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  Subjects -> FORESTS AND FORESTRY (Total: 95 journals)
Acta Silvatica et Lignaria Hungarica     Open Access  
Advance in Forestry Research     Open Access   (Followers: 2)
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: 3)
Agrociencia     Open Access   (Followers: 2)
Agroforestry Systems     Hybrid Journal   (Followers: 13)
Annals of Forest Science     Hybrid Journal   (Followers: 3)
Appita Journal: Journal of the Technical Association of the Australian and New Zealand Pulp and Paper Industry     Full-text available via subscription   (Followers: 4)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 6)
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: 74)
Canadian Journal of Plant Science     Full-text available via subscription   (Followers: 11)
Ciência Florestal     Open Access   (Followers: 2)
Ciencia forestal en México     Open Access   (Followers: 1)
Colombia Forestal     Open Access  
Dissertationes Forestales     Open Access  
European Journal of Forest Research     Hybrid Journal   (Followers: 3)
Expert Opinion on Environmental Biology     Partially Free  
Floresta e Ambiente     Open Access   (Followers: 1)
Forest Ecology and Management     Hybrid Journal   (Followers: 29)
Forest Pathology     Hybrid Journal   (Followers: 1)
Forest Phytophthoras     Open Access   (Followers: 1)
Forest Policy and Economics     Hybrid Journal   (Followers: 16)
Forest Research Papers     Open Access   (Followers: 2)
Forest Science     Full-text available via subscription   (Followers: 5)
Forest Science and Practice     Hybrid Journal   (Followers: 4)
Forest Science and Technology     Partially Free   (Followers: 1)
Forest Systems     Open Access  
Foresta Veracruzana     Open Access   (Followers: 2)
Forestry Chronicle     Full-text available via subscription   (Followers: 8)
Forestry Studies : Metsanduslikud Uurimused     Open Access   (Followers: 2)
Forestry: An International Journal of Forest Research     Hybrid Journal   (Followers: 10)
Forests     Open Access   (Followers: 3)
Forests, Trees and Livelihoods     Partially Free   (Followers: 3)
Ghana Journal of Forestry     Full-text available via subscription  
Holzforschung     Full-text available via subscription  
iForest : Biogeosciences and Forestry     Open Access   (Followers: 2)
INNOTEC : Revista del Laboratorio Tecnológico del Uruguay     Open Access  
International Forestry Review     Full-text available via subscription   (Followers: 6)
International Journal of Forest Engineering     Hybrid Journal  
International Journal of Forest, Soil and Erosion     Open Access   (Followers: 3)
International Journal of Forestry Research     Open Access   (Followers: 5)
ISRN Forestry     Open Access   (Followers: 1)
Journal of Agriculture, Forestry and the Social Sciences     Full-text available via subscription   (Followers: 1)
Journal of Biodiversity Management & Forestry     Full-text available via subscription  
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: 3)
Journal of Forestry     Full-text available via subscription   (Followers: 6)
Journal of Forestry Research     Hybrid Journal   (Followers: 5)
Journal of Horticulture and Forestry     Open Access   (Followers: 1)
Journal of Natural Resources Policy Research     Hybrid Journal   (Followers: 12)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Sustainable Forestry     Hybrid Journal   (Followers: 6)
Journal of Tropical Forestry and Environment     Open Access  
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: 1)
La Calera     Open Access  
Landscapes     Hybrid Journal   (Followers: 17)
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: 7)
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: 7)
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 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: 3)
Science, Technology and Arts Research Journal     Open Access  
Small-scale Forestry     Hybrid Journal   (Followers: 2)
Southern African Forestry Journal     Full-text available via subscription   (Followers: 2)
Southern Forests: a Journal of Forest Science     Hybrid Journal   (Followers: 4)
Tanzania Journal of Forestry and Nature Conservation     Full-text available via subscription  
Trees     Hybrid Journal   (Followers: 5)
Urban Forestry & Urban Greening     Hybrid Journal   (Followers: 7)
Veld & Flora     Full-text available via subscription   (Followers: 2)
Wood and Fiber Science     Full-text available via subscription   (Followers: 3)
Forests
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  This is an Open Access Journal Open Access journal
     ISSN (Print) 1999-4907
     Published by MDPI Homepage  [124 journals]   [SJR: 0.439]   [H-I: 5]
  • Forests, Vol. 5, Pages 1122-1142: Sensitivity Analysis of 3D Individual
           Tree Detection from LiDAR Point Clouds of Temperate Forests

    • Authors: Wei Yao, Jan Krull, Peter Krzystek, Marco Heurich
      Pages: 1122 - 1142
      Abstract: Light detection and ranging (LiDAR) sampling or full-area coverage is deemed as favorable means to achieve timely and robust characterizations of forests. Recently, a 3D segmentation approach was developed for extracting single trees from LiDAR data. However, key parameters for modules used in the strategy had to be empirically determined. This paper highlights a comprehensive study for the sensitivity analysis of 3D single tree detection from airborne LiDAR data. By varying key parameters, their influences on results are to be quantified. The aim of the study is to enlighten the optimal combination of parameter values towards new applications. For the experiment, a number of sample plots from two temperate forest sites in Europe were selected. LiDAR data with a point density of 25 pts/m2 over the first site in the Bavarian forest national park were captured with under both leaf-on and leaf-off conditions. Moreover, a Riegl scanner was used to acquire data over the Austrian Alps forest with four-fold point densities of 5 pts/m2, 10 pts/m2, 15 pts/m2 and 20 pts/m2, respectively, under leaf-off conditions. The study results proved the robustness and efficiency of the 3D segmentation approach. Point densities larger than 10 pts/m2 did not seem to significantly contribute to the improvement in the performance of 3D tree detection. The performance of the approach can be further examined and improved by optimizing the parameter settings with respect to different data properties and forest structures.
      PubDate: 2014-05-28
      DOI: 10.3390/f5061122
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1143-1162: Governing Forest Landscape Restoration:
           Cases from Indonesia

    • Authors: Cora van Oosten, Petrus Gunarso, Irene Koesoetjahjo, Freerk Wiersum
      Pages: 1143 - 1162
      Abstract: Forest landscape restoration includes both the planning and implementation of measures to restore degraded forests within the perspective of the wider landscape. Governing forest landscape restoration requires fundamental considerations about the conceptualisation of forested landscapes and the types of restoration measures to be taken, and about who should be engaged in the governance process. A variety of governance approaches to forest landscape restoration exist, differing in both the nature of the object to be governed and the mode of governance. This paper analyses the nature and governance of restoration in three cases of forest landscape restoration in Indonesia. In each of these cases, both the original aim for restoration and the initiators of the process differ. The cases also differ in how deeply embedded they are in formal spatial planning mechanisms at the various political scales. Nonetheless, the cases show similar trends. All cases show a dynamic process of mobilising the landscape’s stakeholders, plus a flexible process of crafting institutional space for conflict management, negotiation and decision making at the landscape level. As a result, the landscape focus changed over time from reserved forests to forested mosaic lands. The cases illustrate that the governance of forest landscape restoration should not be based on strict design criteria, but rather on a flexible governance approach that stimulates the creation of novel public-private institutional arrangements at the landscape level.
      PubDate: 2014-05-28
      DOI: 10.3390/f5061143
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1163-1184: Wood Density-Climate Relationships Are
           Mediated by Dominance Class in Black Spruce (Picea mariana (Mill.) B.S.P.)
           

    • Authors: Wei Xiang, David Auty, Tony Franceschini, Mathew Leitch, Alexis Achim
      Pages: 1163 - 1184
      Abstract: The relationships between climate and wood density components, i.e., minimum ring density, maximum ring density and mean ring density have been studied mainly in dominant trees. However, the applicability of the findings to trees of other dominance classes is unclear. The aim of this study was to address whether climate differentially influences wood density components among dominance classes. X-ray densitometry data was obtained from 72 black spruce (Picea mariana (Mill.) B.S.P.) trees harvested in Northwestern Ontario, Canada. Dominant, co-dominant and intermediate trees were sampled and the data analysed using mixed-effect modelling techniques. For each density component, models were first fitted to the pooled data using ring width and cambial age as predictors, before monthly climatic variables were integrated into the models. Then, separate models were fitted to the data from each dominance class. In general, the addition of climatic factors led to a small but significant improvement in model performance. The predicted historical trends were well synchronized with the observed data. Our results indicate that trees from all dominance classes in a stand should be sampled in order to fully characterize wood density-climate relationships.
      PubDate: 2014-05-28
      DOI: 10.3390/f5061163
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1185-1193: Discovery of Walnut Twig Beetle,
           Pityophthorus juglandis, Associated with Forested Black Walnut, Juglans
           nigra, in the Eastern U.S.

    • Authors: Gregory Wiggins, Jerome Grant, Paris Lambdin, Paul Merten, Katheryne Nix, Denita Hadziabdic, Mark Windham
      Pages: 1185 - 1193
      Abstract: Thousand cankers disease (TCD) is an insect-mediated disease of walnut trees (Juglans spp.) involving walnut twig beetle (Pityophthorus juglandis) and a fungal pathogen (Geosmithia morbida). Although first documented on walnut species in the western U.S., TCD is now found on black walnut (J. nigra) in five states in the eastern U.S. Most collections of P. juglandis or G. morbida are from trees in agriculturally- or residentially-developed landscapes. In 2013, 16 pheromone-baited funnel traps were deployed in or near black walnuts in forested conditions to assess the risk of infestation of forested trees by P. juglandis. Four of the 16 funnel traps collected adult P. juglandis from three forested areas (one in North Carolina and two in Tennessee). These collections, while in forested settings, may still be strongly influenced by human activities. The greatest number of P. juglandis (n = 338) was collected from a forested location in an urbanized area near a known TCD-positive tree. The other two forested locations where P. juglandis (n = 3) was collected were in areas where camping is common, and infested firewood may have introduced P. juglandis unintentionally into the area. Future studies to assess P. juglandis on more isolated forested walnuts are planned.
      PubDate: 2014-05-28
      DOI: 10.3390/f5061185
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1194-1211: Growth Response of Northern White-Cedar
           (Thuja occidentalis) to Natural Disturbances and Partial Cuts in Mixedwood
           Stands of Quebec, Canada

    • Authors: Jean-Claude Ruel, Jean-Martin Lussier, Sabrina Morissette, Nicolas Ricodeau
      Pages: 1194 - 1211
      Abstract: Northern white-cedar (Thuja occidentalis) is a species of high commercial and ecological value, the abundance of which has been declining since the middle of the 19th century. Very little information regarding its silviculture in mixedwood stands is currently available, even though a significant portion of wood resources comes from these stands. The present study is a retrospective analysis of white-cedar growth in partially harvested mixedwood stands of western Quebec, Canada. Eight stands distributed across two regions were analyzed. Dendrochronological approaches examined long-term diameter growth for sample white-cedar trees and stems of associated species. These approaches were used to reconstruct stand characteristics at the time of harvesting, together with local harvesting intensity. The study demonstrated white-cedar’s capacity to maintain good growth for long periods of time and at large tree sizes. Accession to the upper canopy positions occurs through repeated episodes of suppression/release, most of which seem to be associated with spruce budworm (Choristoneura fumiferana) outbreaks. White-cedar response to partial harvesting varies with tree size, residual basal area and species composition. Growth response was generally stronger for small trees, even though large trees still maintained the best diameter growth. Growth of white-cedar was negatively affected by an increase in softwood proportion in basal area. Growth responses to harvesting could be sustained for a period of 20 years.
      PubDate: 2014-05-28
      DOI: 10.3390/f5061194
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1212-1223: Estimating Soil Displacement from Timber
           Extraction Trails in Steep Terrain: Application of an Unmanned Aircraft
           for 3D Modelling

    • Authors: Marek Pierzchała, Bruce Talbot, Rasmus Astrup
      Pages: 1212 - 1223
      Abstract: Skid trails constructed for timber extraction in steep terrain constitute a serious environmental concern if not well planned, executed and ameliorated. Carrying out post-harvest surveys in monitoring constructed trails in such terrain is an onerous task for forest administrators, as hundreds of meters need to be surveyed per site, and the quantification of parameters and volumes is largely based on assumptions of trail symmetry and terrain uniformity. In this study, aerial imagery captured from a multi-rotor Unmanned Aerial Vehicle was used in generating a detailed post-harvest terrain model which included all skid trails. This was then compared with an Airborne Laser Scanning derived pre-harvest terrain model and the dimensions, slopes and cut-and-fill volumes associated with the skid trails were determined. The overall skid trail length was 954 m, or 381 m·ha−1 with segments varying from 40–60 m, inclinations from 3.9% to 9.6%, and cut volumes, from 1.7 to 3.7 m3 per running meter. The methods used in this work can be used in rapidly assessing the extent of disturbance and erosion risk on a wide range of sites. The multi-rotor Unmanned Aerial Vehicle (UAV) was found to be highly suited to the task, given the relatively small size of harvested stands, their shape and their location in the mountainous terrain.
      PubDate: 2014-06-10
      DOI: 10.3390/f5061212
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1224-1242: Vulnerability of Plantation Carbon
           Stocks to Defoliation under Current and Future Climates

    • Authors: Elizabeth Pinkard, Keryn Paul, Michael Battaglia, Jody Bruce
      Pages: 1224 - 1242
      Abstract: Plantation species globally are susceptible to a range of defoliating pests, but pest damage is rarely considered when estimating biomass C sequestered by these forests. We examined the impacts of defoliation on Eucalyptus globulus plantation C stocks under current and future climates using Mycospharella Leaf Disease (MLD) as a case study, hypothesising that biomass C sequestered in plantations would decrease with a warming and drying climate, and that impacts of defoliation would be strongly site dependent. Six E. globulus plantation sites with varying productivity were selected for the study. Current (1961–2005) and future (2030 and 2070) severity and frequency of MLD were estimated for each site using the bioclimatic niche model CLIMEX, and used as inputs to the process-based forest productivity model CABALA. CABALA was used to develop annual estimates of total living and dead biomass for current, 2030 and 2070 climate scenarios. Averaged annual biomass outputs were used to initialise the carbon accounting model FullCAM for calculation of C sequestered in living and dead biomass over a growing cycle. E. globulus plantations were predicted to sequester between 4.8 and 13.4 Mg C·ha−1·year−1 over 10 years under current climatic conditions. While our estimates suggest that overall this is likely to increase slightly under future climates (up to a maximum of 17.2 Mg C·ha−1·year−1 in 2030, and a shift in minimum and maximum values to 7.6 and 17.6 respectively in 2070), we predict considerable between-site variation. Our results suggest that biomass C sequestration will not necessarily be enhanced by future climatic conditions in all locations. We predict that biomass C sequestration may be reduced considerably by defoliation meaning that any gains in C sequestration associated with changing climate may be substantially offset by defoliation. While defoliation has a generally small impact under current climatic conditions in these plantations, the impact is likely to increase in the future, with reductions of up to 40% predicted for some sites under future climates. We conclude that the combined impacts of climate change on pest frequency and severity, and on host responses to defoliation, may reduce biomass C sequestration in E. globulus plantations in the future.
      PubDate: 2014-06-10
      DOI: 10.3390/f5061224
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1243-1266: Comparative Structural Dynamics of the
           Janj Mixed Old-Growth Mountain Forest in Bosnia and Herzegovina: Are
           Conifers in a Long-Term Decline'

    • Authors: Srdjan Keren, Renzo Motta, Zoran Govedar, Radovan Lucic, Milan Medarevic, Jurij Diaci
      Pages: 1243 - 1266
      Abstract: Regression of conifers in European mixed old-growth mountain forests has been observed for a long period and studied from different aspects. Old-growth (OG) forests in Bosnia and Herzegovina (BiH) have not experienced heavy air pollution and chronic overbrowsing that have affected many other European OG forests, while climatic and anthropogenic disturbances have been well documented. We analysed stand structure in the Janj OG forest, compared it with inventories of Lom and Perucica OG forests (BiH) and with earlier inventories of the same reserves. At present, OG forest Janj is characterized by a high growing stock (1215 m3∙ha−1). This is due to good site quality, prevalence of conifers (84%) and dominant endogenous processes in recent decades. In all three OG forests, indicators of structural change exhibited progression of European beech over time. Historical evidence revealed the occurrence of warm summers and droughts followed by bark beetle outbreaks in the 1920s, 1940s and early 1950s, which in turn influenced a marked conifer decline. It seems likely that repeated canopy opening released waves of European beech regeneration. These stand structural changes have delayed the rejuvenation of conifers and can help explain the early observations of conifer decline.
      PubDate: 2014-06-10
      DOI: 10.3390/f5061243
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1267-1283: Mapping Forest Biomass Using Remote
           Sensing and National Forest Inventory in China

    • Authors: Ling Du, Tao Zhou, Zhenhua Zou, Xiang Zhao, Kaicheng Huang, Hao Wu
      Pages: 1267 - 1283
      Abstract: Quantifying the spatial pattern of large-scale forest biomass can provide a general picture of the carbon stocks within a region and is of great scientific and political importance. The combination of the advantages of remote sensing data and field survey data can reduce uncertainty as well as demonstrate the spatial distribution of forest biomass. In this study, the seventh national forest inventory statistics (for the period 2004–2008) and the spatially explicit MODIS Land Cover Type product (MCD12C1) were used together to quantitatively estimate the spatially-explicit distribution of forest biomass in China (with a resolution of 0.05°, ~5600 m). Our study demonstrated that the calibrated forest cover proportion maps allow proportionate downscaling of regional forest biomass statistics to forest cover pixels to produce a relatively fine-resolution biomass map. The total stock of forest biomass in China was 11.9 Pg with an average of 76.3 Mg ha−1 during the study period; the high values were located in mountain ranges in northeast, southwest and southeast China and were strongly correlated with forest age and forest density.
      PubDate: 2014-06-11
      DOI: 10.3390/f5061267
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1284-1303: Forest Cover Database Updates Using
           Multi-Seasonal RapidEye Data—Storm Event Assessment in the Bavarian
           Forest National Park

