167
      Abstract: Canopy layers form essential structural components, affecting stand productivity and wildlife habitats. Airborne laser scanning (ALS) provides horizontal and vertical information on canopy structure simultaneously. Existing approaches to assess canopy layering often require prior information about stand characteristics or rely on pre-defined height thresholds. We developed a multi-scale method using ALS data with point densities >10 pts/m2 to determine the number and vertical extent of canopy layers (canopylayer, canopylength), seasonal variations in the topmost canopy layer (canopytype), as well as small-scale heterogeneities in the canopy (canopyheterogeneity). We first tested and developed the method on a small forest patch (800 ha) and afterwards tested transferability and robustness of the method on a larger patch (180,000 ha). We validated the approach using an extensive set of ground data, achieving overall accuracies >77% for canopytype and canopyheterogeneity, and >62% for canopylayer and canopylength. We conclude that our method provides a robust characterization of canopy layering supporting automated canopy structure monitoring.
      PubDate: 2015-11-18
      DOI: 10.3390/f6114146
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4168-4190: Quantifying the Effects of Biomass
           Market Conditions and Policy Incentives on Economically Feasible Sites to
           Establish Dedicated Energy Crops

    • Authors: Sandhya Nepal, Marco Contreras, George Stainback, John Lhotka
      Pages: 4168 - 4190
      Abstract: This study used a spatially-explicit model to identify the amount and spatial distribution of economically feasible sites for establishing dedicated energy crops under various market and policy scenarios. A sensitivity analysis was performed for a biomass market with different discount rates and biomass prices as well as policy scenarios including propriety tax exemption, carbon offset payments, and the inclusion of farmland for biomass production. The model was applied to a four-county study area in Kentucky representing conditions commonly found in the Ohio River Valley. Results showed that both biomass price and discount rate have a can strongly influence the amount of economically efficient sites. Rising the biomass price by 5 $·t−1 and lowering discount rate by 1% from the baseline scenario (40 $·t−1 and 5%) resulted in an over fourteen fold increment. Property tax exemption resulted in a fourfold increase, a carbon payment on only 1 $·t−1 caused a twelve fold increase and extending the landbase from marginal land to farmland only slightly increase the economically efficient sites. These results provide an objective evaluation of market and policy scenarios in terms of their potential to increase land availability for establishing dedicated energy crops and to promote the bioenergy industry.
      PubDate: 2015-11-18
      DOI: 10.3390/f6114168
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4191-4211: Phylogenetic Relationships among Species
           of Phellinus sensu stricto, Cause of White Trunk Rot of Hardwoods, from
           Northern North America

    • Authors: Nicholas Brazee
      Pages: 4191 - 4211
      Abstract: Species in Phellinus s.s. are some of the most important wood-decaying fungal pathogens in northern temperate forests, yet data on species incidence in North America remains limited. Therefore, phylogenetic analyses were performed using four loci (ITS, nLSU, tef1 and rpb2) with isolates representing 13 species. Results of phylogenetic analyses using maximum likelihood and Bayesian inference revealed that eight species of Phellinus s.s. occur in North America, and include: P. alni, P. arctostaphyli, P. betulinus, P. lundellii, P. nigricans, P. tremulae and two undescribed species, P. NA1 and P. NA2. Meanwhile, P. tuberculosus, P. igniarius s.s., P. populicola, P. laevigatus s.s. and P. orienticus were not detected and appear restricted to Europe and/or Asia. The tef1 dataset outperformed all other loci used and was able to discriminate among all 13 of the currently known Phellinus s.s. species with significant statistical support. The internal transcribed spacer (ITS) region performed well but a high level of intraspecific variation could lead to inflated taxa recognition. Phellinus alni exhibited the broadest host range, as demonstrated previously, and appears to be the most common species in northern hardwood (Acer-Betula-Fagus), northern floodplain (Fraxinus-Populus-Ulmus) and coastal alder (Alnus) forests of North America.
      PubDate: 2015-11-18
      DOI: 10.3390/f6114191
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4212-4227: Distributions and Losses of Logging
           Residues at Clear-Felled Areas during Extraction for Bioenergy: Comparing
           Dried- and Fresh-Stacked Method

    • Pages: 4212 - 4227
      Abstract: It is well known that a large proportion of available logging residues intended for extraction will not reach the energy-conversion industry, because some are lost during transportation or left on the clear-felled area. However, there is little understanding of where logging residue losses occur in the supply chain. In this study, the distribution of logging residues for two methods (dried- and fresh-stacked method) to extract logging residues were studied in one clear-felled area. In addition, residue fractions were examined in a detailed comparison. Even though the fresh-stacked method left somewhat more logging residues at the clear-felled area, the differences are small between the methods. Approximately 30% of the total amount of logging residues was left behind between the harvester heaps, with an additional 10%–15% under these heaps and approximately 2%–3% beneath the windrows. The final product that was delivered to the energy-conversion industry was very similar, regardless of the extraction method used. The delivered chipped logging residues had moisture contents of 37% and 36% following fresh- and dried-stacked methods respectively, and in both cases the needle content in the processed logging residues was approximately 10%. However, the total amount of fine fractions (needles and fines) was slightly higher following dried-stacking.
      PubDate: 2015-11-20
      DOI: 10.3390/f6114212
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4228-4244: Annual Cash Income from Community Forest
           Management in the Brazilian Amazon: Challenges for the Future

