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  Subjects -> FORESTS AND FORESTRY (Total: 96 journals)
Acta Silvatica et Lignaria Hungarica     Open Access  
Advance in Forestry Research     Open Access   (2 followers)
Advances in Forestry Letters     Open Access   (1 follower)
African Journal of Sustainable Development     Full-text available via subscription   (2 followers)
Agrociencia     Open Access   (2 followers)
Agroforestry Systems     Hybrid Journal   (13 followers)
Annals of Forest Science     Hybrid Journal   (3 followers)
Appita Journal: Journal of the Technical Association of the Australian and New Zealand Pulp and Paper Industry     Full-text available via subscription   (4 followers)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (5 followers)
Arboriculture and Urban Forestry     Free   (7 followers)
Australian Forest Grower     Full-text available via subscription   (2 followers)
Australian Forestry     Full-text available via subscription   (4 followers)
Banko Janakari     Open Access  
Boletin de la Sociedad Argentina de Botanica     Open Access   (1 follower)
Bosque     Open Access   (1 follower)
Canadian Journal of Forest Research     Full-text available via subscription   (47 followers)
Canadian Journal of Plant Science     Full-text available via subscription   (10 followers)
Ciência Florestal     Open Access   (2 followers)
Ciencia forestal en México     Open Access   (1 follower)
Colombia Forestal     Open Access  
Dissertationes Forestales     Open Access  
European Journal of Forest Research     Hybrid Journal   (3 followers)
European Journal of Wood and Wood Products     Hybrid Journal   (3 followers)
Expert Opinion on Environmental Biology     Partially Free  
Floresta e Ambiente     Open Access   (1 follower)
Forest Ecology and Management     Hybrid Journal   (26 followers)
Forest Pathology     Hybrid Journal   (1 follower)
Forest Phytophthoras     Open Access   (1 follower)
Forest Policy and Economics     Hybrid Journal   (16 followers)
Forest Research Papers     Open Access   (2 followers)
Forest Science     Full-text available via subscription   (4 followers)
Forest Science and Practice     Hybrid Journal   (4 followers)
Forest Science and Technology     Partially Free   (1 follower)
Forest Systems     Open Access  
Foresta Veracruzana     Open Access   (2 followers)
Forestry Chronicle     Full-text available via subscription   (8 followers)
Forestry Studies : Metsanduslikud Uurimused     Open Access   (2 followers)
Forestry: An International Journal of Forest Research     Hybrid Journal   (10 followers)
Forests     Open Access   (3 followers)
Forests, Trees and Livelihoods     Partially Free   (3 followers)
Ghana Journal of Forestry     Full-text available via subscription  
Holzforschung     Full-text available via subscription  
iForest : Biogeosciences and Forestry     Open Access   (2 followers)
INNOTEC : Revista del Laboratorio Tecnológico del Uruguay     Open Access  
International Forestry Review     Full-text available via subscription   (6 followers)
International Journal of Forest Engineering     Hybrid Journal  
International Journal of Forest, Soil and Erosion     Open Access   (3 followers)
International Journal of Forestry Research     Open Access   (5 followers)
International Wood Products Journal     Hybrid Journal  
ISRN Forestry     Open Access   (1 follower)
Journal of Agriculture, Forestry and the Social Sciences     Full-text available via subscription  
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   (6 followers)
Journal of Forest Products and Industries     Open Access  
Journal of Forest Research     Hybrid Journal   (3 followers)
Journal of Forestry     Full-text available via subscription   (5 followers)
Journal of Forestry Research     Hybrid Journal   (4 followers)
Journal of Horticulture and Forestry     Open Access  
Journal of Natural Resources Policy Research     Hybrid Journal   (12 followers)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Sustainable Forestry     Hybrid Journal   (7 followers)
Journal of The Indian Academy of Wood Science     Hybrid Journal   (2 followers)
Journal of Tropical Forestry and Environment     Open Access  
Journal of Wood Chemistry and Technology     Hybrid Journal   (7 followers)
Journal of Wood Science     Hybrid Journal   (3 followers)
Jurnal Manajemen Hutan Tropika     Open Access   (1 follower)
La Calera     Open Access  
Landscapes     Hybrid Journal   (17 followers)
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   (7 followers)
New Forests     Hybrid Journal   (2 followers)
New Zealand Journal of Forestry Science     Open Access   (1 follower)
Open Journal of Forestry     Open Access   (2 followers)
Pesquisa Florestal Brasileira     Open Access   (1 follower)
Plant Science Bulletin     Free   (7 followers)
Quebracho. Revista de Ciencias Forestales     Open Access   (1 follower)
Research Journal of Forestry     Open Access   (4 followers)
Revista Árvore     Open Access   (2 followers)
Revista Chapingo. Serie Ciencias Forestales y del Ambiente     Open Access   (2 followers)
Revista Verde de Agroecologia e Desenvolvimento Sustentável     Open Access   (3 followers)
Revue forestière française     Full-text available via subscription   (3 followers)
Rwanda Journal     Full-text available via subscription  
Scandinavian Journal of Forest Research     Hybrid Journal   (2 followers)
Science, Technology and Arts Research Journal     Open Access  
Small-scale Forestry     Hybrid Journal   (2 followers)
Southern African Forestry Journal     Full-text available via subscription   (2 followers)
Southern Forests: a Journal of Forest Science     Hybrid Journal   (4 followers)
Tanzania Journal of Forestry and Nature Conservation     Full-text available via subscription  
Trees     Hybrid Journal   (5 followers)
Urban Forestry & Urban Greening     Hybrid Journal   (6 followers)
Veld & Flora     Full-text available via subscription   (2 followers)
Wood and Fiber Science     Full-text available via subscription   (3 followers)
Wood Material Science and Engineering     Hybrid Journal   (4 followers)
Wood Science and Technology     Hybrid Journal   (2 followers)
Forests    [5 followers]  Follow    
  This is an Open Access Journal Open Access journal
     ISSN (Print) 1999-4907
     Published by MDPI Homepage  [119 journals]   [SJR: 0.439]   [H-I: 5]
  • 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 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 518-536: The Utility of Image-Based Point Clouds
           for Forest Inventory: A Comparison with Airborne Laser Scanning
    • Authors: Joanne White, Michael Wulder, Mikko Vastaranta, Nicholas Coops, Doug Pitt, Murray Woods
      Pages: 518 - 536
      Abstract: Airborne Laser Scanning (ALS), also known as Light Detection and Ranging (LiDAR) enables an accurate three-dimensional characterization of vertical forest structure. ALS has proven to be an information-rich asset for forest managers, enabling the generation of highly detailed bare earth digital elevation models (DEMs) as well as estimation of a range of forest inventory attributes (including height, basal area, and volume). Recently, there has been increasing interest in the advanced processing of high spatial resolution digital airborne imagery to generate image-based point clouds, from which vertical information with similarities to ALS can be produced. Digital airborne imagery is typically less costly to acquire than ALS, is well understood by inventory practitioners, and in addition to enabling the derivation of height information, allows for visual interpretation of attributes that are currently problematic to estimate from ALS (such as species, health status, and maturity). At present, there are two limiting factors associated with the use of image-based point clouds. First, a DEM is required to normalize the image-based point cloud heights to aboveground heights; however DEMs with sufficient spatial resolution and vertical accuracy, particularly in forested areas, are usually only available from ALS data. The use of image-based point clouds may therefore be limited to those forest areas that already have an ALS-derived DEM. Second, image-based point clouds primarily characterize the outer envelope of the forest canopy, whereas ALS pulses penetrate the canopy and provide information on sub-canopy forest structure. The impact of these limiting factors on the estimation of forest inventory attributes has not been extensively researched and is not yet well understood. In this paper, we review the key similarities and differences between ALS data and image-based point clouds, summarize the results of current research related to the comparative use of these data for forest inventory attribute estimation, and highlight some outstanding research questions that should be addressed before any definitive recommendation can be made regarding the use of image-based point clouds for this application.