    • Authors: Alata Elatawneh, Adelheid Wallner, Ioannis Manakos, Thomas Schneider, Thomas Knoke
      Pages: 1284 - 1303
      Abstract: This study is a part of a research program that investigates the potential of RapidEye (RE) satellite data for timely updates of forest cover databases to reflect both regular management activities and sudden changes due to bark beetle and storms. Applied here in the Bavarian Forest National Park (BFNP) in southeastern Germany, this approach detected even small changes between two data takes, thus, facilitating documentation of regular management activities. In the case of a sudden event, forest cover databases also serve as a baseline for damage assessment. A storm event, which occurred on 13 July, 2011, provided the opportunity to assess the effectiveness of multi-seasonal RE data for rapid damage assessment. Images of sufficient quality (<20% cloud cover) acquired one day before the storm event were used as a baseline. Persistent cloud cover meant that the first “after event” image of sufficient quality was acquired six weeks later, on 22 August, 2011. Aerial images (AI) for the official damage assessment done by the BFNP administration were acquired on that same day. The RE analysis for damage assessment was completed two weeks after the post-event data take with an overall accuracy of 96% and a kappa coefficient of 0.86. In contrast, the official aerial image survey from the BFNP was first released in late November, eleven weeks later. Comparison of the results from the two analyses showed a difference in the detected amount of forest cover loss of only 3%. The estimated cost of the RE approach was four times less than that of the standard digital AI procedure employed by the BFNP.
      PubDate: 2014-06-11
      DOI: 10.3390/f5061284
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1304-1330: Evaluation and Comparison of QuickBird
           and ADS40-SH52 Multispectral Imagery for Mapping Iberian Wild Pear Trees
           (Pyrus bourgaeana, Decne) in a Mediterranean Mixed Forest

    • Authors: Salvador Arenas-Castro, Juan Fernández-Haeger, Diego Jordano-Barbudo
      Pages: 1304 - 1330
      Abstract: The availability of images with very high spatial and spectral resolution from airborne sensors or those aboard satellites is opening new possibilities for the analysis of fine-scale vegetation, such as the identification and classification of individual tree species. To evaluate the potential of these images, a study was carried out to compare the spatial, spectral and temporal resolution between QuickBird and ADS40-SH52 imagery, in order to discriminate and identify, within the mixed Mediterranean forest, individuals of the Iberian wild pear (Pyrus bourgaeana). This is a typical species of the Mediterranean forest, but its biology and ecology are still poorly known. The images were subjected to different correction processes and data were homogenized. Vegetation classes and individual trees were identified on the images, which were classified from two types of supervised classification (Maximum Likelihood and Support Vector Machines) on a pixel-by-pixel basis. The classification values were satisfactory. The classifiers were compared, and Support Vector Machines was the algorithm that provided the best results in terms of overall accuracy. The QuickBird image showed higher overall accuracy (86.16%) when the Support Vector Machines algorithm was applied. In addition, individuals of Iberian wild pear were discriminated with probability of over 55%, when the Maximum Likelihood algorithm was applied. From the perspective of improving the sampling effort, these results are a starting point for facilitating research on the abundance, distribution and spatial structure of P. bourgaeana at different scales, in order to quantify the conservation status of this species.
      PubDate: 2014-06-11
      DOI: 10.3390/f5061304
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1331-1340: Performance of Oak Seedlings Grown under
           Different Oust® XP Regimes

    • Authors: Andrew Self, Andrew Ezell, Dennis Rowe
      Pages: 1331 - 1340
      Abstract: Herbaceous weed control (HWC) is prescribed for growing season control of vegetative competition in hardwood afforestation attempts on former agricultural areas. Without HWC, planted seedlings often exhibit poor growth and survival. While currently employed HWC methods are proven, there is a substantial void in research comparing HWC treatments spanning multiple years. A total of 4,320 bare-root seedlings of three oak species were planted on three Mississippi sites. All sites were of comparable soils and received above average precipitation for the majority of the three-year study. Eight combinations of HWC and mechanical site preparation were utilized at each site, with 480 seedlings planted in each of the nine blocks, and a total of 1,440 seedlings per species planted across all sites. Treatments were installed on 3.1 m centers, with mechanical treatments as follows: control, subsoiling, bedding, and combination plowing. HWC treatments included one and two-year applications of Oust® XP. Treatments were applied over seedlings post-planting in 1.5 m bands, at a rate of 140.1 g product/hectare. Excepting one species, HWC dependent height or groundline diameter differences were not detected among mechanical treatments, species, HWC regime, or combinations thereof. No survival differences were observed among site preparation treatments or species. However, analysis detected a growing season/HWC treatment interaction for seedling survival.
      PubDate: 2014-06-11
      DOI: 10.3390/f5061331
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1341-1355: Innovation Insights from North American
           Forest Sector Research: A Literature Review

    • Authors: Eric Hansen, Erlend Nybakk, Rajat Panwar
      Pages: 1341 - 1355
      Abstract: The promise of increased industry competitiveness through innovation has driven interest in innovation by industry managers, policy makers and academicians. Forest sector researchers have produced a strong body of work in recent years. This article provides a review of work originating in North America during the period 2000–2013. The review includes 28 journal articles focused on the forest sector in the U.S. and Canada. Seven important themes from the literature are identified and discussed: defining innovation and innovativeness; measuring innovativeness; factors influencing innovativeness; new product development; climate/culture; innovation systems; and innovativeness and firm performance. The positive culture and climate within a company has a clear connection to improved innovativeness and firm performance. Generally, findings describing the culture of the forest sector show a conservative group that fails to sufficiently invest in innovativeness and innovation. Culture change presents a significant opportunity within the industry to strive toward the improved development of new products, processes and business systems to reap the rewards of improved performance. The implications for managers and researchers are outlined.
      PubDate: 2014-06-12
      DOI: 10.3390/f5061341
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1356-1373: Mapping Above- and Below-Ground Biomass
           Components in Subtropical Forests Using Small-Footprint LiDAR

    • Authors: Lin Cao, Nicholas Coops, John Innes, Jinsong Dai, Guanghui She
      Pages: 1356 - 1373
      Abstract: In order to better assess the spatial variability in subtropical forest biomass, the goal of our study was to use small-footprint, discrete-return Light Detection and Ranging (LiDAR) data to accurately estimate and map above- and below-ground biomass components of subtropical forests. Foliage, branch, trunk, root, above-ground and total biomass of 53 plots (30 × 30 m) were modeled using a range of LiDAR-derived metrics, with individual models built for each of the three dominant forest types using stepwise multi-regression analysis. A regular grid covered the entire study site with cell size 30 × 30 m corresponding to the same size of the plots; it was generated for mapping each biomass component. Overall, results indicate that biomass estimation was more accurate in coniferous forests, compared with the mixed and broadleaved plots. The coefficient of determination (R2) for individual models was significantly enhanced compared with an overall generic, or common, model. Using independent stand-level data from ground inventory, our results indicated that overall the model fit was significant for most of the biomass components, with relationships close to a 1:1 line, thereby indicating no significant bias. This research illustrates the potential for LiDAR as a technology to assess subtropical forest carbon accurately and to provide a better understanding of how forest ecosystems function in this region.
      PubDate: 2014-06-16
      DOI: 10.3390/f5061356
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1374-1390: LiDAR Remote Sensing of Forest Structure
           and GPS Telemetry Data Provide Insights on Winter Habitat Selection of
           European Roe Deer

    • Authors: Michael Ewald, Claudia Dupke, Marco Heurich, Jörg Müller, Björn Reineking
      Pages: 1374 - 1390
      Abstract: The combination of GPS-Telemetry and resource selection functions is widely used to analyze animal habitat selection. Rapid large-scale assessment of vegetation structure allows bridging the requirements of habitat selection studies on grain size and extent, particularly in forest habitats. For roe deer, the cold period in winter forces individuals to optimize their trade off in searching for food and shelter. We analyzed the winter habitat selection of roe deer (Capreolus capreolus) in a montane forest landscape combining estimates of vegetation cover in three different height strata, derived from high resolution airborne Laser-scanning (LiDAR, Light detection and ranging), and activity data from GPS telemetry. Specifically, we tested the influence of temperature, snow height, and wind speed on site selection, differentiating between active and resting animals using mixed-effects conditional logistic regression models in a case-control design. Site selection was best explained by temperature deviations from hourly means, snow height, and activity status of the animals. Roe deer tended to use forests of high canopy cover more frequently with decreasing temperature, and when snow height exceeded 0.6 m. Active animals preferred lower canopy cover, but higher understory cover. Our approach demonstrates the potential of LiDAR measures for studying fine scale habitat selection in complex three-dimensional habitats, such as forests.
      PubDate: 2014-06-16
      DOI: 10.3390/f5061374
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 1391-1408: Soil Organic Carbon in Particle Size and
           Density Fractionations under Four Forest Vegetation-Land Use Types in
           Subtropical China

    • Authors: Suyun Shang, Peikun Jiang, Scott Chang, Zhaoliang Song, Juan Liu, Lei Sun
      Pages: 1391 - 1408
      Abstract: Data on the effect of vegetation and land use type on soil organic carbon (SOC) distribution in particle-size and density fractions in the subtropical forest region in China will improve our understanding of the C sequestration potential of those different vegetation-land use types. We quantified SOC in particle size (coarse, medium and fine) and density fractions (light and heavy) under four types of common forest vegetation-land uses: an evergreen broad-leaf forest, a pine forest, a managed chestnut forest and an intensively managed bamboo forest in subtropical China. The SOC in the 0–20 and 20–40 cm soil layers was the highest in the bamboo forest (31.6–34.8 g·C·kg−1), followed by the evergreen broad-leaf forest (10.2–19.9 g·C·kg−1), the pine forest (8.5–13.6 g·C·kg−1) and the chestnut forest (6.3–12.2 g·C·kg−1). The SOC was largely in the coarse fraction under the evergreen broad-leaf, pine and bamboo forests, while it was largely in the fine fraction in the chestnut forest, suggesting that SOC in the chestnut forest was likely more stable than that in the other forest vegetation-land use types. The SOC in the light fraction under the four forest vegetation-land use types ranged from 1.4 to 13.1 g·C·kg−1 soil, representing 21%–37% of the total organic C; this suggests that the majority of the SOC was in the better protected, heavy fraction. We conclude that forest vegetation-land use type (and the associated management practices) influenced SOC distribution in particle size and density fractions in the studied subtropical forests in southeastern China.
      PubDate: 2014-06-17
      DOI: 10.3390/f5061391
      Issue No: Vol. 5, No. 6 (2014)
       
  • Forests, Vol. 5, Pages 862-884: The Value of Forest Conservation for Water
           Quality Protection

    • Authors: Melissa Kreye, Damian Adams, Francisco Escobedo
      Pages: 862 - 884
      Abstract: Forests protect water quality by reducing soil erosion, sedimentation, and pollution; yet there is little information about the economic value of conserving forests for water quality protection in much of the United States. To assess this value, we conducted a meta-analysis of willingness-to-pay (WTP) for protecting unimpaired waters, and econometrically determined several significant drivers of WTP: type of conservation instrument (tool), aquatic resource type, geographic context, spatial scale, time, and household income. Using a benefit transfer to two highly forested sites, we illustrate the importance of these factors on WTP for water quality protection programs, forest conservation and policy design.
      PubDate: 2014-05-07
      DOI: 10.3390/f5050862
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 885-900: Heavy Metal Contamination in Soils of
           Remnant Natural and Plantation Forests in an Urbanized Region of the Pearl
           River Delta, China

    • Authors: Enqing Hou, Huimin Xiang, Jianli Li, Jiong Li, Dazhi Wen
      Pages: 885 - 900
      Abstract: Remnant forests in urban areas provide vital ecosystem services but are susceptible to many human activities including heavy metal emissions. In this study, we collected 192 samples of mineral soils at depths of 0–3, 3–13 and 13–23 cm in 16 remnant forests (eight natural forests and eight plantation forests) in the urbanized Pearl River Delta, China. We assessed the potential risks of soil Cu, Zn, Pb, Mn, Ni and Cr to the vegetation in these forests based on their total and 0.1 M HCl extractable concentrations. The mean concentrations for all soil samples were 202.7, 102.0, 75.7, 24.3, 30.3, and 7.8 mg/kg for Zn, Mn, Pb, Cu, Cr, and Ni, respectively. Compared to background values, total soil Zn concentrations were higher for both the natural and plantation forests located near both industrial and non-industrial sites; total soil Cu and Pb concentrations were higher near industrial sites, particularly for the natural forests. Total soil Pb, Cu, and Mn concentrations and exchangeable soil Pb and Mn concentrations were higher in the natural forests than in the plantation forests. Total soil Cu and Pb concentrations and extractable soil Cu, Pb, Zn, and Mn concentrations decreased with soil depth. Based on these results and previous findings of continued acidification and low phosphorus availability of these soils, we recommend that the growth of these remnant forests can be improved by the application of phosphate rock.
      PubDate: 2014-05-13
      DOI: 10.3390/f5050885
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 901-918: Scientific Basis for Sustainable
           Management of Eucalyptus and Populus as Short-Rotation Woody Crops in the
           U.S.

    • Authors: Eric Vance, Craig Loehle, T. Wigley, Philip Weatherford
      Pages: 901 - 918
      Abstract: Short rotation woody crops (SRWC), fast growing tree species that are harvested on short, repeated intervals, can augment traditional fiber sources. These crops have economic and environmental benefits stemming from their capability of supplying fiber on a reduced land base in close proximity to users and when sensitive sites cannot be accessed. Eucalyptus and Populus appear to be genera with the greatest potential to provide supplemental fiber in the U.S. Optimal productivity can be achieved through practices that overcome site limitations and by choosing the most appropriate sites, species, and clones. Some Eucalyptus species are potentially invasive, yet field studies across multiple continents suggest they are slower to disperse than predicted by risk assessments. Some studies have found lower plant and animal diversity in SRWC systems compared to mature, native forests, but greater than some alterative land uses and strongly influenced by stand management, land use history, and landscape context. Eucalyptus established in place of grasslands, arable lands, and, in some cases, native forests can reduce streamflow and lower water tables due to higher interception and transpiration rates but results vary widely, are scale dependent, and are most evident in drier regions.
      PubDate: 2014-05-14
      DOI: 10.3390/f5050901
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 919-935: The Application of Stem Analysis Methods
           to Estimate Carbon Sequestration in Arboreal Shrubs from a Single
           Measurement of Field Plots

    • Authors: Peter Beets, Mark Kimberley, Graeme Oliver, Stephen Pearce
      Pages: 919 - 935
      Abstract: Repeated measurements of plots are usually made to directly determine carbon stock changes over time. However, it is sometimes only practical or feasible to inventory plots at the end of a period of interest, and stock changes need to be predicted retrospectively from supplementary information on growth rate. This situation applied to the natural stratum of post-1989 forest in New Zealand, for which carbon sequestration over Commitment Period 1 (2008–2012) of the Kyoto Protocol needed to be estimated from inventory data acquired in 2012. A pilot study was undertaken to test and refine methods that could be applied in the national inventory, utilizing plots that had been installed in eligible post-1989 natural forest in 2008. The plots had actual measurements and shrub biomass sampling to directly estimate carbon stocks in 2008. These plots were re-measured and sampled in 2012, and basal disc samples from plants growing adjacent to each plot collected to provide data to model stem annual increment in diameter and height of shrubs growing on the plot. We present the results of this test of methods, and discuss refinements to field procedures and calculation methods to be applied in the national inventory of this stratum of post-1989 forest in 2012.
      PubDate: 2014-05-16
      DOI: 10.3390/f5050919
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 936-951: Analysis of the Influence of Plot Size and
           LiDAR Density on Forest Structure Attribute Estimates

    • Authors: Luis Ruiz, Txomin Hermosilla, Francisco Mauro, Miguel Godino
      Pages: 936 - 951
      Abstract: This paper assesses the combined effect of field plot size and LiDAR density on the estimation of four forest structure attributes: volume, total biomass, basal area and canopy cover. A total of 21 different plot sizes were considered, obtained by decreasing the field measured plot radius value from 25 to 5 m with regular intervals of 1 m. LiDAR data densities were simulated by randomly removing LiDAR pulses until reaching nine different density values. In order to avoid influence of the digital terrain model spatial resolution, eight different resolutions were considered (from 0.25 to 2 m grid size) and tested. A set of per-plot LiDAR metrics was extracted for each parameter combination. Prediction models of forest attributes were defined using forward stepwise ordinary least-square regressions. Results show that the highest R2 values are reached by combining large plot sizes and high LiDAR data density values. However, plot size has a greater effect than LiDAR point density. In general, minimum plot areas of 500–600 m2 are needed for volume, biomass and basal area estimates, and of 300–400 m2 for canopy cover. Larger plot sizes do not significantly increase the accuracy of the models, but they increase the cost of fieldwork.
      PubDate: 2014-05-16
      DOI: 10.3390/f5050936
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 952-977: Contribution of Small-Scale Gum and Resin
           Commercialization to Local Livelihood and Rural Economic Development in
           the Drylands of Eastern Africa

    • Authors: Asmamaw Abtew, Jürgen Pretzsch, Laura Secco, Tarig Mohamod
      Pages: 952 - 977
      Abstract: This paper examines the extent to which the economic gains derived from gum and resin commercialization impact rural livelihood improvement under different resource management regimes in the drylands of Ethiopia and Sudan. Primary data were collected through semi-structured interviews with 240 randomly selected small-scale producers in four regions with gradients of resource management regimes. The survey was supplemented by secondary data, group discussions and key informant interviews. In the four regions, gum and resin income contributes to 14%–23% of the small-scale producers’ household income. Absolute income was positively correlated with resource management regime and commercialization level. It was higher from cultivated resources on private lands, followed by regulated access to wild resources. In open-access resources, the producers’ income was the lowest, although accessed by the poor and women. However, dependence on gum and resin was higher in open-access resource areas. Households’ socioeconomic characteristics, resource access, production and marketing variables determining income from gum and resin were identified and their variation across the cases is discussed. Overall, gum and resin commercialization in the study areas play a potential poverty alleviation role as a source of regular income, a safety net, and a means of helping producers move out of poverty.
      PubDate: 2014-05-16
      DOI: 10.3390/f5050952
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 978-991: Redefining Secondary Forests in the
           Mexican Forest Code: Implications for Management, Restoration, and
           Conservation

    • Authors: Francisco Román-Dañobeytia, Samuel Levy-Tacher, Pedro Macario-Mendoza, José Zúñiga-Morales
      Pages: 978 - 991
      Abstract: The Mexican Forest Code establishes structural reference values to differentiate between secondary and old-growth forests and requires a management plan when secondary forests become old-growth and potentially harvestable forests. The implications of this regulation for forest management, restoration, and conservation were assessed in the context of the Calakmul Biosphere Reserve, which is located in the Yucatan Peninsula. The basal area and stem density thresholds currently used by the legislation to differentiate old-growth from secondary forests are 4 m2/ha and 15 trees/ha (trees with a diameter at breast height of >25 cm); however, our research indicates that these values should be increased to 20 m2/ha and 100 trees/ha, respectively. Given that a management plan is required when secondary forests become old-growth forests, many landowners avoid forest-stand development by engaging slash-and-burn agriculture or cattle grazing. We present evidence that deforestation and land degradation may prevent the natural regeneration of late-successional tree species of high ecological and economic importance. Moreover, we discuss the results of this study in the light of an ongoing debate in the Yucatan Peninsula between policy makers, non-governmental organizations (NGOs), landowners and researchers, regarding the modification of this regulation to redefine the concept of acahual (secondary forest) and to facilitate forest management and restoration with valuable timber tree species.
      PubDate: 2014-05-21
      DOI: 10.3390/f5050978
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 992-1010: Low-Density LiDAR and Optical Imagery for
           Biomass Estimation over Boreal Forest in Sweden