    • Authors: Marie-Gabrielle Piketty, Isabel Drigo, Philippe Sablayrolles, Evandro de Aquino, Driss Pena, Plinio Sist
      Pages: 4228 - 4244
      Abstract: Community forest management (CFM) is considered an alternative way to protect forests while providing income for smallholders. Since the mid-1990s, the number of CFM projects has rapidly increased in the Brazilian Amazon, although most of them still face several difficulties. In this paper, we discuss the obstacles to the financial viability of CFM in this region and propose some ways to overcome them. Based on evidence from five case studies, we assess the extent to which sustainable forest management for commercial timber production contributes to smallholder income. We show that harvesting timber only provides a limited cash income to smallholders, even though forest covers 80% of their landholding. Market access to timber is very uncertain and smallholder communities often fail to make a profit from their timber. Minimum remunerative public prices and support for timber marketing are thus needed. Simpler and more flexible procedures are required to reduce the high transaction costs of obtaining a permit and increase smallholder involvement in legal forest management for commercial purposes. Finally, a better assessment of timber potential in smallholder forest reserves through systematic inventories would be useful to avoid arousing false expectations.
      PubDate: 2015-11-20
      DOI: 10.3390/f6114228
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4245-4294: SimpleTree —An Efficient Open
           Source Tool to Build Tree Models from TLS Clouds

    • Authors: Jan Hackenberg, Heinrich Spiecker, Kim Calders, Mathias Disney, Pasi Raumonen
      Pages: 4245 - 4294
      Abstract: An open source tool named SimpleTree, capable of modelling highly accurate cylindrical tree models from terrestrial laser scan point clouds, is presented and evaluated. All important functionalities, accessible in the software via buttons and dialogues, are described including the explanation of all necessary input parameters. The method is validated utilizing 101 point clouds of six different tree species, in the main evergreen and coniferous trees. All scanned trees have been destructively harvested to get accurate estimates of above ground biomass with which we assess the accuracy of the SimpleTree-reconstructed cylinder models. The trees were grouped into four data sets and for each one a Concordance Correlation Coefficient of at least 0.92 (0.92, 0.97, 0.92, 0.94) and an total relative error at most  ~8 % (2.42%, 3.59%, –4.59%, 8.27%) was achieved in the comparison of the model results to the ground truth data. A global statistical improvement of derived cylinder radii is presented as well as an efficient optimization approach to automatically improve user given input parameters. An additional check of the SimpleTree results is presented via comparison to the results of trees reconstructed using an alternative, published method.
      PubDate: 2015-11-23
      DOI: 10.3390/f6114245
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4295-4327: Endurance and Adaptation of Community
           Forest Management in Quintana Roo, Mexico

    • Pages: 4295 - 4327
      Abstract: Despite regional deforestation threats, the state of Quintana Roo has maintained over 80% of its territory in forests. Community forest management (CFM) has played a pivotal role in forest cover and biodiversity conservation in the region. In this article, we present the institutional, socioeconomic and environmental conditions under which community-based forest management has been consolidated in the tropical state of Quintana Roo, which occupies the eastern half of Mexico’s Yucatan Peninsula. With a focus on management for timber and other market-based development strategies, we then examine the institutional and socioeconomic factors, as well as biophysical shocks, that have constrained community forestry development in the past 25 years, challenging its persistence. Following, we discuss how forest communities and institutions have responded and adapted to changing forest policies and markets as well as major environmental shocks from hurricanes and fires. CFM in Quintana Roo has shown resiliency since its institutionalization 30 years ago. Future challenges and opportunities include biodiversity conservation, carbon management through Reducing Emissions from Deforestation and Forest Degradation (REDD+) initiatives, market strengthening, business management training as well as the implementation of alternative silvicultural systems, particularly to manage sustainable populations of commercial timber species.
      PubDate: 2015-11-23
      DOI: 10.3390/f6114295
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4328-4348: Prescribing Innovation within a
           Large-Scale Restoration Programme in Degraded Subtropical Thicket in South

    • Authors: Anthony Mills, Marius Vyver, Iain Gordon, Anand Patwardhan, Christo Marais, James Blignaut, Ayanda Sigwela, Barney Kgope
      Pages: 4328 - 4348
      Abstract: Commonly cited requirements for bridging the “science‑practice divide” between practitioners and scientists include: political support, communication and experimentation. The Subtropical Thicket Restoration Programme was established in 2004 to catalyse investment in large-scale restoration of degraded subtropical thicket in the Eastern Cape, South Africa. Political support has been strong, with the South African government investing more than US$8 million into the programme. Communication occurred regularly among a wide range of stakeholders, and a restoration experiment—comprising 12 treatments and ~300 plots—was established over an area of ~75,000 km2. Despite this support, communication and experimentation, many pitfalls were encountered. For example, one restoration protocol became entrenched in the programme’s public as well as private sector operations without continual scrutiny of its efficacy. This was largely because results from the large-scale restoration experiment only emerged a decade after its conceptualization. As the programme enters its second decade there is recognition that a full range of “intelligent tinkering”—from small, rapid experiments to large, long-term experiments—needs to be planned and prescribed. The new working hypothesis is that prescribed innovation will reduce costs of restoration, increase survivorship of plants, increase income streams from restored landscapes, and promote new financing mechanisms for restoration.
      PubDate: 2015-11-24
      DOI: 10.3390/f6114328
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4349-4359: Effects of Land Use on Flow Rate Change

    • Pages: 4349 - 4359
      Abstract: The goal of this study was to analyze the impact of agriculture on the spatial and temporal variability of flow rate change indices from 1930 to 2008. The two indices used are the coefficient of immoderation (CI) and the coefficient of variation (CV). Values of these two indices are higher for the L’Assomption River agricultural watershed than for the Matawin River forested watershed due to higher runoff in the former than in the latter. The difference in these values between the two watersheds is greater for winter, but it is lower for summer, when the difference in runoff between the two watersheds is strongly attenuated by the presence of crops. Regarding the temporal variability, a difference between the two watersheds is observed in the fall. For the agricultural watershed, mean values of neither index show a break in slope, while a break is observed for the forested watershed. In both watersheds, both indices are positively correlated with maximum temperature and total rainfall in winter, but only to this latter climate variable in the fall. In springtime, the two indices are negatively correlated with minimum temperature in the forested watershed, but only CV is correlated, positively, with this same climate variable in the agricultural watershed.
      PubDate: 2015-11-24
      DOI: 10.3390/f6114349
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 4360-4373: Extent and Severity of Caliciopsis
           Canker in New England, USA: An Emerging Disease of Eastern White Pine
           (Pinus strobus L.)