      PubDate: 2013-06-26
      DOI: 10.3390/f4030518
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 537-552: Canopy Structural Changes Following
           Widespread Mortality of Canopy Dominant Trees
    • Authors: Brady Hardiman, Gil Bohrer, Christopher Gough, Peter Curtis
      Pages: 537 - 552
      Abstract: Canopy structure affects forest function by determining light availability and distribution. Many forests throughout the upper Great Lakes region are dominated by mature, even-aged, early successional aspen and birch, which comprise 35%–40% of canopy leaf area, and which are senescing at accelerating rates. In 2008 at the University of Michigan Biological Station, we initiated the Forest Accelerated Succession ExperimenT (FASET) by stem girdling all aspen and birch in replicated stands to induce mortality. Our objective was to understand type and rate of canopy structural changes imposed by rapid but diffuse disturbance consisting of mortality of a single age-species cohort. We characterized changes in canopy structural features in 2008–2011 using ground-based Portable Canopy Lidar (PCL) in paired treated and control stands. As aspen and birch in treated plots died, gap fraction of the upper canopy increased, average leaf height decreased, total canopy height declined, and openness of the whole-canopy increased. All of these trends became more pronounced with time. Our findings suggest that as forests throughout the region pass through the impending successional transition prompted by widespread mortality of canopy-dominant early successional aspen and birch species, the canopy will undergo significant structural reorganization with consequences for forest carbon assimilation.
      PubDate: 2013-07-08
      DOI: 10.3390/f4030537
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 553-574: Strategy Pattern Creation in Forest
           Planning in Swedish Forest-Owning Companies
    • Authors: Malin Nilsson, Ljusk Eriksson, Dianne Wästerlund
      Pages: 553 - 574
      Abstract: Forest-owning companies in Sweden have both a goal to yield a good short-term rate of return on their forest and a goal to maintain a high long-term rate of return by maintaining the production of wood-based products. Both these objectives are taken into account in the forest planning process. For the long-term goal, the companies develop strategies formulated in the forest planning system and for the short-term goal, sale strategies are formulated in the sale plans. These strategies may raise conflicts on how to use the forest resources. These conflicts would occur in the work with the tract bank (TB), the register of stands ready for harvesting. The objective of this study was to analyze how Swedish forest owning companies form their strategy patterns around the work with the TB and to discuss the implications of the pattern formation for forest planning in the companies. Planners and harvest managers at three large forest-owning companies responded to a questionnaire. The results show that the delivery plan based on the sale strategy is often a main factor in determining the content of the TB.
      PubDate: 2013-07-10
      DOI: 10.3390/f4030553
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 575-594: Genetic Improvement of White Spruce
           Mechanical Wood Traits—Early Screening by Means of Acoustic Velocity
           
    • Authors: Patrick Lenz, David Auty, Alexis Achim, Jean Beaulieu, John Mackay
      Pages: 575 - 594
      Abstract: There is a growing interest to use acoustic sensors for selection in tree breeding to ensure high wood quality of future plantations. In this study, we assessed acoustic velocity as a selection trait for the improvement of mechanical wood properties in two 15- and 32-year-old white spruce (Picea glauca [Moench.] Voss) genetic tests. Individual heritability of acoustic velocity was moderate and of the same magnitude as heritability of wood density. Considerable genetic gain could be expected for acoustic velocity and a measure combining velocity and wood density. The relationship between acoustic velocity and cellulose microfibril angle (MFA) was strong on the genetic level and selection based on velocity could effectively improve MFA, which is one of the most important determinants of wood mechanical properties. Although low, the positive relationship between acoustic velocity and tree height presents an interesting opportunity for the improvement of both tree growth and wood quality. On the phenotypic level, MFA was more strongly correlated to acoustic velocity in mature trees than in young trees. The addition of easily obtainable traits such as diameter at breast height (DBH), height-to-diameter ratio as well as wood density to velocity determinations could improve models of MFA at the young and the mature age. We conclude that juvenile acoustic velocity is an appropriate trait to select for wood quality in a tree breeding context.
      PubDate: 2013-07-10
      DOI: 10.3390/f4030575
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 595-612: Foliage and Litter Chemistry,
           Decomposition, and Nutrient Release in Pinus taeda
    • Authors: L. Kiser, Thomas Fox, Colleen Carlson
      Pages: 595 - 612
      Abstract: Following fertilization of forest plantations, high accumulations of nutrients in the forest floor creates the need to assess rates of forest floor decomposition and nutrient release. The study site was a 25-year old experimental loblolly pine plantation in the North Carolina Sandhills Region. Soluble and insoluble N, P, carbohydrate and phenol-tannin fractions were determined in foliage and litter by extraction with trichloroacetic acid. The long-term forest floor decomposition rate and decomposition and nutrient release in an experiment simulating removal of the overstory canopy were also determined. In litter, insoluble protein-N comprised 80%–90% of total-N concentration while soluble inorganic- and organic-P comprised 50%–75% of total-P concentration explaining forest floor N accumulations. Fertilization did not increase soluble carbohydrates in litter and forest floor decomposition rates. Loblolly pine forest floor decomposing in environmental conditions simulating removal of the overstory canopy was greatly accelerated and indicated 75% mass loss and release of 80% of the N pool within one year. This could result in a loss of substantial quantities of N at harvest due to low N uptake by seedlings in the newly planted next rotation suggesting management of the forest floor at harvest is essential to conserve site N capital in these N limited systems.
      PubDate: 2013-07-17
      DOI: 10.3390/f4030595
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 613-631: Managing Understory Vegetation for
           Maintaining Productivity in Black Spruce Forests: A Synthesis within a
           Multi-Scale Research Model
    • Authors: Nelson Thiffault, Nicole Fenton, Alison Munson, François Hébert, Richard Fournier, Osvaldo Valeria, Robert Bradley, Yves Bergeron, Pierre Grondin, David Paré, Gilles Joanisse
      Pages: 613 - 631
      Abstract: Sustainable management of boreal ecosystems involves the establishment of vigorous tree regeneration after harvest. However, two groups of understory plants influence regeneration success in eastern boreal Canada. Ericaceous shrubs are recognized to rapidly dominate susceptible boreal sites after harvest. Such dominance reduces recruitment and causes stagnant conifer growth, lasting decades on some sites. Additionally, peat accumulation due to Sphagnum growth after harvest forces the roots of regenerating conifers out of the relatively nutrient rich and warm mineral soil into the relatively nutrient poor and cool organic layer, with drastic effects on growth. Shifts from once productive black spruce forests to ericaceous heaths or paludified forests affect forest productivity and biodiversity. Under natural disturbance dynamics, fires severe enough to substantially reduce the organic layer thickness and affect ground cover species are required to establish a productive regeneration layer on such sites. We succinctly review how understory vegetation influences black spruce ecosystem dynamics in eastern boreal Canada, and present a multi-scale research model to understand, limit the loss and restore productive and diverse ecosystems in this region. Our model integrates knowledge of plant-level mechanisms in the development of silvicultural tools to sustain productivity. Fundamental knowledge is integrated at stand, landscape, regional and provincial levels to understand the distribution and dynamics of ericaceous shrubs and paludification processes and to support tactical and strategic forest management. The model can be adapted and applied to other natural resource management problems, in other biomes.
      PubDate: 2013-07-23
      DOI: 10.3390/f4030613
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 632-649: Distribution and Variation of Forests in
           China from 2001 to 2011: A Study Based on Remotely Sensed Data
    • Authors: Xiang Zhao, Peipei Xu, Tao Zhou, Qing Li, Donghai Wu
      Pages: 632 - 649
      Abstract: Forests are one of the most important components of the global biosphere and have critical influences on the Earth’s ecological balance. Regularly updated forest cover information is necessary for various forest management applications as well as climate modeling studies. However, map products are not widely updated at continental or national scales because the current land cover products have overly coarse spatial resolution or insufficiently large training data sets. This study presents the results of forests distribution and variation information over China using Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) time series data with the first layer of MODIS Land Cover Type product (MODIS LC-1). The NDVI time series histogram characteristic curves for forestland were estimated from MODIS LC-1 and MODIS NDVI time series data. Based on the differences of histograms among different forests, we obtained the 2001–2011 forests distribution for China at a spatial resolution of 500-m × 500-m. The overall accuracy of validation was 80.4%, an increase of 12.8% relative to that obtained using MODIS LC-1 data. The 2001–2011 forestland pure and mixed pixels of China accounted for an average of 33.72% of all pixels. There is a gradual increase in China’s forestland coverage during 2001–2011; however, the relationship is not statistically significant.
      PubDate: 2013-08-02
      DOI: 10.3390/f4030632
      Issue No: Vol. 4, No. 3 (2013)
       
  • Forests, Vol. 4, Pages 650-665: Tree Species Richness and Stand
           Productivity in Low-Density Cluster Plantings with Oaks (Quercus robur L.
           and Q. petraea (Mattuschka) Liebl.)