    • Authors: Iurii Shendryk, Margareta Hellström, Leif Klemedtsson, Natascha Kljun
      Pages: 992 - 1010
      Abstract: Knowledge of the forest biomass and its change in time is crucial to understanding the carbon cycle and its interactions with climate change. LiDAR (Light Detection and Ranging) technology, in this respect, has proven to be a valuable tool, providing reliable estimates of aboveground biomass (AGB). The overall goal of this study was to develop a method for assessing AGB using a synergy of low point density LiDAR-derived point cloud data and multi-spectral imagery in conifer-dominated forest in the southwest of Sweden. Different treetop detection algorithms were applied for forest inventory parameter extraction from a LiDAR-derived canopy height model. Estimation of AGB was based on the power functions derived from tree parameters measured in the field, while vegetation classification of a multi-spectral image (SPOT-5) was performed in order to account for dependences of AGB estimates on vegetation types. Linear regression confirmed good performance of a newly developed grid-based approach for biomass estimation (R2 = 0.80). Results showed AGB to vary from below 1 kg/m2 in very young forests to 94 kg/m2 in mature spruce forests, with RMSE of 4.7 kg/m2. These AGB estimates build a basis for further studies on carbon stocks as well as for monitoring this forest ecosystem in respect of disturbance and change in time. The methodology developed in this study can be easily adopted for assessing biomass of other conifer-dominated forests on the basis of low-density LiDAR and multispectral imagery. This methodology is hence of much wider applicability than biomass derivation based on expensive and currently still scarce high-density LiDAR data.
      PubDate: 2014-05-21
      DOI: 10.3390/f5050992
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 1011-1031: Assessment of Low Density Full-Waveform
           Airborne Laser Scanning for Individual Tree Detection and Tree Species
           Classification

    • Authors: Xiaowei Yu, Paula Litkey, Juha Hyyppä, Markus Holopainen, Mikko Vastaranta
      Pages: 1011 - 1031
      Abstract: The paper investigated the possible gains in using low density (average 1 pulse/m2) full-waveform (FWF) airborne laser scanning (ALS) data for individual tree detection and tree species classification and compared the results to the ones obtained using discrete return laser scanning. The aim is to approach a low-cost, fully ALS-based operative forest inventory method that is capable of providing species-specific diameter distributions required for wood procurement. The point data derived from waveform data were used for individual tree detection (ITD). Features extracted from segmented tree objects were used in random forest classification by which both feature selection and classification were performed. Experiments were conducted with 5532 ground measured trees from 292 sample plots and using FWF data collected with Leica ALS60 scanner over a boreal forest, mainly consisting of pine, spruce and birch, in southern Finland. For the comparisons, system produced multi-echo discrete laser data (DSC) were also analyzed with the same procedures. The detection rate of individual trees was slightly higher using FWF point data than DSC point data. Overall detection accuracy, however, was similar because commission error was increased when omission error was decreasing. The best overall classification accuracy was 73.4% which contains an 11 percentage points increase when FWF features were included in the classification compared with DSC features alone. The results suggest that FWF ALS data contains more information about the structure and physical properties of the environment that can be used in tree species classification of pine, spruce and birch when comparing with DSC ALS data.
      PubDate: 2014-05-21
      DOI: 10.3390/f5051011
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 1032-1052: Urban-Tree-Attribute Update Using
           Multisource Single-Tree Inventory

    • Authors: Ninni Saarinen, Mikko Vastaranta, Ville Kankare, Topi Tanhuanpää, Markus Holopainen, Juha Hyyppä, Hannu Hyyppä
      Pages: 1032 - 1052
      Abstract: The requirements for up-to-date tree data in city parks and forests are increasing, and an important question is how to keep the digital databases current for various applications. Traditional map-updating procedures, such as visual interpretation of digital aerial images or field measurements using tachymeters, are either inaccurate or expensive. Recently, the development of laser-scanning technology has opened new opportunities for tree mapping and attributes updating. For a detailed measurement and attributes update of urban trees, we tested the use of a multisource single-tree inventory (MS-STI) for heterogeneous urban forest conditions. MS-STI requires an existing tree map as input information in addition to airborne laser-scanning (ALS) data. In our study, the tested input tree map was produced by terrestrial laser scanning (TLS) and by using a Global Navigation Satellite System (GNSS). Tree attributes were either measured from ALS or predicted by using metrics extracted from ALS data. Stem diameter-at-breast height (DBH) was predicted and compared to the field measures, and tree height and crown area were directly measured from ALS data at the two different urban-forest areas. The results indicate that MS-STI can be used for updating urban-forest attributes. The accuracies of DBH estimations were improved compared to the existing attribute information in the city of Helsinki’s urban-tree register. In addition, important attributes, such as tree height and crown dimensions, were extracted from ALS and added as attributes to the urban-tree register.
      PubDate: 2014-05-22
      DOI: 10.3390/f5051032
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 1053-1068: Using VEGNET In-Situ Monitoring LiDAR
           (IML) to Capture Dynamics of Plant Area Index, Structure and Phenology in
           Aspen Parkland Forests in Alberta, Canada

    • Authors: Carlos Portillo-Quintero, Arturo Sanchez-Azofeifa, Darius Culvenor
      Pages: 1053 - 1068
      Abstract: The use of ceptometers and digital hemispherical photographs to estimate Plant Area Index (PAI) often include biases and errors from instrument positioning, orientation and data analysis. As an alternative to these methods, we used an In-Situ Monitoring LiDAR system that provides indirect measures of PAI and Plant Area Volume Density (PAVD) at a fixed angle, based on optimized principles and algorithms for PAI retrieval. The instrument was installed for 22 nights continuously from September 26 to October 17, 2013 during leaf-fall in an Aspen Parkland Forest. A total of 85 scans were performed (~4 scans per night). PAI measured decreased from 1.27 to 0.67 during leaf-fall, which is consistent with values reported in the literature. PAVD profiles allowed differentiating the contribution of PAI per forest strata. Phenological changes were captured in four ways: number of hits, maximum cumulative and absolute PAI values, time series of PAVD profiles and PAI values per forest strata. We also found that VEGNET IML Canopy PAI and MODIS LAI values showed a similar decreasing trend and differed by 2%–15%. Our results indicate that the VEGNET IML has great potential for rapid forest structural characterization and for ground validation of PAI/LAI at a temporal frequency compatible with earth observation satellites.
      PubDate: 2014-05-22
      DOI: 10.3390/f5051053
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 1069-1105: Highly Accurate Tree Models Derived from
           Terrestrial Laser Scan Data: A Method Description

    • Authors: Jan Hackenberg, Christopher Morhart, Jonathan Sheppard, Heinrich Spiecker, Mathias Disney
      Pages: 1069 - 1105
      Abstract: This paper presents a method for fitting cylinders into a point cloud, derived from a terrestrial laser-scanned tree. Utilizing high scan quality data as the input, the resulting models describe the branching structure of the tree, capable of detecting branches with a diameter smaller than a centimeter. The cylinders are stored as a hierarchical tree-like data structure encapsulating parent-child neighbor relations and incorporating the tree’s direction of growth. This structure enables the efficient extraction of tree components, such as the stem or a single branch. The method was validated both by applying a comparison of the resulting cylinder models with ground truth data and by an analysis between the input point clouds and the models. Tree models were accomplished representing more than 99% of the input point cloud, with an average distance from the cylinder model to the point cloud within sub-millimeter accuracy. After validation, the method was applied to build two allometric models based on 24 tree point clouds as an example of the application. Computation terminated successfully within less than 30 min. For the model predicting the total above ground volume, the coefficient of determination was 0.965, showing the high potential of terrestrial laser-scanning for forest inventories.
      PubDate: 2014-05-22
      DOI: 10.3390/f5051069
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 1106-1121: Field Supervisory Test of
           DREB-Transgenic Populus: Salt Tolerance, Long-Term Gene Stability and
           Horizontal Gene Transfer

    • Authors: Nan Lu, Bing Wei, Yuhan Sun, Xin Liu, Shouyi Chen, Wanke Zhang, Yingzhi Zhang, Yun Li
      Pages: 1106 - 1121
      Abstract: Improving saline resistance may be useful for reducing environmental susceptibility and improving yields in poplar plantations. However, the instability of genetically engineered traits and gene transfer reduce their usefulness and commercial value. To investigate whether the foreign gene is still present in the genome of receptor plants after seven years (i.e., long-term foreign gene stability and gene transfer), we randomly analyzed ten field-grown transgenic hybrid Populus ((Populus tomentosa × Populus bolleana) × P. tomentosa) carrying the DREB1 gene from Atriplex hortensis. The results of PCR and tissue culture experiments showed that AhDREB1 was present in the transgenic trees and was still expressed. However, the transcriptional expression level had decreased compared with that four years earlier. The PCR results also indicated no foreign gene in the genomic DNA of microorganisms in the soil near the transgenic poplars, indicating that no significant gene transfer had occurred from the transgenic poplars to the microorganisms at seven years after planting.
      PubDate: 2014-05-22
      DOI: 10.3390/f5051106
      Issue No: Vol. 5, No. 5 (2014)
       
  • Forests, Vol. 5, Pages 557-578: Potential Roles of Swedish Forestry in the
           Context of Climate Change Mitigation

    • Authors: Tomas Lundmark, Johan Bergh, Peter Hofer, Anders Lundström, Annika Nordin, Bishnu Poudel, Roger Sathre, Ruedi Taverna, Frank Werner
      Pages: 557 - 578
      Abstract: In Sweden, where forests cover more than 60% of the land area, silviculture and the use of forest products by industry and society play crucial roles in the national carbon balance. A scientific challenge is to understand how different forest management and wood use strategies can best contribute to climate change mitigation benefits. This study uses a set of models to analyze the effects of different forest management and wood use strategies in Sweden on carbon dioxide emissions and removals through 2105. If the present Swedish forest use strategy is continued, the long-term climate change mitigation benefit will correspond to more than 60 million tons of avoided or reduced emissions of carbon dioxide annually, compared to a scenario with similar consumption patterns in society but where non-renewable products are used instead of forest-based products. On average about 470 kg of carbon dioxide emissions are avoided for each cubic meter of biomass harvested, after accounting for carbon stock changes, substitution effects and all emissions related to forest management and industrial processes. Due to Sweden’s large export share of forest-based products, the climate change mitigation effect of Swedish forestry is larger abroad than within the country. The study also shows that silvicultural methods to increase forest biomass production can further reduce net carbon dioxide emissions by an additional 40 million tons of per year. Forestry’s contribution to climate change mitigation could be significantly increased if management of the boreal forest were oriented towards increased biomass production and if more wood were used to substitute fossil fuels and energy-intensive materials.
      PubDate: 2014-03-26
      DOI: 10.3390/f5040557
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 579-598: Local Participation in REDD+: Lessons from
           the Eastern Brazilian Amazon

    • Authors: Marina Cromberg, Amy Duchelle, Isa Rocha
      Pages: 579 - 598
      Abstract: There are concerns that local people will not be genuinely involved in initiatives to Reduce Emissions from Deforestation and Forest Degradation (REDD+). We analyzed local participation in the design of one REDD+ project in the eastern Brazilian Amazon, and assessed local hopes, worries and recommendations for the project through four community focus groups and interviews with 137 households at the site. Our results showed that only one-third of households interviewed (31%) had enough information about the project to describe it accurately. Of those, the majority (60%) hoped that the project would improve their incomes, followed by improving their agricultural production (33%) and helping protect forests (26%). While increasing household incomes was the dominant hope, people’s recommendations revealed that they favored non-monetary forms of compensation over the direct cash payments included in the proponents’ package of incentives. Their main recommendation was that the project should help improve their production systems through access to technical assistance, machinery and training, while valuing local production systems (46%). Our study highlights the need for participation that goes beyond passive consultation with local people to develop REDD+ interventions that best reflect local knowledge, land use practices and aspirations.
      PubDate: 2014-04-03
      DOI: 10.3390/f5040579
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 599-619: Multi-Scalar Governance for Restoring the
           Brazilian Atlantic Forest: A Case Study on Small Landholdings in Protected
           Areas of Sustainable Development

    • Authors: Alaine Ball, Alice Gouzerh, Pedro Brancalion
      Pages: 599 - 619
      Abstract: Implementation of forest restoration projects requires cross-scale and hybrid forms of governance involving the state, the market, civil society, individuals, communities, and other actors. Using a case study from the Atlantic Forest Hotspot, we examine the governance of a large-scale forest restoration project implemented by an international non-governmental organization (NGO) on family farmer landholdings located within protected areas of sustainable development. In addition to forest restoration, the project aims to provide an economic benefit to participating farmers by including native species with market potential (fruits, timber) in restoration models and by contracting farmers in the planting phase. We employed qualitative methods such as structured interviews and participant observation to assess the effect of environmental policy and multi-scalar governance on implementation and acceptability of the project by farmers. We demonstrate that NGO and farmer expectations for the project were initially misaligned, hampering farmer participation. Furthermore, current policy complicated implementation and still poses barriers to project success, and projects must remain adaptable to changing legal landscapes. We recommend increased incorporation of social science methods in earlier stages of projects, as well as throughout the course of implementation, in order to better assess the needs and perspectives of participants, as well as to minimize trade-offs.
      PubDate: 2014-04-03
      DOI: 10.3390/f5040599
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 620-642: Carbon Stocks and Climate Change:
           Management Implications in Northern Arizona Ponderosa Pine Forests

    • Authors: Benjamin Bagdon, Ching-Hsun Huang
      Pages: 620 - 642
      Abstract: Researchers have observed climate-driven shifts of forest types to higher elevations in the Southwestern US and predict further migration coupled with large-scale mortality events proportional to increases in radiative forcing. Range contractions of forests are likely to impact the total carbon stored within a stand. This study examines the dynamics of Pinus ponderosa stands under three climate change scenarios in Northern Arizona using the Climate Forest Vegetation Simulator (Climate-FVS) model to project changes in carbon pools. A sample of 90 stands were grouped according to three elevational ranges; low- (1951 to 2194 m), mid- (2194 to 2499 m), and high- (2499 to 2682 m.) elevation stands. Growth, mortality, and carbon stores were simulated in the Climate-FVS over a 100 year timespan. We further simulated three management scenarios for each elevational gradient and climate scenario. Management included (1) a no-management scenario, (2) an intensive-management scenario characterized by thinning from below to a residual basal area (BA) of 18 m2/ha in conjunction with a prescribed burn every 10 years, and (3) a moderate-management scenario characterized by a thin-from-below treatment to a residual BA of 28 m2/ha coupled with a prescribed burn every 20 years. Results indicate that any increase in aridity due to climate change will produce substantial mortality throughout the elevational range of ponderosa pine stands, with lower elevation stands projected to experience the most devastating effects. Management was only effective for the intensive-management scenario; stands receiving this treatment schedule maintained moderately consistent levels of basal area and demonstrated a higher level of resilience to climate change relative to the two other management scenarios. The results of this study indicate that management can improve resiliency to climate change, however, resource managers may need to employ more intensive thinning treatments than currently proposed to achieve the best results.
      PubDate: 2014-04-04
      DOI: 10.3390/f5040620
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 643-665: Nitrogen and Carbon Biogeochemistry in
           Forest Sites along an Indirect Urban–Rural Gradient in Southeastern
           Michigan

    • Authors: Ari Kahan, William Currie, Daniel Brown
      Pages: 643 - 665
      Abstract: To evaluate the impacts of urbanization on soil and vegetation in protected forest areas, 12 forest sites in Southeastern Michigan USA were studied in an indirect urban–rural gradient. Field study plots were established in forest edge zones of each protected area. Significant findings were that in these edge zones of protected areas: (a) soil nitrogen tended to be greater where surrounding housing density was greater; (b) overstory woody biomass and basal area were greater where surrounding housing density was greater; and (c) the study region overall exhibited low soil carbon content (mean 2.71%) and relatively high soil nitrogen content (mean 0.20%), yielding a surprisingly low surface soil C/N ratio (mean 13.4). Overall, 24 woody plant genera were encountered, with the three genera Acer, Carya and Quercus accounting for 83.7% of total biomass and 74.1% of total basal area. No significant relationships were observed between housing density and soil C/N ratio or between housing density and foliar N. Results indicate that a halo of urban-ecological impacts exists in the landscape of Southeastern Michigan, similar to previously studied linear urban–rural gradients in other regions.
      PubDate: 2014-04-04
      DOI: 10.3390/f5040643
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 666-688: Soil Organic Carbon Storage and Stability
           in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA

    • Authors: Mercedes Dobarco, Helga Van Miegroet
      Pages: 666 - 688
      Abstract: To assess the potential impact of conifer encroachment on soil organic carbon (SOC) dynamics and storage in montane aspen-conifer forests from the interior western US, we sampled mineral soils (0–15 cm) across the aspen-conifer ecotones in southern and northern Utah and quantified total SOC stocks, stable SOC (i.e., mineral-associated SOC (MoM)), labile SOC (i.e., light fraction (LF), decomposable (CO2 release during long-term aerobic incubations) and soluble SOC (hot water extractable organic carbon (HWEOC)). Total SOC storage (47.0 ± 16.5 Mg C ha−1) and labile SOC as LF (14.0 ± 7.10 Mg C ha−1), SOC decomposability (cumulative released CO2-C of 5.6 ± 3.8 g C g−1 soil) or HWEOC (0.6 ± 0.6 mg C g−1 soil) did not differ substantially with vegetation type, although a slight increase in HWEOC was observed with increasing conifer in the overstory. There were statistically significant differences (p = 0.035) in stable MoM storage, which was higher under aspen (31.2 ± 15.1 Mg C ha−1) than under conifer (22.8 ± 9.0 Mg C ha−1), with intermediate values under mixed (25.7 ± 8.8 Mg C ha−1). Texture had the greatest impact on SOC distribution among labile and stable fractions, with increasing stabilization in MoM and decreasing bio-availability of SOC with increasing silt + clay content. Only at lower silt + clay contents (40%–70%) could we discern the influence of vegetation on MoM content. This highlights the importance of chemical protection mechanisms for long-term C sequestration.
      PubDate: 2014-04-08
      DOI: 10.3390/f5040666
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 689-714: Repeated Raking of Pine Plantations Alters
           Soil Arthropod Communities