    • Authors: Isabel Munck, William Livingston, Kyle Lombard, Thomas Luther, William Ostrofsky, Jennifer Weimer, Stephen Wyka, Kirk Broders
      Pages: 4360 - 4373
      Abstract: Caliciopsis canker is an emerging problem in Pinus growing regions of Eastern North America. The fungal disease caused by Caliciopsis pinea is associated with overstocked stands and poor sites, but few quantitative data are available. The objective of this study, therefore, was to assess the extent and severity of Caliciopsis canker and to explore environmental variables associated with disease to identify areas at risk of damage. During 2014, 58 sites across New England with >75% P. strobus basal area in public lands were surveyed. Most sites (72%) had Caliciopsis canker signs or symptoms. Caliciopsis pinea was successfully identified with molecular techniques. In sites with Caliciopsis canker, 36% of the mature pines were symptomatic. Pole sized and suppressed trees were more likely to be damaged than larger trees with dominant crown positions (p < 0.05). Pinus strobus density for sites with Caliciopsis canker was 311 trees/ha (mean P. strobus stand diameter = 40 cm) compared to 220 trees/ha (mean white pine stand diameter = 43 cm) for sites without Caliciopsis canker (p = 0.1). Caliciopsis canker symptoms tended to appear more frequently in stands with excessively drained, coarse textured soils derived from glacial outwash (86%) or stands with poorly drained soils and low fertility (78%) than in stands with well drained, more fertile soils (59%) (p = 0.1). The severity of symptoms varied among soil groups and was greater for excessively drained, nutrient poor soils than for well-drained, more fertile soils (p = 0.027).
      PubDate: 2015-11-24
      DOI: 10.3390/f6114360
      Issue No: Vol. 6, No. 11 (2015)
  • Forests, Vol. 6, Pages 3369-3394: Modeling Wood Fibre Length in Black
           Spruce (Picea mariana (Mill.) BSP) Based on Ecological Land Classification

    • Authors: Elisha Townshend, Bharat Pokharel, Art Groot, Doug Pitt, Jeffery Dech
      Pages: 3369 - 3394
      Abstract: Effective planning to optimize the forest value chain requires accurate and detailed information about the resource; however, estimates of the distribution of fibre properties on the landscape are largely unavailable prior to harvest. Our objective was to fit a model of the tree-level average fibre length related to ecosite classification and other forest inventory variables depicted at the landscape scale. A series of black spruce increment cores were collected at breast height from trees in nine different ecosite groups within the boreal forest of northeastern Ontario, and processed using standard techniques for maceration and fibre length measurement. Regression tree analysis and random forests were used to fit hierarchical classification models and find the most important predictor variables for the response variable area-weighted mean stem-level fibre length. Ecosite group was the best predictor in the regression tree. Longer mean fibre-length was associated with more productive ecosites that supported faster growth. The explanatory power of the model of fitted data was good; however, random forests simulations indicated poor generalizability. These results suggest the potential to develop localized models linking wood fibre length in black spruce to landscape-level attributes, and improve the sustainability of forest management by identifying ideal locations to harvest wood that has desirable fibre characteristics.
      PubDate: 2015-09-24
      DOI: 10.3390/f6103369
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3395-3411: Empirical Estimates of Aboveground
           Carbon in Open Eucalyptus Forests of South-Eastern Australia and Its
           Potential Implication for National Carbon Accounting

    • Authors: Liubov Volkova, Huiquan Bi, Simon Murphy, Christopher Weston
      Pages: 3395 - 3411
      Abstract: The aboveground carbon (AGC) storage of open Eucalyptus forests is unknown yet they are estimated to account for almost 25% of all Australian forests and about 60% of forests in Victoria. In this study we provide the best possible estimates of total AGC including tree biomass derived from destructive biomass sampling across 23 study plots established in open Eucalyptus forests in Victoria. The field estimates of AGC were then used for calibration of Australia’s National Carbon Accounting Model, FullCAM. The study aimed to develop a transparent and defendable method to estimate AGC for one of the most common Australian forests. Our calibrations showed that the 8.3 M ha of open Eucalyptus forests of SE Australia sequester at least 139 Mt C more than default FullCAM predictions. Because most of these forests are not subject to human-induced emission such as harvesting, only emissions and stock changes from a small area of these forests is reported in national inventories and international greenhouse emissions agreements. Concern for climate change and emission reduction will inevitably require land managers to come up with defendable methods of estimating forest carbon stocks and changes in all forest types; here we show how FullCAM can be further developed for this purpose.
      PubDate: 2015-09-24
      DOI: 10.3390/f6103395
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3412-3432: WIND-STORM: A Decision Support System
           for the Strategic Management of Windthrow Crises by the Forest Community

    • Pages: 3412 - 3432
      Abstract: Storms are one of the most damaging agents for European forests and can cause huge and long-term economic impacts on the forest sector. Recent events and research haves contributed to a better understanding and management of destructive storms, but public authorities still lack appropriate decision-support tools for evaluating their strategic decisions in the aftermath of a storm. This paper presents a decision support system (DSS) that compares changes in the dynamics of the regional forest-based sector after storm events under various crisis management options. First, the development and implementation of a regional forest model is addressed; then, the potential application of the model-based DSS WIND-STORM is illustrated. The results of simulated scenarios reveal that this DSS type is useful for designing a cost-effective regional strategy for storm-damage management in the context of scarce public resources and that public strategies must encompass the whole forest-based sector to be efficient. Additional benefits of such a DSS is to bring together decision-makers and forest stakeholders for a common objective and therefore to enhance participatory approaches to crisis management.
      PubDate: 2015-09-29
      DOI: 10.3390/f6103412
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3433-3451: An Uneven Playing Field: Regulatory
           Barriers to Communities Making a Living from the Timber from Their
           Forests–Examples from Cambodia, Nepal and Vietnam