    • Authors: Somidh Saha, Christian Kuehne, Jürgen Bauhus
      Pages: 650 - 665
      Abstract: Low density plantings complemented by natural regeneration is an increasingly common reforestation technique to ensure growth of a sufficient number of trees from desired species while maintaining natural processes such as succession. One such form of low density planting that aims at lowering establishment costs—oak clusters—has been developed as an alternative to row planting since the 1980s in central Europe. However, whether cluster planting provides higher species richness and productivity than high density row planting has not previously been analyzed. Here, we compare tree species richness and productivity (measured as stand basal area) between oak cluster plantings and conventional row planting in young (10–26 years old) forest stands at seven study sites in Germany. Tree species richness was significantly higher in cluster plantings than in row plantings, whereas total basal areas were comparable. Naturally regenerated trees contributed on average to 43% of total stand basal area in cluster plantings, which was significantly higher than in row plantings. Total stand basal area in cluster planting was significantly related to the density of naturally regenerated trees. In turn, tree species diversity, density and basal area of naturally regenerated trees were increased with the size of unplanted area between clusters. Our results demonstrate that the admixture of naturally regenerated, early and mid-successional tree species compensates for a possible loss in productivity from planting fewer oaks. Low density cluster plantings can offer significant environmental benefits, at least for the first few decades of stand development, without compromising productivity.
      PubDate: 2013-08-16
      DOI: 10.3390/f4030650
      Issue No: Vol. 4, No. 3 (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)
       
  • Forests, Vol. 4, Pages 218-233: Allometry for Biomass Estimation in
           Jatropha Trees Planted as Boundary Hedge in Farmers’ Fields
    • Authors: Stephy Makungwa, Abbie Chittock, David Skole, George Kanyama-Phiri, Iain Woodhouse
      Pages: 218 - 233
      Abstract: Regrowth and planted trees in agricultural landscapes are rarely protected from clearing under national Forest Acts. There is, therefore, some question over the long-term security of any value they might provide to biodiversity and the global carbon cycle. Engaging landholders in carbon credits that are conditioned on planted areas being maintained into the future could improve the situation. To begin carbon trading, landholders need precise and accurate estimates of the carbon sequestered by the trees in their fields. Accurate estimates of carbon stocks depend to a greater degree on the availability and adequacy of the allometric equations that are used to estimate tree biomass. The present study has developed an allometric model for estimating the woody biomass of Jatropha trees planted as boundary hedges in agricultural landscapes under smallholder farming systems in Malawi. The predictive performance of the model was assessed and was subsequently compared with the published Jatropha models. The results showed that the statistical fits of our model were generally good, enabling one to use it with confidence for estimating wood biomass in Jatropha stands from which they were derived. The published Jatropha models consistently overestimated the woody biomass by as much as 55%, rendering them unsuitable for application in estimating woody biomass in our study sites.
      PubDate: 2013-04-11
      DOI: 10.3390/f4020218
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 234-250: Wood Quality: A Perspective from New
           Zealand
    • Authors: John Walker
      Pages: 234 - 250
      Abstract: Forest products are commodities and subject to cyclical trends; yet resource-hungry countries offer exporters a period of sustained growth for those with the right products. Products have their distinctive requirements, e.g., finishing timber (colour, stability), structural (strength stiffness, stability), paper (fibre length and tear strength). The failure to incorporate such key properties in radiata pine (Pinus radiata) breeding programmes has been a lost opportunity for New Zealand forestry that constrains exports. Radiata pine remains a utilitarian, undifferentiated commodity. A complementary opportunity in international markets lies in naturally-durable eucalypts grown on New Zealand’s east coast drylands. These are species whose properties mimic those of the finest tropical hardwoods that are in most demand in Asian markets.
      PubDate: 2013-04-22
      DOI: 10.3390/f4020234
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 251-269: Specific Gravity of Hybrid Poplars in the
           North-Central Region, USA: Within-Tree Variability and Site ×
           Genotype Effects
    • Authors: William Headlee, Ronald Jr., Richard Hall, Edmund Bauer, Bradford Bender, Bruce Birr, Raymond Miller, Jesse Randall, Adam Wiese
      Pages: 251 - 269
      Abstract: Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most specific gravity reports are for a limited number of locations, resulting in a lack of information about the interactions between clones and sites over a wide range of climate and soil conditions. The objective of the current study was to characterize the effects of bole position, site, clone, and site × clone interactions for twelve hybrid poplar genotypes grown in Iowa, Minnesota, Wisconsin, and Michigan, USA. Observed specific gravities ranged from 0.267 to 0.495 (mean = 0.352 ± 0.001 for 612 samples taken from 204 trees), with bole position and site × clone interactions having significant effects on specific gravity. Further investigation of the site × clone interactions indicated that environmental conditions related to water stress were key predictors of specific gravity. These data are important for informing genotypic selection and silvicultural management decisions associated with growing hybrid poplars.
      PubDate: 2013-04-23
      DOI: 10.3390/f4020251
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 270-278: Effect of Nondestructive Evaluation of
           Veneers on the Properties of Laminated Veneer Lumber (LVL) from a Tropical
           Species
    • Authors: Cláudio Del Menezzi, Luana Mendes, Mário de Souza, Geraldo Bortoletto
      Pages: 270 - 278
      Abstract: This study aimed at evaluating the potential of Schizolobium parahyba to produce laminated veneer lumber (LVL) and the feasibility of a nondestructive method for grading the veneers. Initially, 64 S. parahyba veneers were nondestructively tested using the stress wave method, and stress wave velocity (wv) and veneer dynamic modulus of elasticity (EdV) were determined. Afterwards, the veneers were graded according to EdV descending values and used to manufacture 8-ply LVL boards. After the manufacturing, the boards were also nondestructively tested, and the board dynamic modulus of elasticity (EdB) was determined. Simple linear regression analysis was run to evaluate the relationship between the nondestructive and mechanical properties of veneers/boards. A positive effect of veneer stress wave properties on the LVL properties was found. Therefore, the higher the EdV values, the higher the LVL properties. The relationships between EdV and EdB properties were highly significant with all mechanical properties. It was clearly observed that when this grading procedure was used, the veneers were indirectly graded by their density. Finally, it could be concluded that S. parahyba showed good potential to produce LVL.
      PubDate: 2013-04-29
      DOI: 10.3390/f4020270
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 279-295: Impact of Forest Fragmentation on Patterns
           of Mountain Pine Beetle-Caused Tree Mortality
    • Authors: Christopher Bone, Joanne White, Michael Wulder, Colin Robertson, Trisalyn Nelson
      Pages: 279 - 295
      Abstract: The current outbreak of mountain pine beetle, Dendroctonus ponderosae Hopkins, has led to extensive tree mortality in British Columbia and the western United States. While the greatest impacts of the outbreak have been in British Columbia, ongoing impacts are expected as the outbreak continues to spread eastward towards Canada’s boreal and eastern pine forests. Successful mitigation of this outbreak is dependent on understanding how the beetle’s host selection behaviour is influenced by the patchwork of tree mortality across the landscape. While several studies have shown that selective mechanisms operate at the individual tree level, less attention has been given to beetles’ preference for variation in spatial forest patterns, namely forest fragmentation, and if such preference changes with changing population conditions. The objective of this study is to explore the influence of fragmentation on the location of mountain pine beetle caused mortality. Using a negative binomial regression model, we tested the significance of a fragmentation measure called the Aggregation Index for predicting beetle-caused tree mortality in the central interior of British Columbia, Canada in 2000 and 2005. The results explain that mountain pine beetle OPEN ACCESS Forests 2013, 4 280 exhibit a density-dependent dynamic behaviour related to forest patterns, with fragmented forests experiencing greater tree mortality when beetle populations are low (2000). Conversely, more contiguous forests are preferred when populations reach epidemic levels (2005). These results reinforce existing findings that bark beetles exhibit a strong host configuration preference at low population levels and that such pressures are relaxed when beetle densities are high.