    • Authors: Holly Ober, Lucas DeGroote
      Pages: 689 - 714
      Abstract: Terrestrial arthropods in forests are engaged in vital ecosystem functions that ultimately help maintain soil productivity. Repeated disturbance can cause abrupt and irreversible changes in arthropod community composition and thereby alter trophic interactions among soil fauna. An increasingly popular means of generating income from pine plantations in the Southeastern U.S. is annual raking to collect pine litter. We raked litter once per year for three consecutive years in the pine plantations of three different species (loblolly, Pinus taeda; longleaf, P. palustris; and slash, P. elliottii). We sampled arthropods quarterly for three years in raked and un-raked pine stands to assess temporal shifts in abundance among dominant orders of arthropods. Effects varied greatly among orders of arthropods, among timber types, and among years. Distinct trends over time were apparent among orders that occupied both high trophic positions (predators) and low trophic positions (fungivores, detritivores). Multivariate analyses demonstrated that raking caused stronger shifts in arthropod community composition in longleaf and loblolly than slash pine stands. Results highlight the role of pine litter in shaping terrestrial arthropod communities, and imply that repeated removal of pine straw during consecutive years is likely to have unintended consequences on arthropod communities that exacerbate over time.
      PubDate: 2014-04-10
      DOI: 10.3390/f5040689
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 715-743: Understory Structure and Vascular Plant
           Diversity in Naturally Regenerated Deciduous Forests and Spruce
           Plantations on Similar Clear-Cuts: Implications for Forest Regeneration
           Strategy Selection

    • Authors: ZhiQiang Fang, WeiKai Bao, XiaoLi Yan, Xin Liu
      Pages: 715 - 743
      Abstract: The active effect of natural regeneration on understory vegetation and diversity on clear-cut forestlands, in contrast to conifer reforestation, is still controversial. Here we investigated differences in understory vegetation by comparing naturally regenerated deciduous forests (NR) and reforested spruce plantations (SP) aged 20–40 years on 12 similar clear-cuts of subalpine old-growth spruce-fir forests from the eastern Tibetan Plateau. We found that 283 of the 334 vascular plant species recorded were present in NR plots, while only 264 species occurred in SP plots. This was consistent with richer species, higher cover, and stem (or shoot) density of tree seedlings, shrubs, and ferns in the NR plots than in the SP plots. Moreover, understory plant diversity was limited under dense canopy cover, which occurred more frequently in the SP plots. Our findings implied that natural deciduous tree regeneration could better preserve understory vegetation and biodiversity than spruce reforestation after clear-cutting. This result further informed practices to reduce tree canopy cover for spruce plantations or to integrate natural regeneration and reforestation for clear-cuts in order to promote understory vegetation and species diversity conservation.
      PubDate: 2014-04-15
      DOI: 10.3390/f5040715
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 744-762: Acoustic Wave Velocity as a Selection
           Trait in Eucalyptus nitens

    • Authors: David Blackburn, Matthew Hamilton, Dean Williams, Chris Harwood, Brad Potts
      Pages: 744 - 762
      Abstract: Previous studies in Eucalyptus nitens have revealed favourable genetic correlations exist between acoustic wave velocity (AWV) in standing trees and modulus of elasticity (MOE), which can determine the suitability of trees for structural timber and/or engineered wood products. This study investigates the strength and stability of genetic variation in standing tree AWV across a range of environments in Tasmania, where there are a number of large plantation estates and breeding trials. Trees under study were from open-pollinated progeny trials established in 1993. Across sites, for standing tree AWV the ranking of E. nitens races did not change and within-race additive genetic correlations were strong (0.61 to 0.99). Heritabilities (0.16 to 0.74) and coefficients of additive genetic variation (2.6 to 4.8) were moderate for this trait. Correlations between standing tree AWV and both basic density and diameter at breast height (DBH) were favourable. Results indicate that there is potential to improve MOE in E. nitens through the exploitation of genetic variation in AWV among and within races, the expression of genetic variation in AWV is relatively stable across different growing environments, and past selection for basic density and growth in pulpwood breeding programs is unlikely to have adversely affected MOE.
      PubDate: 2014-04-16
      DOI: 10.3390/f5040744
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 763-783: A Comparison of Governance Challenges in
           Forest Restoration in Paraguay’s Privately-Owned Forests and
           Madagascar’s Co-managed State Forests

    • Authors: Stephanie Mansourian, Lucy Aquino, Thomas Erdmann, Francisco Pereira
      Pages: 763 - 783
      Abstract: Governance of forest restoration is significantly impacted by who are the owners of and rights holders to the forest. We review two cases, Paraguay’s Atlantic forest and Madagascar’s forests and shrublands, where forest restoration is a priority and where forest ownership and rights are having direct repercussions on forest restoration. In Paraguay where a large proportion of forests are in the hands of private landowners, specific legislation, government incentives, costs and benefits of forest restoration, and the role of international markets for commodities are all key factors, among others, that influence the choice of private landowners to engage or not in forest restoration. On the other hand, in Madagascar’s co-managed state forests, while some similar challenges exist with forest restoration, such as the pressures from international markets, other specific challenges can be identified notably the likely long term impact of investment in forest restoration on land rights, traditional authority, and direct links to elements of human wellbeing. In this paper, we explore and contrast how these different drivers and pressures affect the restoration of forests under these two different property regimes.
      PubDate: 2014-04-21
      DOI: 10.3390/f5040763
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 784-801: The Impact of Windstorm Damage in the
           Assessment of the Carbon Balance in Even-Aged Fagus sylvatica L. Stands

    • Authors: Mathieu Fortin, Axel Albrecht, Ulrich Kohnle, François Ningre
      Pages: 784 - 801
      Abstract: Due to the fact that forest ecosystems can potentially mitigate the impact of climate change, the carbon balance of managed forests has caught the attention of a large scientific community. Some authors conclude that extending rotation lengths would actually favour the climate change mitigation effect since more carbon would be stored in the biomass on the average. However, when the occurrence of catastrophic disturbances such as windstorms is not considered, the advantage of extending the rotation length might be overestimated for some species. In this study, we addressed this issue by coupling a growth model, a windstorm damage model and a carbon assessment tool. The evolution of an even-aged European beech (Fagus sylvatica L.) stand was simulated under three different rotation lengths. Simulations including stochastic windstorm events were run and compared with deterministic simulations with no catastrophic disturbance. Our results indicate that when disturbances caused by storms were not taken into account, the carbon balance was actually overestimated in some cases and that this overestimation increased with the rotation length. In our case study, omitting windstorm damage resulted in an overestimation as large as 8% for the longer rotation length. Nevertheless, when windstorm damage was taken into account in the simulation, the longer rotation length still stored more carbon on the average than shorter rotation lengths. However, the marginal gain in carbon storage induced by the increase of the rotation length was reduced.
      PubDate: 2014-04-21
      DOI: 10.3390/f5040784
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 802-821: Impacts of Frequent Burning on Live Tree
           Carbon Biomass and Demography in Post-Harvest Regrowth Forest

    • Authors: Luke Collins, Trent Penman, Fabiano Ximenes, Doug Binns, Alan York, Ross Bradstock
      Pages: 802 - 821
      Abstract: The management of forest ecosystems to increase carbon storage is a global concern. Fire frequency has the potential to shift considerably in the future. These shifts may alter demographic processes and growth of tree species, and consequently carbon storage in forests. Examination of the sensitivity of forest carbon to the potential upper and lower extremes of fire frequency will provide crucial insight into the magnitude of possible change in carbon stocks associated with shifts in fire frequency. This study examines how tree biomass and demography of a eucalypt forest regenerating after harvest is affected by two experimentally manipulated extremes in fire frequency (i.e., ~3 year fire intervals vs. unburnt) sustained over a 23 year period. The rate of post-harvest biomass recovery of overstorey tree species, which constituted ~90% of total living tree biomass, was lower within frequently burnt plots than unburnt plots, resulting in approximately 20% lower biomass in frequently burnt plots by the end of the study. Significant differences in carbon biomass between the two extremes in frequency were only evident after >15–20 years of sustained treatment. Reduced growth rates and survivorship of smaller trees on the frequently burnt plots compared to unburnt plots appeared to be driving these patterns. The biomass of understorey trees, which constituted ~10% of total living tree biomass, was not affected by frequent burning. These findings suggest that future shifts toward more frequent fire will potentially result in considerable reductions in carbon sequestration across temperate forest ecosystems in Australia.
      PubDate: 2014-04-22
      DOI: 10.3390/f5040802
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 822-826: A Comment on “Management for
           Mountain Pine Beetle Outbreak Suppression: Does Relevant Science Support
           Current Policy'”

    • Authors: Christopher Fettig, Kenneth Gibson, A. Munson, Jose Negrón
      Pages: 822 - 826
      Abstract: There are two general approaches for reducing the negative impacts of mountain pine beetle, Dendroctonus ponderosae Hopkins, on forests. Direct control involves short-term tactics designed to address current infestations by manipulating mountain pine beetle populations, and includes the use of fire, insecticides, semiochemicals, sanitation harvests, or a combination of these treatments. Indirect control is preventive, and designed to reduce the probability and severity of future infestations within treated areas by manipulating stand, forest and/or landscape conditions by reducing the number of susceptible host trees through thinning, prescribed burning, and/or alterations of age classes and species composition. We emphasize that “outbreak suppression” is not the intent or objective of management strategies implemented for mountain pine beetle in the western United States, and that the use of clear, descriptive language is important when assessing the merits of various treatment strategies.
      PubDate: 2014-04-22
      DOI: 10.3390/f5040822
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 827-846: Interactions between Fine Wood
           Decomposition and Flammability

    • Authors: Weiwei Zhao, Luke Blauw, Richard van Logtestijn, William Cornwell, Johannes Cornelissen
      Pages: 827 - 846
      Abstract: Fire is nearly ubiquitous in the terrestrial biosphere, with profound effects on earth surface carbon storage, climate, and forest functions. Fuel quality is an important parameter determining forest fire behavior, which differs among both tree species and organs. Fuel quality is not static: when dead plant material decomposes, its structural, chemical, and water dynamic properties change, with implications for fuel flammability. However, the interactions between decomposition and flammability are poorly understood. This study aimed to determine decomposition’s effects on fuel quality and how this directly and indirectly affects wood flammability. We did controlled experiments on water dynamics and fire using twigs of four temperate tree species. We found considerable direct and indirect effects of decomposition on twig flammability, particularly on ignitability and burning time, which are important variables for fire spread. More decomposed twigs ignite and burn faster at given water content. Moreover, decomposed twigs dry out faster than fresh twigs, which make them flammable sooner when drying out after rain. Decomposed fine woody litters may promote horizontal fire spread as ground fuels and act as a fuel ladder when staying attached to trees. Our results add an important, previously poorly studied dynamic to our understanding of forest fire spread.
      PubDate: 2014-04-22
      DOI: 10.3390/f5040827
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 847-861: Accountable Accounting: Carbon-Based
           Management on Marginal Lands

    • Authors: Tara DiRocco, Benjamin Ramage, Samuel Evans, Matthew Potts
      Pages: 847 - 861
      Abstract: Substantial discussion exists concerning the best land use options for mitigating greenhouse gas (GHG) emissions on marginal land. Emissions-mitigating land use options include displacement of fossil fuels via biofuel production and afforestation. Comparing C recovery dynamics under these different options is crucial to assessing the efficacy of offset programs. In this paper, we focus on forest recovery on marginal land, and show that there is substantial inaccuracy and discrepancy in the literature concerning carbon accumulation. We find that uncertainty in carbon accumulation occurs in estimations of carbon stocks and models of carbon dynamics over time. We suggest that analyses to date have been largely unsuccessful at determining reliable trends in site recovery due to broad land use categories, a failure to consider the effect of current and post-restoration management, and problems with meta-analysis. Understanding of C recovery could be greatly improved with increased data collection on pre-restoration site quality, prior land use history, and management practices as well as increased methodological standardization. Finally, given the current and likely future uncertainty in C dynamics, we recommend carbon mitigation potential should not be the only environmental service driving land use decisions on marginal lands.
      PubDate: 2014-04-23
      DOI: 10.3390/f5040847
      Issue No: Vol. 5, No. 4 (2014)
       
  • Forests, Vol. 5, Pages 384-403: Estimating Single-Tree Crown Biomass of
           Norway Spruce by Airborne Laser Scanning: A Comparison of Methods with and
           without the Use of Terrestrial Laser Scanning to Obtain the Ground
           Reference Data

    • Authors: Marius Hauglin, Terje Gobakken, Rasmus Astrup, Liviu Ene, Erik Næsset
      Pages: 384 - 403
      Abstract: Several methods to conduct single-tree inventories using airborne laser scanning (ALS) have been proposed, and even terrestrial laser scanning (TLS) has recently emerged as a possible tool for the collection of forest inventory data. In the present study, a novel methodological framework for a combined use of ALS and TLS in an inventory was tested and compared to a method without the use of TLS. Single-tree Norway spruce crown biomass was predicted using an ALS-model with training data obtained by TLS. ALS and TLS data were collected for sets of sample trees, including 68 trees with both ALS and TLS data. In total, 29 destructively sampled trees were used to fit a TLS crown biomass model, which then was used to predict crown biomass in a separate set of 68 trees. This dataset was subsequently used to fit an ALS crown biomass model. When validating the model, using a separate dataset with accurately measured crown biomass obtained through destructive sampling, the mean error was 32% of the observed mean biomass. Corresponding crown biomass predictions derived with ALS-predicted diameters and the use of conventional and existing allometric models resulted in a mean error of 35%. Thus, in the present study, a slight improvement, in terms of prediction accuracy, was found when using training data with ground reference values obtained by TLS.
      PubDate: 2014-02-28
      DOI: 10.3390/f5030384
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 404-424: Do PES Improve the Governance of Forest
           Restoration'

    • Authors: Romain Pirard, Guillaume de Buren, Renaud Lapeyre
      Pages: 404 - 424
      Abstract: Payments for Environmental Services (PES) are praised as innovative policy instruments and they influence the governance of forest restoration efforts in two major ways. The first is the establishment of multi-stakeholder agencies as intermediary bodies between funders and planters to manage the funds and to distribute incentives to planters. The second implication is that specific contracts assign objectives to land users in the form of conditions for payments that are believed to increase the chances for sustained impacts on the ground. These implications are important in the assessment of the potential of PES to operate as new and effective funding schemes for forest restoration. They are analyzed by looking at two prominent payments for watershed service programs in Indonesia—Cidanau (Banten province in Java) and West Lombok (Eastern Indonesia)—with combined economic and political science approaches. We derive lessons for the governance of funding efforts (e.g., multi-stakeholder agencies are not a guarantee of success; mixed results are obtained from a reliance on mandatory funding with ad hoc regulations, as opposed to voluntary contributions by the service beneficiary) and for the governance of financial expenditure (e.g., absolute need for evaluation procedures for the internal governance of farmer groups). Furthermore, we observe that these governance features provide no guarantee that restoration plots with the highest relevance for ecosystem services are targeted by the PES.
      PubDate: 2014-03-17
      DOI: 10.3390/f5030404
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 425-438: Soil Carbon Dynamics in Residential Lawns
           Converted from Appalachian Mixed Oak Stands

    • Authors: Chad Campbell, John Seiler, P. Wiseman, Brian Strahm, John Munsell
      Pages: 425 - 438
      Abstract: The conversion of unmanaged forest land to homesites dominated by managed turfgrass lawns continues to increase and has large potential impacts on biogeochemical cycling. The conversion process from forest into mowed turfgrass involves a major disturbance to soil properties and shift in ecological conditions, which could affect soil physical, chemical and biological properties, including carbon sequestration. We conducted a study on 64 residential properties, ranging from 5 to 52 years since development, to compare soil carbon content, bulk density, temperature, and moisture, between lawns and the surrounding forests from which they were converted. Homeowners were surveyed on lawn management practices and environmental attitudes, and the relationships between these and soil properties were investigated. Soil bulk density was significantly higher in the upper 10 cm of lawns compared to adjacent forest (35% higher at 0–5 cm and 15.6% higher at 5–10 cm). Total soil C content to 30 cm of lawn (6.5 kg C m−2) and forest (7.1 kg C m−2) marginally differed (p = 0.08), and lawns contained significantly greater C (0.010 g C cm−3) than forests (0.007 g C cm−3) at the 20–30 cm soil depth (p = 0.0137). In the lawns, there was a positive relationship between time since development and surface (0–5 cm) C concentration (p = 0.04), but a negative relationship at 20–30 cm (p = 0.03). Surface soils also exhibited a positive correlation between fertilization frequency and C (p = 0.0005) content. Lawn management intensity (fertilizer and pesticide use) increased with environmental commitment. Homeowners with a higher environmental commitment had lawns with greater soil carbon levels. Our results indicate that converting unmanaged Appalachian hardwood forest into managed, turfgrass-dominated residential landscapes may affect C depth distribution, but results in little change in total soil carbon sequestration in the upper 30 cm.
      PubDate: 2014-03-19
      DOI: 10.3390/f5030425
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 439-454: An Overview of Integrated Management of
           Leaf-Cutting Ants (Hymenoptera: Formicidae) in Brazilian Forest
           Plantations

    • Authors: Ronald Zanetti, José Zanuncio, Juliana Santos, Willian da Silva, Genésio Ribeiro, Pedro Lemes
      Pages: 439 - 454
      Abstract: Brazilian forest producers have developed integrated management programs to increase the effectiveness of the control of leaf-cutting ants of the genera Atta and Acromyrmex. These measures reduced the costs and quantity of insecticides used in the plantations. Such integrated management programs are based on monitoring the ant nests, as well as the need and timing of the control methods. Chemical control employing baits is the most commonly used method, however, biological, mechanical and cultural control methods, besides plant resistance, can reduce the quantity of chemicals applied in the plantations.
      PubDate: 2014-03-20
      DOI: 10.3390/f5030439
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 455-465: Cellulolytic Bacteria Associated with the
           Gut of Dendroctonus armandi Larvae (Coleoptera: Curculionidae: Scolytinae)
           