    • Authors: David Gritten, Martin Greijmans, Sophie Lewis, Tol Sokchea, Julian Atkinson, Tan Quang, Bishnu Poudyal, Binod Chapagain, Lok Sapkota, Bernhard Mohns, Naya Paudel
      Pages: 3433 - 3451
      Abstract: Community forestry (CF) is widely viewed as the solution to many of the challenges facing forest management and governance in the Asia-Pacific region. However, it is often felt that CF is not delivering on its potential. This paper focuses on one possible limitation: the role of regulations in curbing communities’ ability to make a living from their timber resources. The work covers Cambodia, Nepal and Vietnam, using policy analyses, national level experts’ workshops, and focus group discussions in two CF sites in each country. The results highlight the fact that there are numerous, often prohibitive, regulations in place. One challenge is the regulations’ complexity, often requiring a level of capacity far beyond the ability of community members and local government staff. The paper puts forward various recommendations including simplifying regulations and making them more outcome-based, and facilitating key stakeholders, including government and community based organizations, working together on the design and piloting of forest monitoring based on mutually agreed forest management outcomes. The recommendations reflect the belief that for CF to succeed, communities must be allowed to make a meaningful living from their forests, a result of which would be increased investment in sustainable forest management.
      PubDate: 2015-09-29
      DOI: 10.3390/f6103433
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3452-3482: Legality Constraints: The Emergence of a
           Dual Market for Tropical Timber Products?

    • Authors: Mauro Masiero, Davide Pettenella, Paolo Cerutti
      Pages: 3452 - 3482
      Abstract: The European Union (EU), the United States of America (USA), and Australia have adopted specific measures to avoid the placing of illegal timber on their markets. These measures might encourage the diversion of timber products from traditional large importers to destinations with a less stringent regulatory framework. During 2001–2013, the international trade in tropical primary timber products (logs; sawnwood; veneers and plywood) decreased by 13% in volume and increased by almost 5% in value. Imports by Australia, the EU, and the USA halved, while those by emerging economies such as China and India initially remained stable and later increased. Tropical timber products—mostly logs and sawnwood—might have been diverted towards emerging economies over the period considered. This general trend is confirmed when analyzing imports from countries that are implementing voluntary partnership agreements (VPA) within the EU Forest Law Enforcement, Governance and Trade (FLEGT) Action Plan. Several factors might influence these market dynamics, including changes induced by the 2008 financial crisis and the increasing domestic demand for timber products by emerging nations. The effects of legality measures on market trends are still unclear. Nonetheless, they might have encouraged uncertainty with regards to traditional importers and favored emerging ones.
      PubDate: 2015-09-30
      DOI: 10.3390/f6103452
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3483-3500: Impact of a Mountain Pine Beetle
           Outbreak on Young Lodgepole Pine Stands in Central British Columbia

    • Authors: Amalesh Dhar, Nicole Balliet, Kyle Runzer, Christopher Hawkins
      Pages: 3483 - 3500
      Abstract: The current mountain pine beetle (MPB) (Dendroctonous ponderosae Hopkins) epidemic has severely affected pine forests of Western Canada and killed millions of hectares of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forest. Generally, MPB attack larger and older (diameter > 20 cm or >60 years of age) trees, but the current epidemic extends this limit with attacks on even younger and smaller trees. The study’s aim was to investigate the extent of MPB attack in young pine stands and its possible impact on stand dynamics. Although MPB attacks were observed in trees as small as 7.5 cm diameter at breast height (DBH) and as young as 13 years old, the degree of MPB attack (percent stems ha−1) increased with increasing tree diameter and age class (13–20, 21–40, 41–60, and 61–80 years old) (6.4%, 49.4%, 62.6%, and 69.5% attack, respectively, by age class) which is greater than that reported from previous epidemics for stands of this age. The mean density of surviving residual structure varied widely among age classes and ecological subzones. Depending on age class, 65% to 77% of the attacked stands could contribute to mid-term timber supply. The surviving residual structure of young stands offers an opportunity to mitigate the effects of MPB-attack on future timber supply, increase age class diversity, and enhance ecological resilience in younger stands.
      PubDate: 2015-09-30
      DOI: 10.3390/f6103483
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3501-3513: Native and Alien Plant Species Richness
           Response to Soil Nitrogen and Phosphorus in Temperate Floodplain and Swamp

    • Pages: 3501 - 3513
      Abstract: Soil nitrogen and phosphorus are commonly limiting elements affecting plant species richness in temperate zones. Our species richness-ecological study was performed in alder-dominated forests representing temperate floodplains (streamside alder forests of Alnion incanae alliance) and swamp forests (alder carrs of Alnion glutinosae alliance) in the Western Carpathians. Species richness (i.e., the number of vascular plants in a vegetation plot) was analyzed separately for native and alien vascular plants in 240 vegetation plots across the study area covering Slovakia, northern Hungary and southern Poland. The relationship between the species richness of each plant group and total soil nitrogen content, plant-available phosphorus and carbon to nitrogen (C/N) ratio was analyzed by generalized linear mixed models (GLMM) with Poisson error distribution and log-link function. The number of recorded native and alien species was 17–84 (average 45.4) and 0–9 (average 1.5) species per plot, respectively. The GLMMs were statistically significant (p ˂ 0.001) for both plant groups, but the total explained variation was higher for native (14%) than alien plants (9%). The richness of native species was negatively affected by the total soil nitrogen content and plant-available phosphorus, whereas the C/N ratio showed a positive impact. The alien richness was predicted only by the total soil nitrogen content showing a negative effect.
      PubDate: 2015-10-07
      DOI: 10.3390/f6103501
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3514-3527: Evaluating the Use of Tree Shelters for
           Direct Seeding of Castanea on a Surface Mine in Appalachia