      PubDate: 2013-04-29
      DOI: 10.3390/f4020279
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 296-318: Community Participation and Benefits in
           REDD+: A Review of Initial Outcomes and Lessons
    • Authors: Kathleen Lawlor, Erin Madeira, Jill Blockhus, David Ganz
      Pages: 296 - 318
      Abstract: The advent of initiatives to reduce emissions from deforestation and degradation and enhance forest carbon stocks (REDD+) in developing countries has raised much concern regarding impacts on local communities. To inform this debate, we analyze the initial outcomes of those REDD+ projects that systematically report on their socio-economic dimensions. To categorize and compare projects, we develop a participation and benefits framework that considers REDD+’s effects on local populations’ opportunities (jobs, income), security (of tenure and ecosystem services), and empowerment (participation in land use and development decisions). We find material benefits, in terms of jobs and income, to be, thus far, modest. On the other hand, we find that many projects are helping populations gain tenure rights. A majority of projects are obtaining local populations’ free, prior, and informed consent (FPIC). However, for those projects interacting with multiple populations, extent of participation and effects on forest access are often uneven. Our participation and benefits framework can be a useful tool for identifying the multi-faceted socio-economic impacts of REDD+, which are realized under different timescales. The framework and initial trends reported here can be used to build hypotheses for future REDD+ impact evaluations and contribute to evolving theories of incentive-based environmental policy.
      PubDate: 2013-05-10
      DOI: 10.3390/f4020296
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 319-328: Comparative Histopathology of Host
           Reaction Types in Slash Pine Resistant to Cronartium quercuum f. sp.
           fusiforme
    • Authors: Karina Gramacho, Thomas Miller, Robert Schmidt
      Pages: 319 - 328
      Abstract: Histological examinations of the host reaction types (RTs); short galls, rough galls and smooth galls in slash pine seedlings inoculated with Cronartium quercuum f. sp. fusiforme revealed host reaction zone(s) [RZ(s)]. These RZs differed among the host RTs in location and pattern of occurrence in the stem, staining reaction, periderm formation and amount of fungal colonization. The RZ within short galls were wide, deep in the cortex, continuous around the stem, bordered on both sides by a well-developed periderm encircling the stem with limited fungal colonization. The RZ of the rough galls lacked a periderm, were small, numerous and discontinuous around the stem circumference, being separated by symptomatic tissue typical of a susceptible reaction. Fungal colonization of the rough galls was limited and hyphae and haustoria were encrusted. The RZ of the smooth galls were small and narrow conforming to the stem circumference, shallow in the cortex and interconnected by symptomatic tissues typical of a susceptible reaction. A narrow periderm developed along the innermost portion of the RZ in smooth galls and fungal colonization was abundant in the cortex. We suggest that the RTs large galls (rough and smooth), short galls, and hypersensitive-like stem lesions represent increasing resistance to the fusiform rust pathogen.
      PubDate: 2013-05-10
      DOI: 10.3390/f4020319
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 329-342: Fostering Collaborations towards
           Integrative Research Development
    • Authors: Niels Brouwers, Susan Moore, Thomas Lyons, Giles Hardy, Jérôme Chopard, George Matusick, Katinka Ruthrof, Leonie Valentine
      Pages: 329 - 342
      Abstract: The complex problems associated with global change processes calls for close collaboration between science disciplines to create new, integrated knowledge. In the wake of global change processes, forests and other natural environments have been rapidly changing, highlighting the need for collaboration and integrative research development. Few tools are available to explore the potential for collaborations in research ventures that are just starting up. This study presents a useful approach for exploring and fostering collaborations between academics working in research teams and organizations comprising multiple science disciplines (i.e., multi-disciplinary). The research aim was to reveal potential barriers, common ground, and research strengths between academics working in a new centre focused on forest and climate change research. This aim was based on the premise that raising awareness and working with this acquired knowledge fosters collaborations and integrative research development. An email survey was deployed amongst the academics to obtain: (i) their understanding of common themes (e.g., climate change, scale of investigation, woodland/forest health/decline); (ii) descriptions of the spatial and temporal scales of their research; and (iii) their approach and perceived contributions to climate change research. These data were analysed using a semi-quantitative content analysis approach. We found that the main potential barriers were likely to be related to differences in understanding of the common research themes, whilst similarities and disciplinary strengths provided critical elements to foster collaborations. These findings were presented and discussed amongst the centre academics to raise awareness and create a dialogue around these issues. This process resulted in the development of four additional research projects involving multiple disciplines. The approach used in this study provides a useful methodology of broader benefit to similar multi-disciplinary research teams and organizations elsewhere.
      PubDate: 2013-05-10
      DOI: 10.3390/f4020329
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 343-363: Predicting Future Conflict under REDD+
           Implementation
    • Authors: Toral Patel, Ahmad Dhiaulhaq, David Gritten, Yurdi Yasmi, Toon De Bruyn, Naya Paudel, Harisharan Luintel, Dil Khatri, Chandra Silori, Regan Suzuki
      Pages: 343 - 363
      Abstract: With the current complexity of issues facing forest and land management, the implementation of the REDD+ initiative comes with significant risks, including conflict. While the exact nature and shape of conflict in REDD+ implementation is difficult to pinpoint, this study aims to build a preliminary predictive framework to identify possible sources of impairment that may result in conflict over management of forests and natural resources. The framework was developed from an extensive literature review and was tested in three REDD+ pilot project sites in Nepal. The results indicate that most of the sources of impairment are present in all study sites, particularly issues relating to benefit sharing, which have been main drivers of conflict prior to REDD+. While we found that the application of the framework has been useful in the Nepalese context, there are some limitations in its scope and precision. Nonetheless, this study points to important implications with regards to REDD+ implementation and conflict management that can be useful for policy makers and practitioners involved in REDD+ strategy designs, as well as other areas of forest management involving outsiders and communities.
      PubDate: 2013-05-10
      DOI: 10.3390/f4020343
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 364-385: Ecosystem Responses to Partial Harvesting
           in Eastern Boreal Mixedwood Stands
    • Authors: Suzanne Brais, Timothy Work, Émilie Robert, Christopher O'Connor, Manuella Strukelj, Arun Bose, Danielle Celentano, Brian Harvey
      Pages: 364 - 385
      Abstract: Partial harvesting has been proposed as a key aspect to implementing ecosystem management in the Canadian boreal forest. We report on a replicated experiment located in boreal mixedwoods of Northwestern Quebec. In the winter of 2000–2001, two partial harvesting treatments, one using a dispersed pattern, and a second, which created a (400 m2) gap pattern, were applied to a 90-year-old aspen-dominated mixed stand. The design also included a clear cut and a control. Over the course of the following eight years, live tree, coarse woody debris, regeneration and ground beetles were inventoried at variable intervals. Our results indicate that all harvesting treatments created conditions favorable to balsam fir (Abies balsamea) sapling growth and trembling aspen (Populus tremuloides) sapling recruitment. However, balsam fir and trembling aspen regeneration and ground beetles response to gap cuts were closer to patterns observed in clear cuts than in dispersed harvesting. The underlying reasons for these differing patterns can be linked to factors associated with the contrasting light regimes created by the two partial harvesting treatments. The study confirms that partially harvesting is an ecologically sound approach in boreal mixedwoods and could contribute to maintaining the distribution of stand ages at the landscape level.
      PubDate: 2013-05-22
      DOI: 10.3390/f4020364
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 386-403: Classification of Needle Loss of
           Individual Scots Pine Trees by Means of Airborne Laser Scanning
    • Authors: Tuula Kantola, Mikko Vastaranta, Päivi Lyytikäinen-Saarenmaa, Markus Holopainen, Ville Kankare, Mervi Talvitie, Juha Hyyppä
      Pages: 386 - 403
      Abstract: Forest disturbances caused by pest insects are threatening ecosystem stability, sustainable forest management and economic return in boreal forests. Climate change and increased extreme weather patterns can magnify the intensity of forest disturbances, particularly at higher latitudes. Due to rapid responses to elevating temperatures, forest insect pests can flexibly change their survival, dispersal and geographic distributions. The outbreak pattern of forest pests in Finland has evidently changed during the last decade. Projection of shifts in distributions of insect-caused forest damages has become a critical issue in the field of forest research. The Common pine sawfly (Diprion pini L.) (Hymenoptera, Diprionidae) is regarded as a significant threat to boreal pine forests. Defoliation by D. pini has resulted in severe growth loss and mortality of Scots pine (Pinus sylvestris L.) (Pinaceae) in eastern Finland. In this study, tree-wise defoliation was estimated for five different needle loss category classification schemes and for 10 different simulated airborne laser scanning (ALS) pulse densities. The nearest neighbor (NN) approach, a nonparametric estimation method, was used for estimating needle loss of 701 Scots pines, using the means of individual tree features derived from ALS data. The Random Forest (RF) method was applied in NN-search. For the full dense data (~20 pulses/m2), the overall estimation accuracies for tree-wise defoliation level varied between 71.0% and 86.5% (kappa-values of 0.56 and 0.57, respectively), depending on the classification scheme. The overall classification accuracies for two class estimation with different ALS pulse densities varied between 82.8% and 83.7% (kappa-values of 0.62 and 0.67, respectively). We conclude that ALS-based estimation of needle losses may be of acceptable accuracy for individual trees. Our method did not appear sensitive to the applied pulse densities.