    • Authors: Xia Hu, Jiamin Yu, Chunyan Wang, Hui Chen
      Pages: 455 - 465
      Abstract: The object of this study was to investigate the cellulolytic bacterial community in the intestine of the Chinese white pine beetle (Dendroctonus armandi) larvae. A total of 91 cellulolytic bacteria were isolated and assigned to 11 genotypes using amplified ribosomal DNA restriction analysis (ARDRA). Partial 16S rDNA sequence analysis and morphological tests were used to assign the 11 representative isolates. The results showed that the isolates belonged to α-Proteobacteria, γ-Proteobacteria and Firmicutes. Members of γ-Proteobacteria were the most frequently represented species and accounted for 73.6% of all the cellulolytic bacteria. The majority of cellulolytic bacteria in D. armandi larva gut were identified as Serratia and accounted for 49.5%, followed by Pseudomonas, which accounted for 22%. In addition, members of Bacillus, Brevundimonas, Paenibacillus, Pseudoxanthomonas, Methylobacterium and Sphingomonas were found in the D. armandi larva gut. Brevundimonas kwangchunensis, Brevundimonas vesicularis, Methylobacterium populi and Pseudoxanthomonas mexicana were reported to be cellulolytic for the first time in this study. Information generated from the present study might contribute towards understanding the relationship between bark beetle and its gut flora.
      PubDate: 2014-03-21
      DOI: 10.3390/f5030455
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 466-481: Comparison of Pyrolysis Mass Spectrometry
           and Near Infrared Spectroscopy for Genetic Analysis of Lignocellulose
           Chemical Composition in Populus

    • Authors: Jianxing Zhang, Evandro Novaes, Matias Kirst, Gary Peter
      Pages: 466 - 481
      Abstract: Genetic analysis of wood chemical composition is often limited by the cost and throughput of direct analytical methods. The speed and low cost of Fourier transform near infrared (FT-NIR) overcomes many of these limitations, but it is an indirect method relying on calibration models that are typically developed and validated with small sample sets. In this study, we used >1500 young greenhouse grown trees from a clonally propagated single Populus family, grown at low and high nitrogen, and compared FT-NIR calibration sample sizes of 150, 250, 500 and 750 on calibration and prediction model statistics, and heritability estimates developed with pyrolysis molecular beam mass spectrometry (pyMBMS) wood chemical composition. As calibration sample size increased from 150 to 750, predictive model statistics improved slightly. Overall, stronger calibration and prediction statistics were obtained with lignin, S-lignin, S/G ratio, and m/z 144 (an ion from cellulose), than with C5 and C6 carbohydrates, and m/z 114 (an ion from xylan). Although small differences in model statistics were observed between the 250 and 500 sample calibration sets, when predicted values were used for calculating genetic control, the 500 sample set gave substantially more similar results to those obtained with the pyMBMS data. With the 500 sample calibration models, genetic correlations obtained with FT-NIR and pyMBMS methods were similar. Quantitative trait loci (QTL) analysis with pyMBMS and FT-NIR predictions identified only three common loci for lignin traits. FT-NIR identified four QTLs that were not found with pyMBMS data, and these QTLs were for the less well predicted carbohydrate traits.
      PubDate: 2014-03-21
      DOI: 10.3390/f5030466
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 482-497: From Target to Implementation:
           Perspectives for the International Governance of Forest Landscape
           Restoration

    • Authors: Till Pistorius, Horst Freiberg
      Pages: 482 - 497
      Abstract: Continuing depletion of forest resources, particularly in tropical developing countries, has turned vast areas of intact ecosystems into urbanized and agricultural lands. The degree of degradation varies, but in most cases, the ecosystem functions and the ability to provide a variety of ecosystem services are severely impaired. In addition to many other challenges, successful forest restoration of these lands requires considerable resources and funding, but the ecological, economic and social benefits have the potential to outweigh the investment. As a consequence, at the international policy level, restoration is seen as a field of land use activities that provides significant contributions to simultaneously achieving different environmental and social policy objectives. Accordingly, different policy processes at the international policy level have made ecological landscape restoration a global priority, in particular the Convention on Biological Diversity with the Aichi Target 15 agreed upon in 2010, which aims at restoring 15% of all degraded land areas by 2020. While such ambitious policy targets are important for recognizing and agreeing upon solutions for environmental problems, they are unlikely to be further substantiated or governed. The objective of this paper is thus to develop a complementary governance approach to the top-down implementation of the Aichi target. Drawing on collaborative and network governance theories, we discuss the potential of a collaborative networked governance approach and perspectives for overcoming the inherent challenges facing a rapid large-scale restoration of degraded lands.
      PubDate: 2014-03-24
      DOI: 10.3390/f5030482
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 498-517: Effects of Restoration Techniques on Soil
           Carbon and Nitrogen Dynamics in Florida Longleaf Pine (Pinus palustris)
           Sandhill Forests

    • Authors: Martin Lavoie, Michelle Mack, John Hiers, Scott Pokswinski, Analie Barnett, Louis Provencher
      Pages: 498 - 517
      Abstract: Historic fire suppression and intensive forest management in longleaf pine (Pinus palustris) sandhill forests has resulted in hardwood encroachment and degradation of this fire-dependent ecosystem. Active management is now required to restore native community structure and composition, but little is known about the long-term impacts of typical restoration techniques on ecosystem properties. In 1994, the Longleaf Pine Restoration Project (LPRP) was established in fire-excluded longleaf pine sandhills of Eglin Air Force Base, Florida, to explore the effects of restoration treatments on plant and animal community composition and soil processes. Experimental treatments applied included three hardwood reduction techniques and delayed burn. Reference sites were concurrently monitored. Fifteen years later, we revisited the LPRP plots to determine whether soil processes showed lasting treatment effects. This study showed that there were no differences in soil C and N between the reference and the fire-suppressed plots prior to the treatments, suggesting that soil C and N were relatively resistant to degradation. This study also showed that the restoration treatments had a significant effect by reducing soil C, but this effect was only short-lived (<3 years). In addition, a MRPP (multi-response permutation procedure) analysis showed that only the herbicide treatment was still different from the reference plots 15 years after the initial treatments. Thus, this study suggests that repeated fires (or lack of) or hardwood removal treatments have little detectable effect on soil nutrients in these nutrient-poor ecosystems.
      PubDate: 2014-03-24
      DOI: 10.3390/f5030498
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 518-534: Process-Based Modeling to Assess the
           Effects of Recent Climatic Variation on Site Productivity and Forest
           Function across Western North America

    • Authors: Richard Waring, Nicholas Coops, Amanda Mathys, Thomas Hilker, Greg Latta
      Pages: 518 - 534
      Abstract: A process-based forest growth model, 3-PG (Physiological Principles Predicting Growth), parameterized with values of soil properties constrained by satellite-derived estimates of maximum leaf area index (LAImax), was run for Douglas-fir (Pseudotsuga menziesii) to contrast the extent to which site growth potential might vary across western North America between a cool, wet period (1950–1975) and a more recent, generally warmer and drier one (2000–2009). LAImax represents a surrogate for overall site growth potential, as demonstrated from a strong correlation between the two variables, with the latter based on the culmination of mean annual increment estimates made at 3356 ground-based U.S. Forest Service survey plots across the states of Oregon and Washington. Results indicate that since 2000, predicted LAImax has decreased more than 20% in portions of the Southwest USA and for much of the forested area in western Alberta. Similar percentage increases in LAImax were predicted for parts of British Columbia, Idaho and Montana. The modeling analysis included an assessment of changes in seasonal constraints on gross primary production (GPP). A general reduction in limitations caused by spring frost occurred across the entire study area. This has led to a longer growing season, along with notable increases in summer evaporative demand and soil drought for much of the study area away from the maritime influence of the Pacific Ocean.
      PubDate: 2014-03-24
      DOI: 10.3390/f5030518
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 535-556: Biomass Equations for Tropical Forest Tree
           Species in Mozambique

    • Authors: Rosta Mate, Tord Johansson, Almeida Sitoe
      Pages: 535 - 556
      Abstract: Chanfuta (Afzelia quanzensis Welw.), Jambire (Millettia stuhlmannii Taub.) and Umbila (Pterocarpus angolensis D.C.) are, among others, three of the main tropical tree species producing commercial timber in Mozambique. The present study employed destructive biomass estimation methods at three localities in Mozambique (Inhaminga, Mavume, and Tome) to acquire data on the mean diameter at breast height (DBH), and height of trees sampled in 21 stands each of Chanfuta and Jambire, and 15 stands of Umbila. Mean diameter at breast height (DBH) (ob) for Chanfuta, Jambire, and Umbila was: 33.8 ± 12.6 (range 13.5–61.1), 33.4 ± 7.4 (range 21.0–52.2), and 27.0 ± 9.5 (range 14.0–46.5) cm. The mean total values for biomass (kg) of trees of Chanfuta, Jambire, and Umbila trees were 864, 1016, and 321 respectively. The mean percentages of total tree biomass as stem, branch and leaf respectively were 54, 43, and 3 for Chanfuta; 77, 22, and 1 for Jambire; and 46, 51, and 3 for Umbila. The best fit species-specific equation for estimating total above ground biomass (AGB) was the power equation with only DBH considered as independent variable yielding coefficient of determination (R2) ranging from 0.89 to 0.97. At stand level, a total mean of 27.3 tons ha−1 biomass was determined of which studied species represented 94.6%. At plot level, total mean biomass for Jambire was 11.8 tons ha−1, Chanfuta and Umbila 9.9 and 4.1 tons ha−1 respectively. The developed power equation fitted total and stem biomass data well and could be used for biomass prediction of the studied species in Mozambique.
      PubDate: 2014-03-24
      DOI: 10.3390/f5030535
      Issue No: Vol. 5, No. 3 (2014)
       
  • Forests, Vol. 5, Pages 214-233: Local Dynamics Driving Forest Transition:
           Insights from Upland Villages in Southwest China

    • Authors: Jun He, Rong Lang, Jianchu Xu
      Pages: 214 - 233
      Abstract: China has experienced extensive forest transition, from net deforestation to net forestation. Existing theories have highlighted economic growth, the intensification of agriculture and forest scarcity as the pathways of this transition, and studies, in particular from China, have also highlighted the contribution of a huge state afforestation program and the improved implementation and enforcement of forest protection policy and law. However, few studies have paid attention to local dynamics to provide a contextualized understanding of how forest transition has taken place at the local level and the significance of local factors in this change. This paper examines forest transition pathways in two villages in China. We consider the historical perspective and compare their local dynamics and variations to reach an understanding of the process of forest recovery at the local level. The results show that state forestry policies, including afforestation policy and tenure reform, arguably contribute to forest increase, while local processes including livelihood change and institutional factors play a key role in driving and shaping forest transition. We argue that there is a need for local-level studies and recommend including local institutions in forest transition analysis, contextualizing the socio-ecological interactions within the broader concept of political economy.
      PubDate: 2014-01-23
      DOI: 10.3390/f5020214
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 234-255: Tenure Issues in REDD+ Pilot Project Sites
           in Tanzania

    • Authors: Therese Dokken, Susan Caplow, Arild Angelsen, William Sunderlin
      Pages: 234 - 255
      Abstract: REDD+ has been proposed as a viable option for addressing climate change in the near term, and at relatively low cost. There is a broad consensus that clearly defined tenure rights are important for the implementation and success of REDD+, both to manage forests effectively and to protect local communities’ livelihoods. We use primary data from 23 villages in six REDD+ pilot sites in Tanzania to identify causes of deforestation and forest degradation, and tenure rights issues, at the village level prior to project implementation. Further, interviews with project proponents and examination of project documents yields insights into how the proponents plan to address tenure issues. Most villages perceive their tenure as secure and have exclusion rights, while collective action challenges are prevalent in villages experiencing deforestation and forest degradation. These findings suggest that the main tenure issues are related to internal institutional arrangements. While we find that tenure is high on the agenda for all the project proponents, they are mainly focusing on formalization and securing tenure rights from state to community level. Though we do find this to be a precondition for reducing deforestation and degradation, some of their focus should be shifted to strengthening village institutions and enhancing internal compliance.
      PubDate: 2014-02-20
      DOI: 10.3390/f5020234
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 256-268: Structure and Composition of Old-Growth
           and Unmanaged Second-Growth Riparian Forests at Redwood National Park, USA
           

    • Authors: Christopher Keyes, Emily Teraoka
      Pages: 256 - 268
      Abstract: Restoration of second-growth riparian stands has become an important issue for managers of redwood (Sequoia sempervirens [D. Don] Endl.) forest reserves. Identifying differences between old-growth and second-growth forest vegetation is a necessary step in evaluating restoration needs and targets. The objective of this study was to characterize and contrast vegetation structure and composition in old-growth and unmanaged second-growth riparian forests in adjacent, geomorphologically similar watersheds at Redwood National Park. In the old-growth, redwood was the dominant overstory species in terms of stem density, basal area, and importance values. Second-growth was dominated by red alder (Alnus rubra Bong.), Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco), and redwood. Understory species were similar in both forests, with several key differences: Oxalis oregana Nutt. and Trillium ovatum Pursh had greater importance values in the old-growth, and Vaccinium parvifolium Sm., Dryopteris spp. and sedges Carex spp. had greater importance values in the second-growth. Notable differences in structure and composition suggest that restoration practices such as thinning could expedite the acquisition of old-growth characteristics in second-growth riparian forests.
      PubDate: 2014-02-20
      DOI: 10.3390/f5020256
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 269-286: Spatial Characteristics of Edible Wild
           Fern Harvesting in Mountainous Villages in Northeastern Japan Using GPS
           Tracks

    • Authors: Toshiya Matsuura, Ken Sugimura, Asako Miyamoto, Hiroshi Tanaka, Nobuhiko Tanaka
      Pages: 269 - 286
      Abstract: Wild plants in forests provide valuable living resources for rural communities. The location where local people harvest various species is important to the wise use of forest ecosystem services. Using global positioning system (GPS) tracking of harvesters’ activities as well as geographic information system (GIS) and a generalized linear model (GLM), this study analyzed the spatial differences among harvesting sites of three popular edible ferns, i.e., ostrich fern (Matteuccia struthiopteris), bracken (Pteridium aquilinum), and royal fern (Osmunda japonica), in mountainous villages of Northeastern Japan. The explanatory variables used were vegetation classes, terrain features, and proximity to roadways. The GLM yielded clear differences in harvesting sites among species that were affected by both the species’ ecological characteristics and human behavior. Ostrich fern was harvested mainly in canopy openings along valley floors, whereas royal fern harvest sites were frequently located in snow avalanche scrublands. Bracken was mainly harvested in deforested areas or young conifer plantations. Whereas ostrich fern and bracken harvest sites were restricted by the accessibility from roadways, this was not the case for royal fern. Potential harvest sites of ferns were estimated with the highest value for bracken. Our results suggest that local harvesters seriously consider various natural and anthropogenic factors to maintain effective and sustainable harvesting.
      PubDate: 2014-02-20
      DOI: 10.3390/f5020269
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 287-308: High NDVI and Potential Canopy
           Photosynthesis of South American Subtropical Forests despite Seasonal
           Changes in Leaf Area Index and Air Temperature

    • Authors: Piedad Cristiano, Nora Madanes, Paula Campanello, Débora di Francescantonio, Sabrina Rodríguez, Yong-Jiang Zhang, Laureano Carrasco, Guillermo Goldstein
      Pages: 287 - 308
      Abstract: The canopy photosynthesis and carbon balance of the subtropical forests are not well studied compared to temperate and tropical forest ecosystems. The main objective of this study was to assess the seasonal dynamics of Normalized Difference Vegetation Index (NDVI) and potential canopy photosynthesis in relation to seasonal changes in leaf area index (LAI), chlorophyll concentration, and air temperatures of NE Argentina subtropical forests throughout the year. We included in the analysis several tree plantations (Pinus, Eucalyptus and Araucaria species) that are known to have high productivity. Field studies in native forests and tree plantations were conducted; stem growth rates, LAI and leaf chlorophyll concentration were measured. MODIS satellite-derived LAI (1 km SIN Grid) and NDVI (250m SIN Grid) from February 2000 to 2012 were used as a proxy of seasonal dynamics of potential photosynthetic activity at the stand level. The remote sensing LAI of the subtropical forests decreased every year from 6 to 5 during the cold season, similar to field LAI measurements, when temperatures were 10 °C lower than during the summer. The yearly maximum NDVI values were observed during a few months in autumn and spring (March through May and November, respectively) because high and low air temperatures may have a small detrimental effect on photosynthetic activity during both the warm and the cold seasons. Leaf chlorophyll concentration was higher during the cold season than the warm season which may have a compensatory effect on the seasonal variation of the NDVI values. The NDVI of the subtropical forest stands remained high and fairly constant throughout the year (the intra-annual coefficient of variation was 1.9%), and were comparable to the values of high-yield tree plantations. These results suggest that the humid subtropical forests in NE Argentina potentially could maintain high canopy photosynthetic activity throughout the year and thus this ecosystem may be a large carbon sink.
      PubDate: 2014-02-20
      DOI: 10.3390/f5020287
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 309-324: Individual-Based Allometric Equations
           Accurately Measure Carbon Storage and Sequestration in Shrublands

    • Authors: Norman Mason, Peter Beets, Ian Payton, Larry Burrows, Robert Holdaway, Fiona Carswell
      Pages: 309 - 324
      Abstract: Many studies have quantified uncertainty in forest carbon (C) storage estimation, but there is little work examining the degree of uncertainty in shrubland C storage estimates. We used field data to simulate uncertainty in carbon storage estimates from three error sources: (1) allometric biomass equations; (2) measurement errors of shrubs harvested for the allometry; and (3) measurement errors of shrubs in survey plots. We also assessed uncertainty for all possible combinations of these error sources. Allometric uncertainty had the greatest independent effect on C storage estimates for individual plots. The largest error arose when all three error sources were included in simulations (where the 95% confidence interval spanned a range equivalent to 40% of mean C storage). Mean C sequestration (1.73 Mg C ha–1 year–1) exceeded the margin of error produced by the simulated sources of uncertainty. This demonstrates that, even when the major sources of uncertainty were accounted for, we were able to detect relatively modest gains in shrubland C storage.
      PubDate: 2014-02-21
      DOI: 10.3390/f5020309
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 325-346: A Biogeochemical Examination of
           Ontario’s Boreal Forest Ecosite Classification System