    • Authors: Christopher Barton, Jarrod Miller, Kenton Sena, Patrick Angel, Michael French
      Pages: 3514 - 3527
      Abstract: American chestnut (Castanea dentata), once a primary constituent of the eastern hardwood forest ecosystem, was nearly extirpated from the forest canopy by the accidental introduction of chestnut blight (Cryphonectria parasitica). An intensive breeding program has sought to breed blight resistance from Chinese chestnut into American chestnuts, while maintaining as much of the desirable American chestnut phenotypes as possible. Previous studies suggest that these blight resistant American chestnuts, termed “restoration chestnuts”, are capable of thriving on reclaimed surface mines. We direct seeded pure Chinese, pure American, and three backcross lines into brown sandstone minesoil on a mine site in Pike County, KY. To investigate the effects of tree sheltering on survival and growth, we installed tree shelters on half the plots, and left the rest of the plots unsheltered. Results indicated that shelters were highly effective at reducing initial mortality. In addition, while pure Chinese chestnut survival was highest, the three backcross lines have also survived well on this site. Our study demonstrates that American, Chinese, and backcrossed chestnuts can survive through five growing seasons on reclaimed surface mines with the use of tree shelters.
      PubDate: 2015-10-07
      DOI: 10.3390/f6103514
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3528-3546: Carbon Budgets for Caribbean Mangrove
           Forests of Varying Structure and with Phosphorus Enrichment

    • Authors: Catherine Lovelock, Lorae Simpson, Lisa Duckett, Ilka Feller
      Pages: 3528 - 3546
      Abstract: There are few detailed carbon (C) budgets of mangrove forests, yet these are important for understanding C sequestration in mangrove forests, how they support the productivity of the coast and their vulnerability to environmental change. Here, we develop C budgets for mangroves on the islands of Twin Cays, Belize. We consider seaward fringing forests and interior scrub forests that have been fertilized with phosphorus (P), which severely limits growth of trees in the scrub forests. We found that respiration of the aboveground biomass accounted for 60%–80% of the fixed C and that respiration of the canopy and aboveground roots were important components of respiration. Soil respiration accounted for only 7%–11% of total gross primary production (GPP) while burial of C in soils was ~4% of GPP. Respiration by roots can account for the majority of soil respiration in fringing forests, while microbial processes may account 80% of respiration in scrub forests. Fertilization of scrub forests with P enhanced GPP but the proportion of C buried declined to ~2% of GPP. Net ecosystem production was 17%–27% of GPP similar to that reported for other mangrove forests. Carbon isotope signatures of adjacent seagrass suggest that dissolved C from mangroves is exported into the adjacent ecosystems. Our data indicate that C budgets can vary among mangrove forest types and with nutrient enrichment and that low productivity mangroves provide a disproportionate share of exported C.
      PubDate: 2015-10-07
      DOI: 10.3390/f6103528
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3547-3581: Loblolly Pine Growth Patterns on
           Reclaimed Mineland: Allometry, Biomass, and Volume

    • Authors: Jeremy Priest, Jeremy Stovall, Dean Coble, Brian Oswald, Hans Williams
      Pages: 3547 - 3581
      Abstract: Surface lignite coal mines in east Texas are commonly reforested using loblolly pine (Pinus taeda L.) following mining and reclamation activities. Due to the nature of such an extreme disturbance, altered growth patterns, growth rates, and productivity could be expected. We destructively sampled above- and belowground tissue to develop prediction equations specific to these sites. These prediction equations differed statistically from those found in the literature regarding unmined land. At the stand level, biomass and volume productivity appeared similar with young stands on reclaimed mineland performing slightly poorer than similarly managed unmined sites. Allometric partitioning of above- and belowground biomass differed statistically from the unmined allometric model previously studied. The allometric pattern on reclaimed mineland indicated greater partitioning of biomass belowground for young stands of low quadratic mean diameter relative to unmined stands. Older stands on reclaimed mineland exhibited no allometric partitioning differences from unmined stands, indicating the normal allometric pattern is resumed for stands greater than 10 years of age.
      PubDate: 2015-10-10
      DOI: 10.3390/f6103547
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3582-3593: Increased Biomass of Nursery-Grown
           Douglas-Fir Seedlings upon Inoculation with Diazotrophic Endophytic

    • Authors: Zareen Khan, Shyam Kandel, Daniela Ramos, Gregory Ettl, Soo-Hyung Kim, Sharon Doty
      Pages: 3582 - 3593
      Abstract: Douglas-fir (Pseudotsuga menziesii) seedlings are periodically challenged by biotic and abiotic stresses. The ability of endophytes to colonize the interior of plants could confer benefits to host plants that may play an important role in plant adaptation to environmental changes. In this greenhouse study, nursery-grown Douglas-fir seedlings were inoculated with diazotrophic endophytes previously isolated from poplar and willow trees and grown for fifteen months in nutrient-poor conditions. Inoculated seedlings had significant increases in biomass (48%), root length (13%) and shoot height (16%) compared to the control seedlings. Characterization of these endophytes for symbiotic traits in addition to nitrogen fixation revealed that they can also solubilize phosphate and produce siderophores. Colonization was observed through fluorescent microscopy in seedlings inoculated with gfp- and mkate-tagged strains. Inoculation with beneficial endophytes could prove to be valuable for increasing the production of planting stocks in forest nurseries.
      PubDate: 2015-10-12
      DOI: 10.3390/f6103582
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3594-3613: Estimating Values of Carbon
           Sequestration and Nutrient Recycling in Forests: An Application to the
           Stockholm-Mälar Region in Sweden