      PubDate: 2013-06-14
      DOI: 10.3390/f4020386
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 404-432: District Council Members and the
           Importance of Member Involvement in Organization Renewal Processes in
           Swedish Forest Owners’ Associations
    • Authors: Thomas Kronholm, Dianne Wästerlund
      Pages: 404 - 432
      Abstract: The objective of this paper is to examine the organization renewal process in forest owners’ associations and the role of members in this process. Based on 15 qualitative interviews with district council members in a forest owners’ association, we describe the characteristics of today’s elected member representatives in terms of their motives for volunteering, their relationship with the organization, and the organizational practices and routines of the renewal process. It is shown that most district council members are traditional forest owners with a family history within the association and that the district councils are therefore not representative of all member groups. We thus argue that it will be important for the renewal process that the associations carefully consider how they want to be perceived by both current and potential members in order to encourage the involvement of different owner groups. The election committees, which prepare the elections to the councils and board, play an important role in the associations’ renewal processes and must become more active in their search for suitable candidates.
      PubDate: 2013-06-14
      DOI: 10.3390/f4020404
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 433-454: Afforestation of Boreal Open Woodlands:
           Early Performance and Ecophysiology of Planted Black Spruce Seedlings
    • Authors: Pascal Tremblay, Jean-Francois Boucher, Marc Tremblay, Daniel Lord
      Pages: 433 - 454
      Abstract: Open lichen woodlands (LWs) are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes of containerized black spruce (Picea mariana Mill. (BSP)) seedlings for their afforestation. We compared treatment of unproductive LWs to reforestation of harvested, closed-crown black spruce-feathermoss (BSFM) stands. After one year, seedling survival and nutritional status were equivalent among stand types but despite higher root elongation index (REI), planted seedlings in LWs had lower relative growth rate, smaller total biomass and stem diameter than those in BSFM stands. Soil fertility variables, soil temperature, nor seedling water potential, helped at explaining this early growth response. Disc scarification significantly improved seedling first-year survival, biomass and foliar nutrient concentrations of P, Ca, and Mg. Smaller planting stock showed higher REI, higher shoot water potential, and higher foliar nutrient concentration of all but one of the measured nutrients (N, P, K and Mg). Hence, preliminary results suggest that planting of smaller containerized black spruce stock, combined with disc scarification, shows potential for afforestation of unproductive LWs. The impact of the lichen mat and other potential growth limiting factors on afforestation of these sites requires further investigation.
      PubDate: 2013-06-20
      DOI: 10.3390/f4020433
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 455-470: Modeling Young Stand Development towards
           the Old-Growth Reference Condition in Evergreen Mixed-Conifer Stands at
           Headwaters Forest Reserve, California
    • Authors: John-Pascal Berrill, Christopher Beal, David LaFever, Christa Dagley
      Pages: 455 - 470
      Abstract: We sought to answer the question: How do we restore characteristics of old-growth evergreen mixed-conifer forests in young even-aged stands on upland terrain at Headwaters Forest Reserve (HFR)? We described the old-growth reference condition for three stands at HFR. In each old-growth stand, trees within a 1-ha plot were inventoried. We found coast Douglas-fir (Pseudotsuga menziesii var. menziesii) and tanoak (Notholithocarpus densiflorus) well represented while coast redwood (Sequoia sempervirens) dominated in terms of size. Numbers of understory and overstory trees ha−1 and average tree sizes were similar among sites, suggesting these were useful goals for restoration. Adjacent to each old-growth stand, we measured recent growth rates of second-growth trees and remnant old trees across a range of tree sizes, stand structures, and densities. The resultant growth models of redwood and Douglas-fir enabled us to project the development of precommercially thinned young stands at HFR forward in time under two silvicultural prescriptions: (i) no further management; and (ii) partial harvesting simulated before trees attained 30 cm dbh. The partial-harvesting prescription reduced stand density and set the young stand on a more rapid trajectory towards the reference condition found at HFR.
      PubDate: 2013-06-20
      DOI: 10.3390/f4020455
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 471-487: Above Ground Leafless Woody Biomass and
           Nutrient Content within Different Compartments of a P. maximowicii ×
           P. trichocarpa Poplar Clone
    • Authors: Christopher Morhart, Jonathan Sheppard, Heinrich Spiecker
      Pages: 471 - 487
      Abstract: In this study the quantification of biomass within all relevant compartments of a three-year-old poplar clone (P. maximowicii × P. trichocarpa) planted on abandoned agricultural land at a density of 5000 trees ha−1 is presented. A total of 30 trees within a diameter range of 1.8 cm to 8.9 cm, at breast height (dbh at 1.3 m), were destructively sampled. In order to analyze the biomass, the complete tree, stem, as well as all branches, were divided into 1 cm diameter classes and all buds from the trees were completely removed. Total yield was calculated as 11.7 odt ha−1 year−1 (oven dry tonnes per hectare and year). Branches constituted 22.2% of total dry leafless biomass and buds 2.0%. The analyses revealed a strong correlation of the dry weight for all the three compartments with diameter at breast height. Debarked sample discs were used to obtain a ratio between wood and bark. Derived from these results, a model was developed to calculate the biomass of bark with dbh as the predictor variable. Mean bark percentage was found to be 16.8% of above ground leafless biomass. The results concur that bark percentage decreases with increasing tree diameter, providing the conclusion that larger trees contain a lower bark proportion, and thus positively influence the quality of the end product while consequently reducing the export of nutrients from site.
      PubDate: 2013-06-20
      DOI: 10.3390/f4020471
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 488-499: Stability of Slash Pine Families with
           Major Gene and Partial Resistance to Single-Gall and Mixed-Gall Inocula of
           Cronartium quercuum fusiforme in Greenhouse Studies
    • Authors: Karina Gramacho, Robert Schmidt, Thomas Miller
      Pages: 488 - 499
      Abstract: Single-gall and mixed-gall inocula from fusiform rust (Cronartium quercuum fusiforme) galls in field studies were used in greenhouse tests to investigate their pathogenic variability and the temporal and spatial stability of fusiform rust incidence of resistant slash pine (Pinus elliottii var. elliottii) seedlings. Analyses of variance showed significant main effects for families and inocula and for the interactions of families and inocula indicating abundant pathogenic variation and differential family resistance. Averaged over all families and inocula, there were no significant differences between sequential inocula, i.e., inocula from successive generations of the pathogen. However, when analyzed separately Family R1 with segregated major gene resistance showed increased rust incidence with successive generations of the pathogen. Also Family R1 accounted for a major portion of the temporal (51.4%) and spatial (49.6%) interaction sum of squares. In contrast the other resistant families each accounted for a minor portion of this statistic. These results indicate pathogen virulence toward major gene resistance, possible selection for virulence and the relative instability of Family R1 compared with other resistance families.
      PubDate: 2013-06-20
      DOI: 10.3390/f4020488
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 500-516: Seed Size, the Only Factor Positively
           Affecting Direct Seeding Success in an Abandoned Field in Quebec, Canada
    • Authors: Annick St-Denis, Christian Messier, Daniel Kneeshaw
      Pages: 500 - 516
      Abstract: Direct tree seeding is potentially an economical technique for restoring forests on abandoned fields. However, the success of tree establishment depends on many factors related to species and seed characteristics, environmental conditions, competition and predation. We compared seedling emergence, survival and growth of six tree species of different seed sizes in a forest restoration project of abandoned fields. Species were seeded in plots with and without herbaceous vegetation and with and without protection from bird and mammal predation. Yellow birch (Betula alleghaniensis) did not emerge in all treatments, paper birch (Betula papyrifera) and tamarack (Larix laricina) had a seedling emergence rate lower than 1%, and sugar maple (Acer saccharum) had a low overall emergence rate of 6%. Seedling emergence reached 57% for northern red oak (Quercus rubra) and 34% for red pine (Pinus resinosa), but survival of oak after one year was much higher (92%) than pine seedlings (16%). Overall, protection from birds and mammals and elimination of the herbaceous vegetation cover had no detectable effects on seedling emergence, survival and height. Nonetheless, red oak seedlings growing in the presence of vegetation had a smaller diameter and shoot biomass and a larger specific leaf area. We conclude that only large seeded species, such as oak, should be used for forest restoration of abandoned fields by direct seeding in our region.