    • Authors: Aaron Tamminga, Neal Scott, Paul Treitz, Murray Woods
      Pages: 325 - 346
      Abstract: The ecosite unit in Ontario’s boreal forest ecological land classification system is a polygon of common vegetation type and soil conditions intended to provide a standardized provincial framework to inform meso-scale forestry and planning applications. To determine whether the physical factors used for ecosite classification relate to patterns in ecological function over finer spatial scales, we examined 14 soil properties in replicate boreal forest plots representing eight mineral soil ecosite classes and three organic soil ecosite classes in the Hearst Forest. Despite large differences in vegetation composition, we found few statistically significant differences in properties when compared for individual classes or for more general groupings based on vegetation type and soil texture or expected fertility status. However, some properties (soil organic carbon, total nitrogen, and C:N ratio) were approaching significance in the 0–10 cm depth increment, and there were distinct differences between organic soil and mineral soil sites. Overall, these results suggest few explicit links between ecosystem function and ecosite class at this scale of measurement, highlighting the potential importance of non-steady-state relationships between vegetation species and soil properties in disturbed forests and the potential need for finer-scale characterization to capture patterns in ecosystem function.
      PubDate: 2014-02-21
      DOI: 10.3390/f5020325
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 347-362: Mapping Fusiform Rust Resistance Genes
           within a Complex Mating Design of Loblolly Pine

    • Authors: Tania Quesada, Marcio Resende Jr., Patricio Muñoz, Jill Wegrzyn, David Neale, Matias Kirst, Gary Peter, Salvador Gezan, C. Nelson, John Davis
      Pages: 347 - 362
      Abstract: Fusiform rust resistance can involve gene-for-gene interactions where resistance (Fr) genes in the host interact with corresponding avirulence genes in the pathogen, Cronartium quercuum f.sp. fusiforme (Cqf). Here, we identify trees with Fr genes in a loblolly pine population derived from a complex mating design challenged with two Cqf inocula (one gall and 10 gall mixtures). We used single nucleotide polymorphism (SNP) genotypes at sufficient density to ensure linkage between segregating markers and Fr genes identifying SNPs that explained high proportions of variance in disease incidence using BayesCp, that also were significant using Bayesian Association with Missing Data (BAMD) software. Two SNPs mapped near Fr1 and generated significant LOD scores in single marker regression analyses for Fr1/fr1 parent 17 as well as four other parents. One SNP mapped near Fr8 and was significant for parent 28. Two SNPs mapped to linkage groups not previously shown to contain Fr genes and were significant for three parents. Parent 2 showed evidence of Fr gene stacking. Our results suggest that it is feasible to identify trees segregating for Fr genes, and to map Fr genes, based on parental analysis of SNPs that cosegregate with disease incidence in designed resistance screening trials.
      PubDate: 2014-02-24
      DOI: 10.3390/f5020347
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 363-383: Assessing the Feasibility of Low-Density
           LiDAR for Stand Inventory Attribute Predictions in Complex and Managed
           Forests of Northern Maine, USA

    • Authors: Rei Hayashi, Aaron Weiskittel, Steven Sader
      Pages: 363 - 383
      Abstract: The objective of this study was to evaluate the applicability of using a low-density (1–3 points m−2) discrete-return LiDAR (Light Detection and Ranging) for predicting maximum tree height, stem density, basal area, quadratic mean diameter and total volume. The research was conducted at the Penobscot Experimental Forest in central Maine, where a range of stand structures and species composition is present and generally representative of northern Maine’s forests. Prediction models were developed utilizing the random forest algorithm that was calibrated using reference data collected in fixed radius circular plots. For comparison, the volume model used two sets of reference data, with one being fixed radius circular plots and the other variable radius plots. Prediction biases were evaluated with respect to five silvicultural treatments and softwood species composition based on the coefficient of determination (R2), root mean square error and mean bias, as well as residual scatter plots. Overall, this study found that LiDAR tended to underestimate maximum tree height and volume. The maximum tree height and volume models had R2 values of 86.9% and 72.1%, respectively. The accuracy of volume prediction was also sensitive to the plot type used. While it was difficult to develop models with a high R2, due to the complexities of Maine’s forest structures and species composition, the results suggest that low density LiDAR can be used as a supporting tool in forest management for this region.
      PubDate: 2014-02-24
      DOI: 10.3390/f5020363
      Issue No: Vol. 5, No. 2 (2014)
       
  • Forests, Vol. 5, Pages 21-71: Spruce Beetle Biology, Ecology and
           Management in the Rocky Mountains: An Addendum to Spruce Beetle in the
           Rockies

    • Authors: Michael Jenkins, Elizabeth Hebertson, A. Munson
      Pages: 21 - 71
      Abstract: Spruce beetle outbreaks have been reported in the Rocky Mountains of western North America since the late 1800s. In their classic paper, Spruce Beetle in the Rockies, Schmid and Frye reviewed the literature that emerged from the extensive outbreaks in Colorado in the 1940s. A new wave of outbreaks has affected Rocky Mountain subalpine spruce-fir forests beginning in the mid-1980s and continuing to the present. These outbreaks have spurred another surge of basic and applied research in the biology, ecology and management of spruce and spruce beetle populations. This paper is a review of literature on spruce beetle focusing on work published since the late 1970s and is intended as an addendum to Spruce Beetle in the Rockies.
      PubDate: 2014-01-03
      DOI: 10.3390/f5010021
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 72-87: Population Dynamics of Lepidoptera Pests in
           Eucalyptus urophylla Plantations in the Brazilian Amazonia

    • Authors: José Zanuncio, Pedro Lemes, Germi Santos, Marcus Soares, Carlos Wilcken, José Serrão
      Pages: 72 - 87
      Abstract: Forestry companies study the population dynamics of insect pests in Integrated Pest Management for cost effectiveness. The objective of this study was to obtain qualitative and quantitative information on population fluctuation of the Lepidopteran defoliators of Eucalyptus urophylla plants in the Brazilian Amazon rainforest. In all, 402 species were collected, of which 10 were primary pests, nine were secondary pests, and the remaining bore no definite relevance to eucalyptus. Primary pests formed a low percentage of the total species, although they recorded a high percentage of the total number of individuals. The abundance of secondary pests, except in Caracuru, was less than 150 specimens annually. Primary pests showed higher population peaks during periods of low precipitation. The small number of species and the high abundance of primary and secondary pests could be due to the availability of food, or a deficiency in natural biological control. This suggests the possibilities of population outbreaks in the eucalyptus plantations. The period of highest occurrence for insect species in these crops must be identified so that suitable strategies can be developed for Integrated Pest Management.
      PubDate: 2014-01-10
      DOI: 10.3390/f5010072
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 88-102: Composition and Elevation of Spruce Forests
           Affect Susceptibility to Bark Beetle Attacks: Implications for Forest
           Management

    • Authors: Massimo Faccoli, Iris Bernardinelli
      Pages: 88 - 102
      Abstract: The spruce bark beetle, Ips typographus (L.) (Coleoptera: Curculionidae, Scolytinae), is one of the most destructive insects infesting spruce forests in Europe. Data concerning infestations of I. typographus occurring over the last 19 years (1994–2012) on the Southern Alps were analyzed in seven spruce forest types: (1) pure spruce plantations; (2) pure spruce reforestations; (3) pure spruce mountain forests; (4) pure spruce alpine forests; (5) spruce-conifer mixed forests; (6) spruce-broadleaf mixed forests; and (7) spruce-conifer-broadleaf mixed forests. The collected data included the amount of I. typographus damage and the location and composition of the infested forests. The results indicate that different forest types are differently susceptible to I. typographus. Plantations, reforestations and mountain spruce forests show mean damage and mean number of infestations higher than other forest types. Within pure spruce forests, alpine forests growing at high elevations (>1300 m) suffer low damage. Furthermore, the mean number of infestation spots recorded annually in the different spruce forest types is negatively correlated with a Naturality Index value. The results suggest that forest composition and elevation are the main factors driving the risk of I. typographus damage. A new management strategy for some spruce forest types is needed, with a progressive reduction of pure spruce forests at low altitude and an increase of broadleaf composition.
      PubDate: 2014-01-14
      DOI: 10.3390/f5010088
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 103-133: Management for Mountain Pine Beetle
           Outbreak Suppression: Does Relevant Science Support Current Policy?

    • Authors: Diana Six, Eric Biber, Elisabeth Long
      Pages: 103 - 133
      Abstract: While the use of timber harvests is generally accepted as an effective approach to controlling bark beetles during outbreaks, in reality there has been a dearth of monitoring to assess outcomes, and failures are often not reported. Additionally, few studies have focused on how these treatments affect forest structure and function over the long term, or our forests’ ability to adapt to climate change. Despite this, there is a widespread belief in the policy arena that timber harvesting is an effective and necessary tool to address beetle infestations. That belief has led to numerous proposals for, and enactment of, significant changes in federal environmental laws to encourage more timber harvests for beetle control. In this review, we use mountain pine beetle as an exemplar to critically evaluate the state of science behind the use of timber harvest treatments for bark beetle suppression during outbreaks. It is our hope that this review will stimulate research to fill important gaps and to help guide the development of policy and management firmly based in science, and thus, more likely to aid in forest conservation, reduce financial waste, and bolster public trust in public agency decision-making and practice.
      PubDate: 2014-01-15
      DOI: 10.3390/f5010103
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 134-152: Spatial Pattern of Populus euphratica
           Forest Change as Affected by Water Conveyance in the Lower Tarim River

    • Authors: Shuhong Peng, Xi Chen, Jing Qian, Shuguang Liu
      Pages: 134 - 152
      Abstract: To restore declining species, including Populus euphratica and other riparian communities, in the river ecosystem of the lower Tarim River, the ecological water conveyance project (EWCP), as a part of an integrated water resource management plan, was implemented in 2000. The EWCP aims to schedule and manage the water resources in the upper reaches and transfer water to the lower reaches by a series of intermittent water deliveries. The delivered water flows along a modified river channel and nourishes riparian communities by river overflow flooding. Since it began, it has caused a fierce debate over the response of riparian vegetation to the water conveyance scheme. This study focuses on the lower Tarim River, where Populus euphratica forests have undergone watering, due to the EWCP. Twelve Landsat sensor images and one IKONOS satellite imagery acquired between 1999 and 2009 were used to monitor the change in Populus euphratica forests. Bi-temporal change detection and temporal trajectory analysis were employed to represent the spatial pattern of the forest change. Field investigations were used to analyze the driving forces behind forest change from the perspectives of anthropogenic activities and natural forces. The results showed that Populus euphratica forest have been declining in area, which implies that ecological risks have been increased during the watering process. However, forests areas have increased in the regions where the water supply is abundant, and vice versa.
      PubDate: 2014-01-17
      DOI: 10.3390/f5010134
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 153-176: Resiliency of an Interior Ponderosa Pine
           Forest to Bark Beetle Infestations Following Fuel-Reduction and
           Forest-Restoration Treatments

    • Authors: Christopher Fettig, Stephen McKelvey
      Pages: 153 - 176
      Abstract: Mechanical thinning and the application of prescribed fire are commonly used to restore fire-adapted forest ecosystems in the Western United States. During a 10-year period, we monitored the effects of fuel-reduction and forest-restoration treatments on levels of tree mortality in an interior ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest in California. Twelve experimental plots, ranging in size from 77–144 ha, were established to create two distinct forest structural types: mid-seral stage (low structural diversity; LoD) and late-seral stage (high structural diversity; HiD). Following harvesting, half of each plot was treated with prescribed fire (B). A total of 16,473 trees (8.7% of all trees) died during the 10-year period. Mortality was primarily attributed to bark beetles (Coleoptera: Curculionidae, Scolytinae) (10,655 trees), specifically fir engraver, Scolytus ventralis LeConte, mountain pine beetle, Dendroctonus ponderosae Hopkins, western pine beetle, D. brevicomis LeConte, pine engraver, Ips pini (Say), and, to a much lesser extent, Jeffrey pine beetle, D. jeffreyi Hopkins. Trees of all ages and size classes were killed, but mortality was concentrated in the smaller-diameter classes (19–29.2 and 29.3–39.3 cm at 1.37 m in height). Most mortality occurred three to five years following prescribed burns. Higher levels of bark beetle-caused tree mortality were observed on LoD + B (8.7%) than LoD (4.2%). The application of these and other results to the   management of interior P. ponderosa forests are discussed, with an emphasis on the maintenance of large trees.
      PubDate: 2014-01-20
      DOI: 10.3390/f5010153
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 177-205: Ecological Variability and Carbon Stock
           Estimates of Mangrove Ecosystems in Northwestern Madagascar

    • Authors: Trevor Jones, Harifidy Ratsimba, Lalao Ravaoarinorotsihoarana, Garth Cripps, Adia Bey
      Pages: 177 - 205
      Abstract: Mangroves are found throughout the tropics, providing critical ecosystem goods and services to coastal communities and supporting rich biodiversity. Despite their value, world-wide, mangroves are being rapidly degraded and deforested. Madagascar contains approximately 2% of the world’s mangroves, >20% of which has been deforested since 1990 from increased extraction for charcoal and timber and conversion to small to large-scale agriculture and aquaculture. Loss is particularly prominent in the northwestern Ambaro and Ambanja bays. Here, we focus on Ambaro and Ambanja bays, presenting dynamics calculated using United States Geological Survey (USGS) national-level mangrove maps and the first localized satellite imagery derived map of dominant land-cover types. The analysis of USGS data indicated a loss of 7659 ha (23.7%) and a gain of 995 ha (3.1%) from 1990–2010. Contemporary mapping results were 93.4% accurate overall (Kappa 0.9), with producer’s and user’s accuracies ≥85%. Classification results allowed partitioning mangroves in to ecologically meaningful, spectrally distinct strata, wherein field measurements facilitated estimating the first total carbon stocks for mangroves in Madagascar. Estimates suggest that higher stature closed-canopy mangroves have average total vegetation carbon values of 146.8 Mg/ha (±10.2) and soil organic carbon of 446.2 (±36.9), supporting a growing body of studies that mangroves are amongst the most carbon-dense tropical forests.
      PubDate: 2014-01-21
      DOI: 10.3390/f5010177
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 206-213: Forests: An International and
           Interdisciplinary Scientific Open Access Journal

    • Authors: Eric Jokela
      Pages: 206 - 213
      Abstract: Forests was established to provide comprehensive coverage on the ecology, conservation and management of forests, with the first issue published in March 2010. As an international and multi-disciplinary journal, Forests has provided a forum for publishing process–based and applied scholarly articles that span the technological, environmental, cultural, economic, and social realm associated with the management, use, conservation, and understanding of forested ecosystems. By all accounts, Forests is well poised toward becoming a premier publication outlet in this diverse field of study. In its short tenure, Forests received its first Impact Factor in 2013 (1.094—Science Citation Index Expanded (SCIE)/Web of Science), which placed it 25th out of 62 Forestry journals. Notably, Forests ranked first among the open access journals in this category.
      PubDate: 2014-01-21
      DOI: 10.3390/f5010206
      Issue No: Vol. 5, No. 1 (2014)
       
  • Forests, Vol. 5, Pages 1-20: Large-Scale Regeneration Patterns of Pinus
           nigra Subsp. salzmannii: Poor Evidence of Increasing Facilitation Across a
           Drought Gradient

    • Authors: Pedro Tíscar, Juan Linares
      Pages: 1 - 20
      Abstract: Tree recruitment is a key process underlying stand dynamics and sustainability in managed forests. Woody plant cover is known to affect the regeneration success of Pinus nigra, suggesting the existence of facilitative plant-plant interactions. The regeneration patterns of this Mediterranean pine were analyzed across its distribution area, using data from 3226 plots of the Spanish National Forest Inventory. We aimed to test the hypothesis that seedlings establishment occurs under higher values of either canopy or shrub cover in the driest populations, as predicted by the stress-gradient hypothesis. Data were analyzed by means of Generalized Linear Models and multivariate methods. Results revealed that regeneration failure occurs on a regional scale, and that regeneration is facilitated by tree canopy cover of 55%–80%. A non-linear pattern of interaction along an aridity gradient was identified, with competition at the wettest site, high facilitation at the mid-dry sites, and low facilitation at the driest site. Evidence suggests that some shrub species may facilitate recruitment in the harsher areas. Collectively, our results reduce the possibilities of adapting forest management to drying climates by the application of alternative silvicultural prescriptions involving canopy cover.
      PubDate: 2013-12-31
      DOI: 10.3390/f5010001
      Issue No: Vol. 5, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 730-750: Ambiguity in Timber Trade Regarding
           Efforts to Combat Illegal Logging: Potential Impacts on Trade between
           South-East Asia and Europe

    • Authors: Alexandru Giurca, Ragnar Jonsson, Francesca Rinaldi, Hari Priyadi
      Pages: 730 - 750
      Abstract: Raised public concern in the European Union (EU) about the legality of its timber imports has pushed the European Commission to raise its standards and legality demands for wood imports. Combining literature reviews, structured interviews and trade data analyses, this study assesses the potential influence from Forest Law Enforcement Governance and Trade (FLEGT) (with its Voluntary Partnership Agreements (VPA) system and new legislation EU Timber Regulation (EUTR)), and third party verification schemes on the timber trade between tropical countries and Europe. These instruments have the potential to reduce the amount of illegally sourced timber being placed on the market, and they seem to have resulted in both increasing support of legality verification and certification uptake. However, there are signs of increased ambiguity in trade that could originate as a side effect of the transition towards a stricter regulation for tropical timber. Such ambiguity is explicitly taken into account here. Possible consequences from increased ambiguity are substitution of oak lumber for tropical hardwood lumber, and a diversion of exports of tropical timber to destinations with a less stringent regulatory framework than the EU. Evidence of these trade patterns in the literature reviews, interviews, and trade data analyses seems to confirm that ambiguity in international trade markets has actually increased since the introduction of these instruments.
      PubDate: 2013-09-25
      DOI: 10.3390/f4040730
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 751-765: Spatial Distribution and Volume of Dead
           Wood in Unmanaged Caspian Beech (Fagus orientalis) Forests from Northern
           Iran

    • Authors: Beitollah Amanzadeh, Khosro Sagheb-Talebi, Bahman Foumani, Farhad Fadaie, Jesús Camarero, Juan Linares
      Pages: 751 - 765
      Abstract: Unmanaged forests are remnants of natural ecosystems that provide a basis for close-to-nature silvicultural research and applications. These forests have high amounts of dead wood, and although this material is being increasingly studied, the diversity of dead wood in terms of different diameters, decay stages, and spatial distribution patterns is as important as its volume for understanding forest dynamics. Here, we study natural forests in northern Iran to investigate the spatial distribution, decay stages, and volume of dead wood in unmanaged temperate forests at different developmental stages. Three stem-mapped sampling plots (100 m × 100 m) were established in uneven-aged stands dominated by Caspian beech (Fagus orientalis Lispsky). The total dead wood ranged from 37 to 119 m2 ha−1. Our results imply a spatial distribution shift from aggregation to randomness for dead trees in Caspian beech forest succession. We detected significant spatial interactions (attraction) between living and dead trees at short to medium spatial scales (1–20 m) in the plot with the earlier successional stage, suggesting that intra-specific competition is a prevailing force causing tree mortality at the stem-exclusion phase. By contrast, as trees become dominant with the mortality of other trees, the random tree-mortality pattern prevails. The spatial distribution and volume of dead wood may serve as a management target in near-to-natural Caspian beech forest. On the basis of our results, conservation-oriented management strategies should take into account the increasing amount of dead wood, particularly of large diameter in a late stage of decay.
      PubDate: 2013-09-26
      DOI: 10.3390/f4040751
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 766-785: Assessing the Potential Stem Growth and
           Quality of Yellow Birch Prior to Restoration: A Case Study in Eastern
           Canada