    • Authors: Ing-Marie Gren
      Pages: 3594 - 3613
      Abstract: We calculate values of forest carbon sequestration and nutrient recycling applying the replacement cost method. The value is then determined as the savings in costs by the replacement of more expensive abatement measures with these ecosystem services in cost-effective climate and nutrient programs. To this end, a dynamic optimization model is constructed, which accounts for uncertainty in sequestration. It is applied to the Stockholm-Mälar region in southeast Sweden where the EU 2050 climate policy for carbon emissions and the Baltic Sea action plan for nutrient discharges are applied. The results show that the value of carbon and nutrient sequestration can correspond to approximately 0.5% of the region’s gross domestic product, or 40% of the value of productive forest. The largest part of this value is attributed to carbon sequestration because of the relative stringency in targets and expensive alternative abatement measures. However, sequestration is uncertain because of stochastic weather conditions, and when society has a large risk aversion for not attaining climate and nutrient targets, the values of the forest carbon and nutrient sequestration can approach zero.
      PubDate: 2015-10-13
      DOI: 10.3390/f6103594
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3614-3664: Multiple-Use Zoning Model for Private
           Forest Owners in Agricultural Landscapes: A Case Study

    • Authors: Benoit Truax, Daniel Gagnon, France Lambert, Julien Fortier
      Pages: 3614 - 3664
      Abstract: Many small-scale private forest owners increasingly focus their management on amenity functions rather than on wood production functions. This paradigm shift is an opportunity to implement novel forestry management approaches, such as forested land zoning. Forest zoning consists in separating the land base in three zones that have different management objectives: (1) conservation zones; (2) ecosystem management zones; and (3) intensive production zones, which locally increase productivity, as a trade off to increase the land area dedicated to conservation and ecosystem management. We evaluate the ecological feasibility of implementing forest zoning on a private property (216 ha) at St-Benoît-du-Lac, Québec (Canada) characterised by agricultural and forest land uses. As a basis for delineating conservation and ecosystem management zones, historical and contemporary data and facts on forest composition and dynamics were reviewed, followed by a detailed forest vegetation analysis of forest communities. Delineating intensive production zones was straightforward, as fertile agricultural field margins located downslope were used to establish multifunctional hybrid poplar buffers. At St-Benoît-du-Lac, a realistic zoning scenario would consist of (1) conservation zones covering 25% of the forestland (37 ha); (2) ecosystem management zones covering 75% of the forestland (113 ha, including restoration zones on 24 ha); and (3) intensive production zones on 2.8 ha. Based on a yield projection of 13 t/ha/year for hybrid poplars, only 5.6% of agricultural field areas would need to be converted into agroforestry systems to allow for the loss of wood production in a conservation zone of 37 ha of forest. Ecosystem services provision following the implementation of zoning would include increased habitat quality, biodiversity protection and enhancement (by restoration of some tree species), carbon storage, non-point source aquatic pollution control, local biomass production for heating, and increased forest economic value.
      PubDate: 2015-10-14
      DOI: 10.3390/f6103614
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3665-3682: Biomass Stock and Carbon Sequestration
           in a Chronosequence of Pinus massoniana Plantations in the Upper Reaches
           of the Yangtze River

    • Authors: Meta Justine, Wanqin Yang, Fuzhong Wu, Bo Tan, Muhammad Khan, Yeyi Zhao
      Pages: 3665 - 3682
      Abstract: Planted forest plays a significant role in carbon sequestration and climate change mitigation; however, little information has been available on the distribution patterns of carbon pools with stand ages in Pinus massoniana Plantations. We investigated the biomass stock and carbon sequestration across a chronosequence (3-, 5-, 7-, 9-, 12-, 15-, 19-, 29-, 35- and 42-year) of stands with the main objectives: (1) to determine the biomass and carbon stock of the forest ecosystem; and (2) to identify factors influencing their distribution across the age series. Simple random sampling was used for collecting field data in the ten (10) stand ages. Three 20 × 20 m standard plots were laid out in February 2015 across the chronosequence. The diameter at breast height (DBH) and tree height (H) of each tree within each plot were measured using calipers and height indicator. Sub-plots of 2 × 2 m were established in each main plot for collecting soil samples at a 0–30- and 30–60-cm depth. Plantation biomass increased with increasing stand ages, ranging from 0.84 tonnes per hectare (t·ha−1) in the three-year stand to 252.35 t·ha−1 in the 42-year stand. The aboveground biomass (AGB) contributed 86.51%; the maximum value is 300-times the minimum value. Carbon concentrations and storage in mineral soil decreased with increasing soil depth, but were controlled by the management history of the ecosystem. The total ecosystem carbon storage varies with stand ages, ranging from 169.90 t·ha−1 in the five-year plantation to 326.46 t·ha−1 in the 42-year plantation, of which 80.29% comes from the mineral soil carbon and 19.71% from the vegetation. The ratio of the total carbon sequestration by the 42-year to the three-year stand was 1.70, implying substantial amounts of carbon accumulation during the transition period from young to mature-aged trees. The forest ecosystem had the capacity of storing up to 263.16 t·ha−1 carbon, assisting in mitigating climate change by sequestrating 965.83 t·ha−1 of CO2 equivalents, indicating that the forest is an important carbon sink.
      PubDate: 2015-10-15
      DOI: 10.3390/f6103665
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3683-3685: Michelotti, L. A. and Miesel J. R.
           Source Material and Concentration of Wildfire-Produced Pyrogenic Carbon
           Influence Post-Fire Soil Nutrient Dynamics. Forests 2015, 6,