      PubDate: 2013-06-21
      DOI: 10.3390/f4020500
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 517: Dale W. Johnson, et al. The Long-Term Effects
           of Wildfire and Post-Fire Vegetation on Sierra Nevada Forest Soils.
           Forests 2012, 3, 398-416
    • Authors: Dale Johnson, Roger Walker, Michelle McNulty, Benjamin Rau, Watkins Miller, Brittany Johnson
      Pages: 517 - 517
      Abstract: The authors would like to add a co-author “Brittany G. Johnson” as sixth author in the published paper [1], doi: 10.3390/f3020398, website: http://www.mdpi.com/1999-4907/3/2/398. After publication, we discovered that we left our one deserving graduate student author from the published paper, Brittany G. Johnson, who helped in collecting data for this paper. The authors apologize for any convenience this may have caused.
      PubDate: 2013-06-21
      DOI: 10.3390/f4020517
      Issue No: Vol. 4, No. 2 (2013)
       
  • Forests, Vol. 4, Pages 1-27: The Validation of the Mixedwood Growth Model
           (MGM) for Use in Forest Management Decision Making
    • Authors: Mike Bokalo, Kenneth Stadt, Philip Comeau, Stephen Titus
      Pages: 1 - 27
      Abstract: We evaluated the Mixedwood Growth Model (MGM) at a whole model scale for pure and mixed species stands of aspen and white spruce in the western boreal forest. MGM is an individual tree-based, distance-independent growth model, designed to evaluate growth and yield implications relating to the management of white spruce, black spruce, aspen, lodgepole pine, and mixedwood stands in Alberta, British Columbia, Saskatchewan, and Manitoba. Our validation compared stand-level model predictions against re-measured data (volume, basal area, diameter at breast height (DBH), average and top height and density) from permanent sample plots using combined analysis of residual plots, bias statistics, efficiency and an innovative application of the equivalence test. For state variables, the model effectively simulated juvenile and mature stages of stand development for both pure and mixed species stands of aspen and white spruce in Alberta. MGM overestimates increment in older stands likely due to age-related pathology and weather-related stand damage. We identified underestimates of deciduous density and volume in Saskatchewan. MGM performs well for increment in postharvest stands less than 30 years of age. These results illustrate the comprehensive application of validation metrics to evaluate a complex model, and provide support for the use of MGM in management planning.
      PubDate: 2013-01-07
      DOI: 10.3390/f4010001
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 28-42: Frequency of False Heartwood of Stems of
           Poplar Growing on Farmland in Sweden
    • Authors: Tord Johansson, Birger Hjelm
      Pages: 28 - 42
      Abstract: Swedish owners of poplar stands are interested in both the wood quality and the use of poplars that are soon to be harvested. An important concern is the frequency of false heartwood (FHW) in the stems. We have presented an overview of the factors causing discolored wood as well as the industrial use and quality of the end products. We have studied poplar stems growing at 22 sites in Sweden between latitudes 55° N and 60° N. The mean age of the poplar was 23 years (range 14–41), the mean stand density 1011 stems ha−1 (range 155–3493) and the diameter at breast height (DBH) (over bark) 246 mm (range 121–447). All stands were growing on clay soils (light and medium clay and light clay tills). All of the sampled stems (42) contained false heartwood. At 0%–50% of stem height, all sampled trees were discolored and at 90% of stem height, 33% were discolored. The percentage of false heartwood area by stem area was highest at 1% and 10% of stem height (26.6% and 24.7% respectively). The “FHW” part of the stem had a radius of 47 mm (range 9–93) at 30% of stem height, which corresponds to 50% of the total stem radius. A log of six meters represents about 30% of stem height. Equations describing the correlation between DBH and the diameter of FHW at different stem heights (1%, 10%, 30%, 50%, 70% and 90%) and table describing FHW volume % by total stem volume at the first 50% of stem height were constructed. These might be helpful for estimating the percentage of fresh wood in a stem. However, most of the fast-growing poplars will be harvested as biofuel.
      PubDate: 2013-01-09
      DOI: 10.3390/f4010028
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 43-69: The Contribution of Managed and Unmanaged
           Forests to Climate Change Mitigation—A Model Approach at
           Stand Level for the Main Tree Species in Bavaria
    • Authors: Daniel Klein, Sebastian Höllerl, Markus Blaschke, Christoph Schulz
      Pages: 43 - 69
      Abstract: Forestry-based carbon sequestration projects demand a comprehensive quantification of the different climate change mitigation effects. In our study, we modeled a life cycle of managed pure stands consisting of the four main tree species in Bavaria (spruce, pine, beech and oak). For spruce and beech, an unmanaged stand was additionally integrated in order to analyze the differences in climate change mitigation effects compared to the managed stands. We developed a climate change mitigation model, where stand development and silvicultural treatments including harvested timber volumes were conducted using the tree growth model Silva 2.3. The harvested wood products (HWP), including their substitution effects were calculated with a subsequent model. For unmanaged beech forests, we compiled measured data from the literature, and Bavarian strict forest reserves for validating our model results. The results for the managed stands reveal that spruce provides the highest total climate change mitigation effects. After a simulation period of 180 years, one hectare leads to a mean mitigation benefit of 13.5 Mg CO2 ha−1 year−1. In comparison, results for pine, beech and oak reveal lesser benefits with 10.1 Mg CO2 ha−1 year−1, 9.1 Mg CO2 ha−1 year−1 and 7.2 Mg CO2 ha−1 year−1, respectively. However, these results assume current growing conditions. Considering climate change, it is very likely that spruce will not be suitable in several regions of Bavaria in the future. Furthermore, excessive disturbances could affect spruce more drastically than the other tree species. In that case, the order could change and beech could exceed spruce. Thus the results cannot be seen as a general recommendation to establish spruce stands in order to achieve optimal climate change mitigation benefits. Nevertheless, results for spruce illustrate that high increment and especially wood use in long-lived products is crucial for high climate change mitigation effects. Mitigation effects in unmanaged spruce and beech stands do not differ in the first decades from their managed counterparts, but are below them in the long term with a total climate change mitigation benefit of 8.0 Mg CO2 ha−1 year−1 and 7.2 Mg CO2 ha−1 year−1, respectively. These differences are mainly caused by the missing substitution effects in the unmanaged stands. However, the precise dimensions of substitution effects still remain uncertain and the lack of data should be reduced via additional life cycle assessments for more products and product classes. However, neglecting substitution effects in climate change mitigation models leads to severe underestimations of the mitigation effects in managed forests.
      PubDate: 2013-01-14
      DOI: 10.3390/f4010043
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 70-84: Leaf Rust of Wheat: Pathogen Biology,
           Variation and Host Resistance
    • Authors: James Kolmer
      Pages: 70 - 84
      Abstract: Rusts are important pathogens of angiosperms and gymnosperms including cereal crops and forest trees. With respect to cereals, rust fungi are among the most important pathogens. Cereal rusts are heteroecious and macrocyclic requiring two taxonomically unrelated hosts to complete a five spore stage life cycle. Cereal rust fungi are highly variable for virulence and molecular polymorphism. Leaf rust, caused by Puccinia triticina is the most common rust of wheat on a worldwide basis. Many different races of P. triticina that vary for virulence to leaf rust resistance genes in wheat differential lines are found annually in the US. Molecular markers have been used to characterize rust populations in the US and worldwide. Highly virulent races of P. triticina are selected by leaf rust resistance genes in the soft red winter wheat, hard red winter wheat and hard red spring wheat cultivars that are grown in different regions of the US. Cultivars that only have race-specific leaf rust resistance genes that are effective in seedling plants lose their effective resistance and become susceptible within a few years of release. Cultivars with combinations of race non-specific resistance genes have remained resistant over a period of years even though races of the leaf rust population have changed constantly.