    • Authors: Louis-Vincent Gagné, Astrid Genet, Aaron Weiskittel, Alexis Achim
      Pages: 766 - 785
      Abstract: Past silvicultural treatments have resulted in the high-grading mixed temperate forests of Québec, Canada. Despite recognition of this issue, the low occurrence of yellow birch (Betula alleghaniensis Britton) within current stands raises questions about the potential of the species to grow and eventually constitute a high-quality forest resource. The objective of this study was to assess this potential using tree characteristics, forest structure and additional site and climatic conditions as predictors. A total of 145 trees were sampled in two areas located in the same bioclimatic zone. Lower-Saguenay-Charlevoix was chosen as an area where a restoration plan could be implemented, whereas Portneuf was selected as a reference. We used nonlinear mixed models to investigate which environmental factors are likely to influence the radial growth and stem quality of yellow birch sample trees. Our results suggest that topographic and climatic conditions, as well as the competitive environment of the trees, are important factors to consider in the evaluation of yellow birch production. Despite the limited occurrence of yellow birch, the potential for growth and quality was high in the Lower-Saguenay-Charlevoix area. For equivalent topographic, climatic, and competitive environment conditions, there was no significant difference in either radial growth or stem quality with Portneuf. We suggest that the economic interest of producing high quality timber should be used to justify the implementation of a restoration strategy in the Lower-Saguenay-Charlevoix area.
      PubDate: 2013-09-30
      DOI: 10.3390/f4040766
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 786-807: Wood Quality and Growth Characterization
           across Intra- and Inter-Specific Hybrid Aspen Clones

    • Authors: James Hart, Francis de Araujo, Barb Thomas, Shawn Mansfield
      Pages: 786 - 807
      Abstract: Trembling aspen (Populus tremuloides Michx.) is one of the most abundant poplar species in North America; it is native, displays substantial breadth in distribution inhabiting several geographical and climatic ecoregions, is notable for its rapid growth, and is ecologically and economically important. As the demand for raw material continues to increase rapidly, there is a pressing need to improve both tree quality and growth rates via breeding efforts. Hybridization is considered one of the most promising options to simultaneously accelerate these tree characteristics, as it takes advantage of heterosis. Two aspen species showing particular promise for hybridization with trembling aspen are European aspen (P. tremula) and Chinese aspen (P. davidiana) because their native climates are similar to that of P. tremuloides and are also very easy to hybridize. In 2003, aspen clones were planted in Athabasca, Alberta from the following species crosses: open pollinated (OP) P. tremuloides (NN), OP P. davidiana (CC), P. tremula × P. tremula (EE), P. tremula × P. tremuloides (EN), and P. tremuloides × P. davidiana (CN). In November 2010, growth measurements and core samples were taken from seven-year field grown clones. Comparisons of the mean growth and cell wall traits were made between crosses using generalized linear model least squares means tests for stem volume, fiber length, fiber width, coarseness, wood density, microfibril angle, total cell wall carbohydrate and lignin content, and lignin composition. The results clearly indicated that the inter-specific crosses offer a means to breed for more desirable wood characteristics than the intra-specific Populus spp. crosses.
      PubDate: 2013-09-30
      DOI: 10.3390/f4040786
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 808-829: Monitoring Post Disturbance Forest
           Regeneration with Hierarchical Object-Based Image Analysis

    • Authors: L. Moskal, Mark Jakubauskas
      Pages: 808 - 829
      Abstract: The main goal of this exploratory project was to quantify seedling density in post fire regeneration sites, with the following objectives: to evaluate the application of second order image texture (SOIT) in image segmentation, and to apply the object-based image analysis (OBIA) approach to develop a hierarchical classification. With the utilization of image texture we successfully developed a methodology to classify hyperspatial (high-spatial) imagery to fine detail level of tree crowns, shadows and understory, while still allowing discrimination between density classes and mature forest versus burn classes. At the most detailed hierarchical Level I classification accuracies reached 78.8%, a Level II stand density classification produced accuracies of 89.1% and the same accuracy was achieved by the coarse general classification at Level III. Our interpretation of these results suggests hyperspatial imagery can be applied to post-fire forest density and regeneration mapping.
      PubDate: 2013-10-11
      DOI: 10.3390/f4040808
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 830-848: Are the Economically Optimal Harvesting
           Strategies of Uneven-Aged Pinus nigra Stands Always Sustainable and
           Stabilizing?

    • Authors: Ignacio López-Torres, Sigfredo Ortuño-Pérez, Fernando García-Robredo, Carmen Fullana-Belda
      Pages: 830 - 848
      Abstract: Traditional uneven-aged forest management seeks a balance between equilibrium stand structure and economic profitability, which often leads to harvesting strategies concentrated in the larger diameter classes. The sustainability (i.e., population persistence over time) and influence of such economically optimal strategies on the equilibrium position of a stand (given by the stable diameter distribution) have not been sufficiently investigated in prior forest literature. This article therefore proposes a discrete optimal control model to analyze the sustainability and stability of the economically optimal harvesting strategies of uneven-aged Pinus nigra stands. For this model, we rely on an objective function that integrates financial data of harvesting operations with a projection matrix model that can describe the population dynamics. The model solution reveals the optimal management schedules for a wide variety of scenarios. To measure the distance between the stable diameter distribution and the economically optimal harvesting strategy distribution, the model uses Keyfitz’s delta, which returns high values for all the scenarios and, thus, suggests that those economically optimal harvesting strategies have an unstabilizing influence on the equilibrium positions. Moreover, the economically optimal harvesting strategies were unsustainable for all the scenarios.
      PubDate: 2013-10-18
      DOI: 10.3390/f4040830
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 849-867: Influence of Different Tillage Systems and
           Weed Treatments in the Establishment Year on the Final Biomass Production
           of Short Rotation Coppice Poplar

    • Authors: Christopher Morhart, Jonathan Sheppard, Frieder Seidl, Heinrich Spiecker
      Pages: 849 - 867
      Abstract: In this study the influence of three different tillage systems in combination with eight varying weed treatments applied within the establishment year and its effect on the final above ground leafless biomass production (after the third growing season) of short rotation coppice poplar is presented. The three tillage systems included variants with ploughing and harrowing, variants with cultivation and ley cropping and variants without tillage. Weed treatments included the application of different herbicides, but also more environmentally sound variants such as mulching and the use of mulch materials to avoid the use of herbicides. To estimate the influence on final biomass production, regression analysis was undertaken using DBH as the predictor variable. Based on 1056 DBH measurements the biomass production of the different variants was compared. The interactions of tillage system and weed treatment on biomass yield were found to be statistically significant. Between tillage systems the ploughing variant displayed a better overall performance than the cultivation with ley crop variant and the variant without any tillage. Differing weed treatments reveal greater success for the whole area application of herbicides than band application, both being better than the use of mulch materials. These results suggest that the right tillage system in combination with effective chemical weed control is the key to the successful establishment of Short rotation coppice (SRC) poplar plantation following the principles of an integrated weed management approach. Furthermore, ecological variants such as ploughing in combination with the use of mulch materials and mechanical vegetation control between the rows could be a solution to reduce dependence on chemical control. However, this comes at the expense of a considerable loss in yield.
      PubDate: 2013-10-24
      DOI: 10.3390/f4040849
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 868-886: Estimation of the Relationship between
           Urban Park Characteristics and Park Cool Island Intensity by Remote
           Sensing Data and Field Measurement

    • Authors: Zhibin Ren, Xingyuan He, Haifeng Zheng, Dan Zhang, Xingyang Yu, Guoqiang Shen, Ruichao Guo
      Pages: 868 - 886
      Abstract: The cooling effects of urban parks, which form “Park Cool Island” (PCI), can help decrease land surface temperature (LST) and mitigate urban heat island (UHI) effects. PCI intensity largely depends on the characteristics of urban parks. The relationship between PCI intensity and urban park characteristics such as urban park size has been well documented. However, it is still unclear how urban forest structures in parks affect PCI intensity and particularly whether the relationship changes across seasons. In this study, PCI intensity for 33 parks in Changchun, China was obtained from Landsat-5 Thematic Mapper (TM) data and then correlated with urban park characteristics such as the size derived from “Systeme Probatoire d’Observation dela Tarre” (SPOT) satellite data and the forest structures of parks derived from the field-based survey to uncover the relationship between urban park characteristics and PCI intensity. Our results suggested that (1) The PCI intensity varied across seasons and the cooling effect of parks in summer was higher than that in autumn. (2) The increase of urban park size was still an effective measure to mitigate UHI. However, urban park size was non-linearly correlated to PCI intensity. (3) Not only by increasing urban park size, but also by optimizing urban park shape and forest structures in parks can increase PCI intensity. (4) The relationship between PCI intensity and urban park characteristics changed across seasons and seasons should be considered when exploring the relationship between them. These findings can deepen the understanding of PCI formation and provide useful information for urban planners about how to design urban parks to maximize their PCI intensity and mitigate UHI effects.
      PubDate: 2013-10-24
      DOI: 10.3390/f4040868
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 887-897: Concentration Levels of Imidacloprid and
           Dinotefuran in Five Tissue Types of Black Walnut, Juglans nigra

    • Authors: Katheryne Nix, Paris Lambdin, Jerome Grant, Carla Coots, Paul Merten
      Pages: 887 - 897
      Abstract: Black walnut, a valuable economic and environmentally important species, is threatened by thousand cankers disease. Systemic imidacloprid and dinotefuran applications were made to mature black walnut trees to evaluate their translocation and concentration levels in various tissue types including leaf, twig, trunk core, nutmeat, and walnut husk. The metabolism of imidacloprid in plants produces a metabolite, olefin-imidacloprid, which has been documented to have insecticidal properties in other systems. Trunk CoreTect (imidacloprid) soil pellets and a trunk spray of dinotefuran were applied to mature black walnuts in spring 2011. Imidacloprid concentrations were detected in both the lower and upper strata in all tissue types tested and progressively increased through month 12 post-treatment in twig and leaf tissue. Olefin-imidacloprid was detected in the nutmeat and walnut husk. Dinotefuran was only detected in the first sampling period and was found in low concentration levels in leaf and twig tissue types, and was not detected in the trunk, nutmeat or the walnut husk.
      PubDate: 2013-11-01
      DOI: 10.3390/f4040887
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 898-921: Applicability of International Harvesting
           Equipment Productivity Studies in Maine, USA: A Literature Review

    • Authors: Patrick Hiesl, Jeffrey Benjamin
      Pages: 898 - 921
      Abstract: Harvesting equipment productivity studies have been conducted in many countries around the world spanning over 25 years. These studies have shown that many factors influence individual machine productivity. These factors include stand and site conditions, equipment configuration, management objectives, and operator experience. Productivity can increase or decrease with slight changes in any of these factors. This literature review also highlights the variety of experimental designs and data collection methods encountered in a cross section of those studies. It further shows the variation in species composition, stand density, tree diameter, and harvest prescription. Although studies that include the influence of operator performance on harvest equipment productivity are limited, they were included in this review where appropriate and available. It is clear that productivity equations should be developed using population-level data with several operators. Some studies were conducted in stands similar to Maine, but they used harvesting equipment that is not commonly used in logging operations in this state. Therefore the applicability of existing studies to the logging industry in Maine, USA, is very limited. Our conclusion is that in order to accurately predict harvesting productivity it is necessary to develop regional harvesting productivity equations using harvesting equipment commonly used in Maine. Forest operations researchers in other regions will be able to use this summary to explore the difficulty of applying productivity information to regional logging operations.
      PubDate: 2013-11-05
      DOI: 10.3390/f4040898
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 922-944: A Photogrammetric Workflow for the
           Creation of a Forest Canopy Height Model from Small Unmanned Aerial System
           Imagery

    • Authors: Jonathan Lisein, Marc Pierrot-Deseilligny, Stéphanie Bonnet, Philippe Lejeune
      Pages: 922 - 944
      Abstract: The recent development of operational small unmanned aerial systems (UASs) opens the door for their extensive use in forest mapping, as both the spatial and temporal resolution of UAS imagery better suit local-scale investigation than traditional remote sensing tools. This article focuses on the use of combined photogrammetry and “Structure from Motion” approaches in order to model the forest canopy surface from low-altitude aerial images. An original workflow, using the open source and free photogrammetric toolbox, MICMAC (acronym for Multi Image Matches for Auto Correlation Methods), was set up to create a digital canopy surface model of deciduous stands. In combination with a co-registered light detection and ranging (LiDAR) digital terrain model, the elevation of vegetation was determined, and the resulting hybrid photo/LiDAR canopy height model was compared to data from a LiDAR canopy height model and from forest inventory data. Linear regressions predicting dominant height and individual height from plot metrics and crown metrics showed that the photogrammetric canopy height model was of good quality for deciduous stands. Although photogrammetric reconstruction significantly smooths the canopy surface, the use of this workflow has the potential to take full advantage of the flexible revisit period of drones in order to refresh the LiDAR canopy height model and to collect dense multitemporal canopy height series.
      PubDate: 2013-11-06
      DOI: 10.3390/f4040922
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 945-967: Nordic Forest Energy Solutions in the
           Republic of Karelia

    • Authors: Yuri Gerasimov, Sergei Senko, Timo Karjalainen
      Pages: 945 - 967
      Abstract: The situation in Karelia, a region in Northwest Russia, is analyzed in the context of forest energy. The annual potential energy available from wood harvesting is about 7 tera watt hours (TWh) (3.6 million m3), which is equal to the total need of Karelia in energy for municipal heating. We point out that the contribution to the municipal economy, the moderate heating cost, the enhanced energy security in the cold Russian climate, the environmental friendliness, the better access to the forests and the utilization of the proven Nordic forest energy solutions (NFES) might have important consequences for strategy-making processes in forest energy development. For this purpose, connecting Analytic Hierarchy Process (AHP) with SWOT (internal strengths (S) or weaknesses (W) and external opportunities (O) or threats (T)) analysis is proposed to identify local operational strategies and assign priorities. Major threats include lack of government support, an insufficient road network, the dominance of extensive forest management, gasification and financial indiscipline. Analysis indicates that NFES are viewed positively for the Russian conditions. The forest biomass market has virtually unlimited opportunities for growth. Together, with the transition to intensive forest management, favorable policy in terms of forestry development programs can support bioenergy development. The advantageous location of existing power plants next to forests, increasing fossil fuel prices, the improvement of the road network and the availability of new technology are seen as potential opportunities for NFES. However, the results also indicate that there is substantial uncertainty and skepticism concerning how such markets benefit forest leaseholders who would like to adopt forest energy. The lack of bioenergy technology development, high transportation cost, low awareness of NFES, high demands for roads, the requirement for skilled specialists and wood fuel quality are the main weaknesses regarding the transfer of NFES to Karelia.
      PubDate: 2013-11-13
      DOI: 10.3390/f4040945
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 968-983: Deforestation and Changes in Landscape
           Patterns from 1979 to 2006 in Suan County, DPR Korea

    • Authors: Choljun Pang, Haiying Yu, Jun He, Jianchu Xu
      Pages: 968 - 983
      Abstract: The Democratic People’s Republic of Korea (DPR Korea) suffered considerable upland deforestation during the 1990s, yet its consequences remain relatively unknown. This paper examines this deforestation and resulting land-use change patterns by analysis of Landsat satellite images from 1979, 1992, 2001 and 2006 in Suan County, Hwanghae Province, DPR Korea. Results show that there has been significant closed canopy forest loss and a dramatic expansion of agricultural land during this period. Most forestlands were converted to farmland during 1992 and 2001. Food shortages, along with fuelwood and timber extraction, are considered to be the main drivers of deforestation. Landscape analysis also showed that closed canopy forests have been severely fragmented and degraded. These research findings make a contribution to an insufficient body of literature on environmental issues in DPR Korea and helps to establish a baseline for monitoring land-use and land-cover changes in the country.
      PubDate: 2013-11-13
      DOI: 10.3390/f4040968
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 984-1002: Above-Ground Biomass and Biomass
           Components Estimation Using LiDAR Data in a Coniferous Forest

    • Authors: Qisheng He, Erxue Chen, Ru An, Yong Li
      Pages: 984 - 1002
      Abstract: This study aims to estimate forest above-ground biomass and biomass components in a stand of Picea crassifolia (a coniferous tree) located on Qilian Mountain, western China via low density small-footprint airborne LiDAR data. LiDAR points were first classified into ground points and vegetation points. After, vegetation statistics, including height quantiles, mean height, and fractional cover were calculated. Stepwise multiple regression models were used to develop equations that relate the vegetation statistics from field inventory data with field-based estimates of biomass for each sample plot. The results showed that stem, branch, and above-ground biomass may be estimated with relatively higher accuracies; estimates have adjusted R2 values of 0.748, 0.749, and 0.727, respectively, root mean squared error (RMSE) values of 9.876, 1.520, and 15.237 Mg·ha−1, respectively, and relative RMSE values of 12.783%, 12.423%, and 14.163%, respectively. Moreover, fruit and crown biomass may be estimated with relatively high accuracies; estimates have adjusted R2 values of 0.578 and 0.648, respectively, RMSE values of 1.022 and 5.963 Mg·ha−1, respectively, and relative RMSE values of 23.273% and 19.665%, respectively. In contrast, foliage biomass estimates have relatively low accuracies; they had an adjusted R2 value of 0.356, an RMSE of 3.691 Mg·ha−1, and a relative RMSE of 26.953%. Finally, above-ground biomass and biomass component spatial maps were established using stepwise multiple regression equations. These maps are very useful for updating and modifying forest base maps and registries.
      PubDate: 2013-11-20
      DOI: 10.3390/f4040984
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1003-1031: Allometries for Widely Spaced Populus
           ssp. and Betula ssp. in Nurse Crop Systems