    • Authors: Lucas Michelotti, Jessica Miesel
      Pages: 3683 - 3685
      Abstract: The authors wish to make the following corrections to this paper [1]: [...]
      PubDate: 2015-10-15
      DOI: 10.3390/f6103683
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3686-3703: Influence of Rhizobia Inoculation on
           Biomass Gain and Tissue Nitrogen Content of Leucaena leucocephala
           Seedlings under Drought

    • Authors: Gabriela Pereyra, Henrik Hartmann, Beate Michalzik, Waldemar Ziegler, Susan Trumbore
      Pages: 3686 - 3703
      Abstract: Anticipated increases in the frequency of heat waves and drought spells may have negative effects on the ability of leguminous trees to fix nitrogen (N). In seedlings of Leucaena leucocephala inoculated with Mesorhizobium loti or Rhizobium tropici, we investigated how the developmental stage and a short drought influenced overall biomass and the accumulation of carbon and N in plant tissues. In early developmental stages, the number of nodules and nodule biomass were correlated with total plant biomass and δ15N, and nodules and roots contributed 33%–35% of the seedling total N. Seedlings associated with R. tropici fixed more N and exhibited higher overall biomass compared with M. loti seedlings. Four and a half months after inoculation (140 days after inoculation, DAI), a short (15-day) drought inhibited seedling growth and caused a decline in total plant N, with the smallest decline in R. tropici seedlings. After 15 days of drought, i.e., 155 DAI, the nodules had accumulated proline, but the total amino acid concentration did not change. Our results indicate that N-fixation is independent of seedlings growth. In addition, R. tropici is a better choice than M. loti as a symbiont for Leucaena seedlings for forest restoration and agroforestry applications under increasingly drier conditions.
      PubDate: 2015-10-15
      DOI: 10.3390/f6103686
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3704-3732: Comparing ALS and Image-Based Point
           Cloud Metrics and Modelled Forest Inventory Attributes in a Complex
           Coastal Forest Environment

    • Authors: Joanne White, Christoph Stepper, Piotr Tompalski, Nicholas Coops, Michael Wulder
      Pages: 3704 - 3732
      Abstract: Digital aerial photogrammetry (DAP) is emerging as an alternate data source to airborne laser scanning (ALS) data for three-dimensional characterization of forest structure. In this study we compare point cloud metrics and plot-level model estimates derived from ALS data and an image-based point cloud generated using semi-global matching (SGM) for a complex, coastal forest in western Canada. Plot-level estimates of Lorey’s mean height (H), basal area (G), and gross volume (V) were modelled using an area-based approach. Metrics and model outcomes were evaluated across a series of strata defined by slope and canopy cover, as well as by image acquisition date. We found statistically significant differences between ALS and SGM metrics for all strata for five of the eight metrics we used for model development. We also found that the similarity between metrics from the two data sources generally increased with increasing canopy cover, particularly for upper canopy metrics, whereas trends across slope classes were less consistent. Model outcomes from ALS and SGM were comparable. We found the greatest difference in model outcomes was for H (ΔRMSE% = 5.04%). By comparison, ΔRMSE% was 2.33% for G and 3.63% for V. We did not discern any corresponding trends in model outcomes across slope and canopy cover strata, or associated with different image acquisition dates.
      PubDate: 2015-10-15
      DOI: 10.3390/f6103704
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3733-3747: Trade-Offs between Drought Survival and
           Rooting Strategy of Two South American Mediterranean Tree Species:
           Implications for Dryland Forests Restoration

    • Authors: Juan Ovalle, Eduardo Arellano, Rosanna Ginocchio
      Pages: 3733 - 3747
      Abstract: Differences in water-acquisition strategies of tree root systems can determine the capacity to survive under severe drought. We evaluate the effects of field water shortage on early survival, growth and root morphological variables of two South American Mediterranean tree species with different rooting strategies during two growing seasons. One year-old Quillaja saponaria (deep-rooted) and Cryptocarya alba (shallow-rooted) seedlings were established under two watering treatments (2 L·week−1·plant−1 and no water) in a complete randomized design. Watering improved the final survival of both species, but the increase was only significantly higher for the shallow-rooted species. The survival rates of deep- and shallow-rooted species was 100% and 71% with watering treatment, and 96% and 10% for the unwatered treatment, respectively. Root morphological variables of deep-rooted species such as surface area, volume, and diameter were higher under unwatered treatment. On the other hand, shallow-rooted species had a higher total root dry mass, length, surface area with watering treatments. Our findings suggest that deep-rooted species are highly recommended for reforestation in dry conditions, even under low soil water availability. Water supplements during the summer season can attenuate the differences between deep- and shallow-rooted species in their ability to survive drought during the early stage.
      PubDate: 2015-10-15
      DOI: 10.3390/f6103733
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3748-3762: Using Plant Temperature to Evaluate the
           Response of Stomatal Conductance to Soil Moisture Deficit

    • Authors: Ming-Han Yu, Guo-Dong Ding, Guang-Lei Gao, Yuan-Yuan Zhao, Lei Yan, Ke Sai
      Pages: 3748 - 3762
      Abstract: Plant temperature is an indicator of stomatal conductance, which reflects soil moisture stresses. We explored the relationship between plant temperature and soil moisture to optimize irrigation schedules in a water-stress experiment using Firmiana platanifolia (L. f.) Marsili in an incubator. Canopy temperature, leaf temperature, and stomatal conductance were measured using thermal imaging and a porometer. The results indicated that (1) stomatal conductance decreased with declines in soil moisture, and reflected average canopy temperature; (2) the variation of the leaf temperature distribution was a reliable indicator of soil moisture stress, and the temperature distribution in severely water-stressed leaves exhibited greater spatial variation than that in the presence of sufficient irrigation; (3) thermal indices (Ig) and crop water stress index (CWSI) were theoretically proportional to stomatal conductance (gs), Ig was certified to have linearity relationship with gs and CWSI have a logarithmic relationship with gs, and both of the two indices can be used to estimate soil moisture; and (4) thermal imaging data can reflect water status irrespective of long-term water scarcity or lack of sudden rainfall. This study applied thermal imaging methods to monitor plants and develop adaptable irrigation scheduling, which are important for the formulation of effective and economical agriculture and forestry policy.
      PubDate: 2015-10-16
      DOI: 10.3390/f6103748
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3763-3778: Maturation in Corymbia torelliana ×
           C. citriodora Stock Plants: Effects of Pruning Height on Shoot Production,
           Adventitious Rooting Capacity, Stem Anatomy, and Auxin and Abscisic Acid