      PubDate: 2013-01-16
      DOI: 10.3390/f4010070
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 85-103: The Importance of Microtopography and Nurse
           Canopy for Successful Restoration Planting of the Slow-Growing Conifer
           Pilgerodendron uviferum
    • Authors: Jan Bannister, Rafael Coopman, Pablo Donoso, Jürgen Bauhus
      Pages: 85 - 103
      Abstract: Recent studies have shown that, owing to a lack of seed trees, the natural rate of recovery of fire-disturbed bog forests previously dominated by the endemic and endangered conifer Pilgerodendron uviferum (D. Don) Florin is extremely slow. Hence, increasing the number of seed trees in the landscape through restoration planting could remove the principal biotic filter, limiting recovery of these forests. Here, we analyzed how the success of restoration plantings may be improved through the choice or manipulation of microsites in P. uviferum forests on Chiloé Island in North Patagonia. For this purpose, we manipulated microtopography in water-logged sites in bogs (mounds, flat terrain, mineral soil) and changed canopy conditions (gaps, semi-open, closed canopy) in upland sites with better drainage. In bogs, there was no significant effect of microtopography on growth and survival of P. uviferum plantings. However, fluorescence measurements indicated lower stress in seedlings established on mounds. Seedlings in upland areas established beneath a nurse canopy had lower mortality and higher relative shoot growth, foliar nutrients, photosynthetic light use efficiency and chlorophyll fluorescence values than those planted in the open. This indicates that seedlings of the slow growing P. uviferum can tolerate extremely wet conditions, yet suffer from stress when grown in the open. Here, the removal of canopy appeared to have also removed or reduced mycorrhizal networks for seedlings, leading to poorer nutrition and growth. Based on these results, recommendations for restoration plantings in highly degraded P. uviferum forests are presented.
      PubDate: 2013-01-16
      DOI: 10.3390/f4010085
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 104-105: Methods in Forest Canopy Research, Edited
           by Margaret D. Lowman, Timothy D. Schowalter, Jerry F. Franklin,
           University of California Press, 2012; 221 pages. Price:
           £41.95, ISBN978-0520-27371-9
    • Authors: Shu-Kun Lin
      Pages: 104 - 105
      Abstract: Poised between soil and sky, forest canopies represent a critical point of exchange between the atmosphere and the earth, yet until recently, they remained a largely unexplored frontier. For a long time, problems with access and the lack of tools and methods suitable for monitoring these complex bioscopes made canopy analysis extremely difficult. Fortunately, canopy research has advanced dramatically in recent decades. Methods in Forest Canopy Research is a comprehensive overview of these developments for explorers of this astonishing environment. The authors describe methods for reaching the canopy and the best ways to measure how the canopy, atmosphere, and forest floor interact. They address how to replicate experiments in challenging environments and lay the groundwork for creating standardized measurements in the canopy—essential tools for understanding our changing world.
      PubDate: 2013-01-28
      DOI: 10.3390/f4010104
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 106-121: Changes in Whole-Tree Water Use Following
           Live-Crown Pruning in Young Plantation-Grown Eucalyptus pilularis and
           Eucalyptus cloeziana
    • Authors: Philip Alcorn, David Forrester, Dane Thomas, Ryde James, R. Smith, Adrienne Nicotra, Jürgen Bauhus
      Pages: 106 - 121
      Abstract: Pruning of live branches is a management option to enhance wood quality in plantation trees. It may also alter whole-tree water use, but little is known about the extent and duration of changes in transpiration. In this study, sap flow sensors were used to measure transpiration for 14 days prior to, and 75 days following the removal, through pruning, of the lower 50% of the live-crown length of 10–11 m tall four-year old Eucalyptus pilularis Sm. and E. cloeziana F. Muell. trees. Pruning had no effect on stem growth, sapwood water content or radial pattern of sap velocity in either species. Pruning reduced mean daily water use by 39% in E. pilularis and 59% in E. cloeziana during the first eight days after pruning. Thirty six days after pruning there were no longer any significant differences in transpiration rates between pruned and unpruned trees in either species. Our results show that pruning of live branches had only a short-term effect on whole-tree transpiration in these sub-tropical eucalypt species.
      PubDate: 2013-02-05
      DOI: 10.3390/f4010106
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 122-136: Predicting Understory Species Richness
           from Stand and Management Characteristics Using Regression Trees
    • Authors: Nilesh Timilsina, Wendell Cropper, Francisco Escobedo, Joanna Lima
      Pages: 122 - 136
      Abstract: Managing forests for multiple ecosystem services such as timber, carbon, and biodiversity requires information on ecosystem structure and management characteristics. National forest inventory data are increasingly being used to quantify ecosystem services, but they mostly provide timber management and overstory data, while data on understory shrub and herbaceous diversity are limited. We obtained species richness and stand management data from relevant literature to develop a regression tree model that can be used to predict understory species richness from forest inventory data. Our model explained 57% of the variation in herbaceous species richness in the coastal plain pine forests of the southeastern USA. Results were verified using field data, and important predictors of herbaceous richness included stand age, forest type, time since fire, and time since herbicide-fertilizer application. This approach can make use of available forest inventories to rapidly and cost-effectively estimate understory species richness for subtropical pine forests.
      PubDate: 2013-02-22
      DOI: 10.3390/f4010122
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 137-154: Early Effects of Afforestation with Willow
           (Salix purpurea, “Hotel”) on Soil Carbon and Nutrient
           Availability
    • Authors: Joels Ens, Richard Farrell, Nicolas Bélanger
      Pages: 137 - 154
      Abstract: Willow (Salix spp.) is currently being researched as a source of biomass energy in Canada. However, it is not certain whether afforestation with willow plantations will enhance or diminish soil C storage and nutrient availability. Trees are known to have pronounced effects on biologically mediated nutrient cycling processes which can increase nutrient availability, but willows are known to be nutrient demanding. In this paper, the net effect of plantation establishment is examined at nine sites across the prairie and southern Ontario regions of Canada. Carbon, N, P, K, Ca and Mg levels in soils and harvestable biomass were compared between willow plantations and paired reference sites at the end of the first three-year rotation. Soils were depleted in total C (−2.22 mg·g−1, p < 0.05), inorganic N (−3.12 μg·N·g−1, p < 0.10), exchangeable K (−0.11 cmolc·kg−1, p < 0.10) and leachable P (−0.03 mg·g−1, p < 0.10). Exchangeable Ca was found to be consistently depleted only at the 20–40 depth. Depletion of soil K was more heavily influenced by disturbance, whereas soil N was directly affected by willow N uptake. Sites with greater growth and biocycling stabilized soil P concentrations.
      PubDate: 2013-03-12
      DOI: 10.3390/f4010137
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 155-178: Selection of Provenances to Adapt Tropical
           Pine Forestry to Climate Change on the Basis of Climate Analogs
    • Authors: Christoph Leibing, Johannes Signer, Maarten van Zonneveld, Andrew Jarvis, William Dvorak
      Pages: 155 - 178
      Abstract: Pinus patula and Pinus tecunumanii play an important role in the forestry sector in the tropics and subtropics and, in recent decades, members of the International Tree Breeding and Conservation Program (Camcore) at North Carolina State University have established large, multi-site provenance trials for these pine species. The data collected in these trials provide valuable information about species and provenance choice for plantation establishment in many regions with different climates. Since climate is changing rapidly, it may become increasingly difficult to choose the right species and provenance to plant. In this study, growth performance of plantings in Colombia, Brazil and South Africa was correlated to the degree of climatic dissimilarity between planting sites. Results are used to assess the suitability of seed material under a changing climate for four P. patula provenances and six P. tecunumanii provenances. For each provenance, climate dissimilarities based on standardized Euclidean distances were calculated and statistically related to growth performances. We evaluated the two methods of quantifying climate dissimilarity with extensive field data based on the goodness of fit and statistical significance of the climate distance relation to differences in height growth. The best method was then used as a predictor of a provenance change in height growth. The provenance-specific models were used to predict provenance performance under different climate change scenarios. The developed provenance-specific models were able to significantly relate climate similarity to different growth performances for five out of six P. tecunumanii provenances. For P. patula provenances, we did not find any correlation. Results point towards the importance of the identification of sites with stable climates where high yields are achievable. In such sites, fast-growing P. tecunumanii provenances with a high but narrow growth optimum can be planted. At sites with climate change of uncertain direction and magnitude, the choice of P. patula provenances, with greater tolerance towards different temperature and precipitation regimes, is recommended. Our results indicate that the analysis of provenance trial data with climate similarity models helps us to (1) maintain plantation productivity in a rapidly changing environment; and (2) improve our understanding of tree species’ adaptation to a changing climate.