    • Authors: Hendrik Stark, Arne Nothdurft, Jürgen Bauhus
      Pages: 1003 - 1031
      Abstract: Nurse crops of widely spaced pioneer trees are a silvicultural approach to protect the regeneration of frost sensitive target tree species. If overstorey nurse crops are harvested, they can provide additional short-term benefits through increased biomass production, e.g., for bioenergy. However, the intensification of biomass exports from forests might impact negatively on ecosystem nutrient pools. Thus, precise allometric biomass equations are required to quantify biomass and nutrient removals. Since an analysis of published allometric equations developed for typical, dense aspen or birch forests showed that the tree height-to-diameter ratio correlated positively and the proportion of branch biomass negatively with stand density, we developed new allometric biomass equations for widely spaced aspen and birch growing at 4 x 4 m spacing. These equations yielded a root mean squared error of 13% when predicting total aboveground woody biomass for our sample trees. In contrast, the corresponding root mean squared error produced by allometric biomass equations from the literature ranged between 17% to 106% of actual dry biomass. Our results show that specific allometric biomass equations are needed for widely spaced pioneer trees both for accurate estimates of biomass and the nutrients contained within.
      PubDate: 2013-11-22
      DOI: 10.3390/f4041003
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1032-1054: Potential for Climate Change Mitigation
           in Degraded Forests: A Study from La Primavera, México

    • Authors: Arturo Balderas Torres, Ricardo Ontiveros Enríquez, Margaret Skutsch, Jon Lovett
      Pages: 1032 - 1054
      Abstract: Forests contribute to climate change mitigation by removing atmospheric carbon dioxide and storing it in biomass and other carbon pools. Additionally, since appropriate forest management can reduce emissions from deforestation and forest degradation, it is important to estimate the magnitude of these services to include them into climate policy. We used a forest inventory stratified by canopy cover in the oak-pine forest of La Primavera Biosphere Reserve in México (30,500 ha), to assess the potential provision of forest carbon services. Inventory results were used in combination with a Landsat image to estimate carbon stocks in arboreal biomass. Potential carbon removals were calculated from published allometric equations and models estimating tree growth rates, for enhancements in forested areas and for reforestation/afforestation. Carbon stocks estimated in arboreal biomass at the time of the inventory were 4.16 MtCO2eq (3.42–4.89). The potential for further carbon sequestration and enhancement could take the level of stocks up to 9.77 MtCO2eq (7.66–11.89, 95% confidence interval); previous fires have degraded carbon stocks below their natural potential. The results present a gradient of carbon stocks for different degradation levels and are consistent with national and international estimates and previous local research. The baseline for the estimation of reduced emissions is critical for assessing the overall contribution of forests to mitigate climate change. The local baseline of emissions might be around 1% according to historical data; however, when enhancements and reduced emissions are valuated together, a baseline of 3.7% is required to prevent the creation of perverse incentives favouring previously degraded areas; considering these figures for reduced emissions, the yearly carbon services provided by La Primavera, including enhancements, sequestration and reduced emissions, could be between 169.4 ktCO2eq/year (134.8–204.5) and 282.1 ktCO2eq/year (228.2–337.1), respectively. Over a period of 60 years, this would be equivalent to 2.4 and 4.1 times the magnitude of mean standing stocks at the time of the inventory. If incentive-based mechanisms are used to maintain and enhance forest carbon services and perverse incentives are to be avoided, a balanced mix of incentives and controls is needed.
      PubDate: 2013-11-22
      DOI: 10.3390/f4041032
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1055-1086: Late-Successional and Old-Growth Forests
           in the Northeastern United States: Structure, Dynamics, and Prospects for
           Restoration

    • Authors: Mark Ducey, John Gunn, Andrew Whitman
      Pages: 1055 - 1086
      Abstract: Restoration of old-growth forest structure is an emerging silvicultural goal, especially in those regions where old-growth abundance falls below the historic range of variability. However, longitudinal studies of old-growth dynamics that can inform silvicultural and policy options are few. We analyzed the change in structure, including stand density, diameter distribution, and the abundance of large live, standing dead, and downed dead trees on 58 late-successional and old-growth plots in Maine, USA, and compared these to regional data from the U.S. Forest Inventory and Analysis program. Structural dynamics on the late-successional plots reflected orderly change associated with density-dependent growth and mortality, but dynamics on the old-growth plots were more variable. Some plots experienced heavy mortality associated with beech bark disease. Diameter distributions conformed poorly to a classic exponential distribution, and did not converge toward such a distribution at the plot scale. Although large live trees showed a broad trend of increasing density in regional forests, recent harvesting patterns offset a considerable fraction of those gains, while mean diameter was static and the number of large dead trees was weakly declining. Even though forests of the northeast are aging, changes in silviculture and forest policy are necessary to accelerate restoration of old-growth structure.
      PubDate: 2013-11-26
      DOI: 10.3390/f4041055
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1087-1105: Forest Typification to Characterize the
           Structure and Composition of Old-growth Evergreen Forests on Chiloe
           Island, North Patagonia (Chile)

    • Authors: Jan Bannister, Pablo Donoso
      Pages: 1087 - 1105
      Abstract: The Evergreen forest type develops along the Valdivian and North-Patagonian phytogeographical regions of the south-central part of Chile (38° S–46° S). These evergreen forests have been scarcely studied south of 43° S, where there is still a large area made up of old-growth forests. Silvicultural proposals for the Evergreen forest type have been based on northern Evergreen forests, so that the characterization of the structure and composition of southern Evergreen forests, e.g., their typification, would aid in the development of appropriate silvicultural proposals for these forests. Based on the tree composition of 46 sampled plots in old-growth forests in an area of >1000 ha in southern Chiloé Island (43° S), we used multivariate analyses to define forest groups and to compare these forests with other evergreen forests throughout the Archipelago of North-Patagonia. We determined that evergreen forests of southern Chiloé correspond to the North-Patagonian temperate rainforests that are characterized by few tree species of different shade tolerance growing on fragile soils. We discuss the convenience of developing continuous cover forest management for these forests, rather than selective cuts or even-aged management that is proposed in the current legislation. This study is a contribution to forest classification for both ecologically- and forestry-oriented purposes.
      PubDate: 2013-11-28
      DOI: 10.3390/f4041087
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1106-1120: Contrasting Hydraulic Strategies during
           Dry Soil Conditions in Quercus rubra and Acer rubrum in a Sandy Site in
           Michigan

    • Authors: Julia Thomsen, Gil Bohrer, Ashley Matheny, Valeriy Ivanov, Lingli He, Heidi Renninger, Karina Schäfer
      Pages: 1106 - 1120
      Abstract: Correlation analyses were carried out for the dynamics of leaf water potential in two broad-leaf deciduous tree species in a sandy site under a range of air vapor pressure deficits and a relatively dry range of soil conditions. During nights when the soil is dry, the diffuse-porous, isohydric and shallow-rooted Acer rubrum does not recharge its xylem and leaf water storage to the same capacity that is observed during nights when the soil is moist. The ring-porous, deep-rooted Quercus rubra displays a more anisohydric behavior and appears to be capable of recharging to capacity at night-time even when soil moisture at the top 1 m is near wilting point, probably by accessing deeper soil layers than A. rubrum. Compared to A. rubrum, Q. rubra displays only a minimal level of down-regulation of stomatal conductance, which leads to a reduction of leaf water potential during times when vapor pressure deficit is high and soil moisture is limiting. We determine that the two species, despite typically being categorized by ecosystem models under the same plant functional type—mid-successional, temperate broadleaf—display different hydraulic strategies. These differences may lead to large differences between the species in water relations, transpiration and productivity under different precipitation and humidity regimes.
      PubDate: 2013-12-11
      DOI: 10.3390/f4041106
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1121-1140: Use of Forest Residues for Building
           Forest Biomass Supply Chains: Technical and Economic Analysis of the
           Production Process

    • Authors: Mario Cozzi, Francesco Di Napoli, Mauro Viccaro, Severino Romano
      Pages: 1121 - 1140
      Abstract: In the field of biomass and bio-energy production, an analysis was performed of the whole production process from biomass supply to bio-energy production. The available biomass, harvesting and transportation costs and the distribution of supply area were quantified. The assessment of volumes was based on forest type and its relative increment. The transportation costs, influenced by different species-specific and site-specific factors, were calculated by integrating data in a geographic information system (GIS). The economic values calculated were the main economic indicators (net present value (NPV), internal rate of return (IRR) and Payback Period). The results show that: (a) there is a good supply of forest biomass across most of the territory of Basilicata region, Italy; (b) the harvesting and transportation costs are dependent on biomass density and distances; (c) there are strong margins for economic profits at the level of each single supply basin; and (d) the endogenous value added was estimated to about 150 seasonal workers.
      PubDate: 2013-12-11
      DOI: 10.3390/f4041121
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1141-1157: White Spruce Plantations on Abandoned
           Agricultural Land: Are They More Effective as C Sinks than Natural
           Succession?

    • Authors: Sylvie Tremblay, Rock Ouimet
      Pages: 1141 - 1157
      Abstract: The objective of this study was to compare organic carbon (C) accumulation in plantations (PL) and natural succession (NS) established on fallow lands along a 50-year chronosequence in the eastern mixed forest subzone of Quebec (Canada). Above- and below-ground woody biomass were estimated from vegetation measurement surveys, and litter and soil (0–50 cm depth) C from samplings. At the year of abandonment, total C content of both PL and NS sites averaged 100 ± 13 Mg C ha−1. Over 50 years, total C content doubled on NS sites and tripled on PL sites (217.9 ± 28.7 vs. 285.7 ± 31.0 Mg ha−1) with respect to fallow land. On NS sites, the new C stocks accumulated entirely in the vegetation. On PL sites, C accumulated mostly in the vegetation and to a lesser extent in the litter, whereas it decreased by a third in the soil. As a result, the net C accumulation rate was 1.7 ± 0.7 Mg ha−1 yr−1 greater on PL sites than on NS sites over 50 years. By the 23rd year, PL sites became greater net C sinks than NS sites in the fallow lands of the study area, even with the loss of soil C.
      PubDate: 2013-12-11
      DOI: 10.3390/f4041141
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1158-1170: Risks, Information and Short-Run Timber
           Supply

    • Authors: Francesca Rinaldi, Ragnar Jonsson
      Pages: 1158 - 1170
      Abstract: Efforts to increase wood mobilization have highlighted the need to appraise drivers of short-run timber supply. The current study aims to shed further light on harvesting decisions of private forest owners, by investigating optimal harvesting under uncertainty, when timber revenues are invested on financial markets and uncertainty is mitigated by news releases. By distinguishing between aggregate economic risk and sector specific risks, the model studies in great detail optimal harvesting-investment decisions, with particular emphasis on the non-trivial transmission of risk on optimal harvesting, and on the way private forest owners react to news and information. The analysis of the role played by information in harvesting decisions is a novelty in forest economic theory. The presented model is highly relevant from a policy—information is a commonly used forest policy instrument—as well as a practical perspective, since the mechanism of risk transmission is at the basis of timber pricing.
      PubDate: 2013-12-11
      DOI: 10.3390/f4041158
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1171-1198: The Impact of Industrial Context on
           Procurement, Management and Development of Harvesting Services: A
           Comparison of Two Swedish Forest Owners Associations

    • Authors: Emanuel Erlandsson
      Pages: 1171 - 1198
      Abstract: Increasing demands to harvesting production and quality require improved management practices. This study’s purpose was to analyze the impact of industrial context on procurement, management, and development of harvesting services. Using interviews, functions were modeled at two forest owners associations (FOAs) with outsourced harvesting services. One FOA had its own sawmills, requiring frequent harvesting production adjustments to meet varying volume demand in the short-term. The long-term uncertainty was however low because of good visibility of future demand (>6 months). The other FOA did not own mills and produced wood according to fixed six-month delivery contracts. This meant few short-term production adjustments, but long-term uncertainty due to low visibility of future demand. Demand uncertainty resulted in corresponding needs for harvesting capacity flexibility. This could have been met by a corresponding proportion of short-term contracts for capacity. In this study, however, a large proportion (>90%) of long-term contracts was found, motivated by a perceived contractor shortage. It was also noted that although contractor investment cycles (4–6 years) matched the FOAs’ strategic horizons (3–5 years), contractors’ investment plans were not considered in the FOAs’ strategic planning. The study concludes with a characterization of different FOA contexts and their corresponding needs for capacity flexibility.
      PubDate: 2013-12-11
      DOI: 10.3390/f4041171
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1199-1219: An Exploratory Assessment of a
           Smartphone Application for Public Participation in Forest Fuels
           Measurement in the Wildland-Urban Interface

    • Authors: Colin Ferster, Nicholas Coops, Howard Harshaw, Robert Kozak, Michael Meitner
      Pages: 1199 - 1219
      Abstract: Wildfire management in the wildland-urban interface (WUI) protects property and life from wildland fire. One approach that has potential to provide information about the amount and location of fuels to forest managers and, at the same time, increase public knowledge and engagement in reducing wildfire threats is public participation in scientific research (PPSR)—also known as citizen science—where members of the public participate in the research process. In this exploratory study, residents of a wildfire-affected community tested a smartphone application to collect data about forest fuels and answered questions about wildfire, their community, and experiences using the application. In this paper, the application is introduced, the volunteers’ motivations, attitudes, and behaviors are considered, and the potential of using a PPSR approach for wildfire management discussed. Although there are practical challenges to applying PPSR approaches to wildfire hazard management, the participants in this study demonstrated the potential of PPSR to increase awareness and understanding of actions that can reduce the threat of wildfire. Wildfire managers may consider utilizing PPSR approaches to engage the community in wildfire preparedness.
      PubDate: 2013-12-16
      DOI: 10.3390/f4041199
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 1220-1231: Potentials for Mutually Beneficial
           Collaboration Between FIA Specialists and IEG-40 Pathologists and
           Geneticists Working on Fusiform Rust

    • Authors: Ellis Cowling, KaDonna Randolph
      Pages: 1220 - 1231
      Abstract: The purpose of this article is to encourage development of an enduring mutually beneficial collaboration between data and information analysts in the US Forest Service’s “Enhanced Forest Inventory and Analysis (FIA) Program” and forest pathologists and geneticists in the information exchange group (IEG) titled “Genetics and Breeding of Southern Forest Trees.” The goal of this collaborative partnership is to take full advantage of the Forest Health Monitoring capabilities within the Enhanced FIA Program to provide up-to-date information on the incidence of fusiform rust on loblolly and slash pine stands in the Southern United States and to periodically report the status of the rust epidemic in this region. Our initial analysis of 2000–2011 FIA data demonstrates that careful analysis and interpretation of results from continuing FIA observations can provide valuable guidance for optimizing the performance of forest tree improvement programs in this region.
      PubDate: 2013-12-17
      DOI: 10.3390/f4041220
      Issue No: Vol. 4, No. 4 (2013)
       
  • Forests, Vol. 4, Pages 666-692: Narrative History of the Resistance
           Screening Center: It’s Origins, Leadership and Partial List of
           Public Benefits and Scientific Contributions

    • Authors: Ellis Cowling, Carol Young
      Pages: 666 - 692
      Abstract: Forty years ago, the US Department of Agriculture (USDA) Forest Service developed and currently operates the Resistance Screening Center near Asheville, North Carolina, as a service to both industry and university-based tree improvement programs and tree-seed exporting companies in the southern US, Mexico, and Central America. Seed lots from more than 15,000 selections of slash and loblolly pines have been evaluated for genetically-controlled resistance to fusiform rust and other diseases including pitch canker, dogwood anthracnose, and brown spot needle blight. The screening system uses a greenhouse-based artificial inoculation system with controlled density of inoculum from geographically diverse sources of the rust pathogen. Results are completed in 6–9 months and are reasonably well-correlated with field-based progeny tests. Operating costs of the Center are shared by both the USDA Forest Service and its clients. The technologically sophisticated methods and professional skills of the Center staff have been applied to facilitate and accelerate progress in region-wide timber production, scientific understanding of the fusiform rust pathosystem, and graduate education of forest geneticists and pathologists in universities.
      PubDate: 2013-08-22
      DOI: 10.3390/f4030666
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 693-709: How to Influence Forest-Related Issues in
           the European Union? Preferred Strategies among Swedish Forest Industry
           

    • Authors: Therese Bjärstig, E. Keskitalo
      Pages: 693 - 709
      Abstract: Although forestry is not a regulated area in the European Union (EU), numerous decisions in other policy areas are related to forestry. However, its position outside of formal policy-making can result in the fact that actors, such as those within the forest industry, may have a larger role when compared to other policy sectors where the state system has an integrated role. This explorative study reviews the ways in which the forest industry in Sweden, one of the EU states with the most forest land, tries to protect and promote its interests on an EU-level. It concludes that a main way to influence decision-making in the EU is through lobbying, through its own organisations and through the transnational trade association, The Confederation of European Paper Industries (CEPI). The study shows that collectively conducted lobbying is largely preferred which means that internal communication is important since lobbying at the EU-level is potentially limited by the diverging positions of trade association members as well as among the different trade associations themselves.
      PubDate: 2013-08-28
      DOI: 10.3390/f4030693
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 710-729: Indicators and Determinants of Small-Scale
           Bamboo Commercialization in Ethiopia

    • Authors: Tefera Endalamaw, André Lindner, Jürgen Pretzsch
      Pages: 710 - 729
      Abstract: Bamboo is an abundant resource in Ethiopia and has a great potential for commercialization, which can drive rural development. In view of these realities, this study analyzed the state and determinants of small-scale bamboo commercialization in Ethiopia. Data were collected from three major bamboo-growing districts (Awi, Sidama, and Sheka) and four urban centers (Masha, Hawassa, Bahir Dar, and Addis Ababa) via semi-structured interviews, group discussions, and questionnaire surveys with key actors along the value chain. Results revealed distinctive differences in proportion of cash income, value chain structure, and management engagement among the districts. Percentages of cash income were 60.15, 42.60, and 9.48 at Awi, Sidam, and Sheka, respectively. Differences were statistically significant between Sheka and both other districts (p = 0.05), but not between Awi and Sidama. The value chain structure showed that compared with Sheka, Awi and Sidama have a relatively large number of actors involved. The major factors explaining commercialization differences among regions were distance to market and presence of alternative forest products. Within Sheka, households with larger family size, higher education attainment, and access to training reportedly engaged more in commercial extraction. Therefore, we conclude that development of infrastructure for linking resource and consumer centers and expansion of extension education among producers may enhance the commercial engagement of producers and improve the accessibility of bamboo resources for commercial production.
      PubDate: 2013-09-18
      DOI: 10.3390/f4030710
      Issue No: Vol. 4, No. 3 (2013)
       
 
 
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