    • Authors: Ivar Wendling, Paul Warburton, Stephen Trueman
      Pages: 3763 - 3778
      Abstract: Repeated pruning of stock plants is a common approach to delaying maturation and maintaining the propagation ability of cuttings, but little is known about the hormonal or anatomical basis for this phenomenon. We tested the effect of two different stock-plant pruning heights (15 cm and 30 cm) on shoot production, rooting capacity and rooted cutting vigour of six clones of the eucalypt Corymbia torelliana × C. citriodora. We determined whether differences in rooting potential were related to indole-3-acetic (IAA) and abscisic acid (ABA) concentrations, or the degree of lignification or sclerification, of the cuttings. Maintaining stock plants at 15 cm height sometimes reduced the production of stem cuttings. However, it often increased the ensuing percentage of cuttings that formed roots, with mean rooting across all clones increasing from 30%–53%. Therefore, the number of rooted cuttings produced by short stock plants was similar to, or higher than, the number produced by tall stock plants. Cuttings from shorter stock plants had faster root elongation and occasionally greater root dry mass, shoot dry mass or shoot height than cuttings from tall stock plants. These differences in rooting potential were generally not related to differences in IAA or ABA concentrations of the cuttings or to differences in their stem anatomy. Pruning at the lower height was more effective in maintaining clonal juvenility, supporting previous findings that stock plant maturation is a limiting factor in clonal propagation of Corymbia torelliana × C. citriodora.
      PubDate: 2015-10-16
      DOI: 10.3390/f6103763
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3779-3798: Effects of Visual Grading on Northern
           Red Oak (Quercus rubra L.) Seedlings Planted in Two Shelterwood Stands on
           the Cumberland Plateau of Tennessee, USA

    • Authors: Stacy Clark, Scott Schlarbaum, Callie Schweitzer
      Pages: 3779 - 3798
      Abstract: Artificial regeneration of oak has been generally unsuccessful in maintaining the oak component in productive upland forests of eastern North America. We tested visual grading effects on quality-grown northern red oak (Quercus rubra) seedlings planted in two submesic stands on the Cumberland Plateau escarpment of Tennessee, USA. Seedlings were grown for one year using advanced fertilization and irrigation protocols to increase overall size of seedlings, but large variability in size was still evident. Seedlings were divided into two grades prior to planting. The “standard” grade represented seedlings that had undergone a light culling, and the “premium” grade represented the highest quality seedlings. Seven years after planting in a midstory-removal stand, 50 percent of trees survived, growth was negligible, and seedling grade had no effect on survival and yearly growth. In a shelterwood harvest stand, premium grade seedlings had taller height and larger basal diameter (BD) (241 cm and 29.5 mm, respectively) compared to standard seedlings (201 cm and 25.9 mm, respectively), and a two-year height growth advantage was achieved by planting premium grade compared to standard grade seedlings. Competitive ability and planting shock were similar between grades, and we postulate that an exceptional drought and large size variability in both grades equalized response. While our findings should be confirmed through additional testing, they suggest currently accepted seedling quality standards for northern red oak should be refined to improve regeneration efforts on productive sites in the eastern United States.
      PubDate: 2015-10-21
      DOI: 10.3390/f6103779
      Issue No: Vol. 6, No. 10 (2015)
  • Forests, Vol. 6, Pages 3799-3808: Assessing 62 Chinese Fir (Cunninghamia
           lanceolata) Breeding Parents in a 12-Year Grafted Clone Test

    • Authors: Huiquan Zheng, Dehuo Hu, Runhui Wang, Ruping Wei, Shu Yan
      Pages: 3799 - 3808
      Abstract: Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is one of the major commercial conifer species in China. The present study concentrated on the assessment of growth, wood property traits, and strobili number in a 12-year grafted clone test of 62 Chinese fir breeding parents, aiming to describe the variation and correlations between these traits and to identify parent clones with the highest potential for future breeding. The results indicate that all of the growth (height, diameter at breast height, stem volume, crown-width) and wood property (wood basic density and hygroscopicity) traits varied significantly (p < 0.01) among clones, with coefficients of variation ranging from 7.6% to 30.6%. Furthermore, these traits consistently had a moderate to high (0.39–0.87) repeatability estimate (broad-sense heritability). Remarkable clonal differences were also observed for the production of male and female strobili. Phenotypic correlations among growth traits were strong (p < 0.01) and positive. Significantly negative correlations (p < 0.01 or 0.05) were found between wood basic density and growth (except for height) and hygroscopicity. The production of male and female strobili appeared to be significantly (p < 0.01) positively correlated with each other. A notable number of faster-growing parent clones were identified (n = 30); 11 of these had higher density wood with an average realized gain of 10.5% in diameter, and a 5.4% gain in wood basic density. When selection was made for growth and strobili, 10 faster-growing parent clones with medium to high production of female strobili were identified.
      PubDate: 2015-10-22
      DOI: 10.3390/f6103799
      Issue No: Vol. 6, No. 10 (2015)
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