      PubDate: 2013-03-20
      DOI: 10.3390/f4010155
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 179-196: Aboveground Tree Biomass for Pinus
           ponderosa in Northeastern California
    • Authors: Martin Ritchie, Jianwei Zhang, Todd Hamilton
      Pages: 179 - 196
      Abstract: Forest managers need accurate biomass equations to plan thinning for fuel reduction or energy production. Estimates of carbon sequestration also rely upon such equations. The current allometric equations for ponderosa pine (Pinus ponderosa) commonly employed for California forests were developed elsewhere, and are often applied without consideration potential for spatial or temporal variability. Individual-tree aboveground biomass allometric equations are presented from an analysis of 79 felled trees from four separate management units at Blacks Mountain Experimental Forest: one unthinned and three separate thinned units. A simultaneous set of allometric equations for foliage, branch and bole biomass were developed as well as branch-level equations for wood and foliage. Foliage biomass relationships varied substantially between units while branch and bole biomass estimates were more stable across a range of stand conditions. Trees of a given breast height diameter and crown ratio in thinned stands had more foliage biomass, but slightly less branch biomass than those in an unthinned stand. The observed variability in biomass relationships within Blacks Mountain Experimental Forest suggests that users should consider how well the data used to develop a selected model relate to the conditions in any given application.
      PubDate: 2013-03-21
      DOI: 10.3390/f4010179
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 4, Pages 197-217: Spatial Characterization of Wildfire
           Orientation Patterns in California
    • Authors: Ana Barros, José Pereira, Max Moritz, Scott Stephens
      Pages: 197 - 217
      Abstract: Using 100 years of fire perimeter maps, we investigate the existence of geographical patterns in fire orientation across California. We computed fire perimeter orientation, at the watershed level, using principal component analysis. Circular statistics were used to test for the existence of preferential fire perimeter orientations. Where perimeters displayed preferential orientation, we searched for evidence of orographic channeling by comparing mean fire orientation with watershed orientation. Results show that in California, 49% of the burnt area is associated with watersheds, where fires displayed preferential orientation. From these, 25% of the burnt area is aligned along the NE/SW orientation and 18% in the E/W orientation. In 27 out of 86 watersheds with preferential fire alignment, there is also correspondence between mean fire orientation and watershed orientation. Topographic influence on fire spread and dominant wind patterns during the fire season can account for the consistency in fire perimeter orientation in these regions. Our findings highlight the historical pattern of fire perimeter orientation and identify watersheds with potential orographic channeling.
      PubDate: 2013-03-22
      DOI: 10.3390/f4010197
      Issue No: Vol. 4, No. 1 (2013)
       
  • Forests, Vol. 3, Pages 853-863: Response of the Invasive Grass Imperata
           cylindrica to Disturbance in the Southeastern Forests, USA
    • Authors: Eric J. Holzmueller, Shibu Jose
      Pages: 853 - 863
      Abstract: Imperata cylindrica is an invasive plant species that threatens diversity and forest productivity in southeastern ecosystems. We examined the effects of disturbance events, particularly fire and hurricane/salvage harvesting, to determine the effects on I. cylindrica abundance in longleaf pine (Pinus palustris) forests in the Florida panhandle. Areas that were burned or had greater biomass removal following a hurricane had a greater number of I. cylindrica patches and larger patch size. These results highlight the importance of disturbance events on expanding invasive species populations in this region and are likely applicable for other invasive species as well. Monitoring and treatment should follow disturbance events to ensure that invasive species populations do not exceed unmanageable levels.
      PubDate: 2012-09-26
      DOI: 10.3390/f3040853
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 864-880: Industrial Round-Wood Damage and
           Operational Efficiency Losses Associated with the Maintenance of a
           Single-Grip Harvester Head Model: A Case Study in Russia
    • Authors: Yuri Gerasimov, Alexander Seliverstov, Vladimir Syunev
      Pages: 864 - 880
      Abstract: A field-based study was performed to broaden our knowledge of operational efficiency losses associated with the neglect of the proper maintenance of the delimbing and feeding mechanisms of a harvester. The post-harvest assessments of industrial round-wood (IRW) processing damage, fuel consumption and productivity were examined in clearcutting operations. Observations were made of seven combinations of wear levels of feed rollers (A—heavy, B—medium, C and C’—without wear) and sharpening states of delimbing knives (1—incorrect, 2—correct), depending on the degree of feed roller wear and matching of angles of knife blades to the technical requirements. The processing defects of IRW were broken down into unprocessed branches, bark stripping, and damage caused by feed roller spikes. The results were then compared with the effective quality requirements, and the IRW losses in terms of the reject rates (RR) were determined in the context of the technical condition. The most frequent damage was by unprocessed branches. The harvester with correctly sharpened knives produced the minimum RR (4% of pine, 6% of spruce and 6% birch logs). The quality of IRW harvested under B1 and C1 resulted in 6%, 6% and 8%. A1 turned out to be the lowest (12%, 10% and 8%). Improvement in the maintenance of delimbing knives can reduce the RR of IRW by 5%. Timely restoration of worn-out rollers can increase productivity by 2% and reduce fuel consumption by 5%.
      PubDate: 2012-09-27
      DOI: 10.3390/f3040864
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 881-895: Can REDD+ Save the Forest' The Role of
           Payments and Tenure
    • Authors: Edward B. Barbier, Anteneh T. Tesfaw
      Pages: 881 - 895
      Abstract: A recent policy response to halting global forest deforestation and degradation, and any resulting greenhouse gas emissions is REDD+, which also includes the role of conservation, sustainable management of forests and enhancement of forest carbon stocks. Although still in its infancy, the success of REDD+ will depend significantly on whether it can be economically viable and if any resulting payments are sufficient to cover the opportunity cost plus any transaction cost. Where tenure security over forest is weak, REDD+ can pose a risk for forest communities, who could be dispossessed, excluded and marginalized. This review of existing studies explores how payment for avoided deforestation, and forest tenure impact the success of REDD+ projects in terms of effectiveness, efficiency and equity. Effectiveness refers to the difference between deforestation with and without REDD+, efficiency refers to avoiding deforestation at minimal cost, and equity refers to the implication of REDD+ on benefit sharing. We conclude that the potential success or failure of REDD+ as a means to reduce deforestation and carbon emission on forest commons depends critically on designing projects that work within existing informal tenure institutions to ensure that carbon storage benefits align with livelihood benefits.
      PubDate: 2012-10-01
      DOI: 10.3390/f3040881
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 896-902: Plant Invasions: Symptoms and Contributors
           Rather Than Causes of Environmental Degradation
    • Authors: Vic Jurskis
      Pages: 896 - 902
      Abstract: Native or exotic woody plants can proliferate in dry and moist eucalypt ecosystems shading out many other native species, contributing to chronic decline of eucalypts and reinforcing unnatural fire regimes and nutrient cycling processes. Whether native or exotic, they proliferate as a consequence of disturbances which impact directly on these ecosystems. The most extensive ongoing disturbance since European occupation of Australia has been the disruption of frequent mild burning by humans. This burning maintained dynamically stable nutrient cycling processes and a competitive balance in dry and moist eucalypt systems and prevented plant “invasions”.
      PubDate: 2012-10-08
      DOI: 10.3390/f3040896
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 903-922: The Sign and Strength of Plant-Soil
           Feedback for the Invasive Shrub, Lonicera maackii, Varies in Different
           Soils
    • Authors: Kelly Schradin, Don Cipollini
      Pages: 903 - 922
      Abstract: Plants alter soil characteristics causing changes in their subsequent growth resulting in positive or negative feedback on both their own fitness and that of other plants. In a greenhouse study, we investigated whether the sign and strength of feedback changed across two distinct soil types, and whether effects were due to shifts in biotic or abiotic soil traits. Using soils from two different locations, we examined growth of the exotic invasive shrub, Lonicera maackii and the related native shrub, Diervilla lonicera, in unconditioned soils and in soils conditioned by previous growth of L. maackii, D. lonicera, and Fraxinus pennsylvanica. In a sandy acidic soil, L. maackii showed positive feedback in unsterilized soils, but its growth decreased and positive feedback became negative with sterilization in this soil. In a loamy circumneutral soil, L. maackii displayed neutral to negative feedback in unsterilized soils, but sterilization significantly increased growth in all conditioning treatments and caused feedback to become strongly negative. Native D. lonicera displayed negative feedback in unsterilized soil of both the sandy and loamy types, but sterilization either eliminated or reversed feedback relationships. Soil conditioning by L. maackii and F. pennsylvanica had very similar feedbacks on L. maackii and D. lonicera. While some abiotic soil traits varied across soil types and were affected by conditioning, soil biota sensitive to sterilization were apparently important mediators of both positive and negative feedback effects.
      PubDate: 2012-10-16
      DOI: 10.3390/f3040903
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 923-943: Recreation in Different Forest Settings: A
           Scene Preference Study
    • Authors: Louise Eriksson, Annika M. Nordlund, Olof Olsson, Kerstin Westin
      Pages: 923 - 943
      Abstract: Recreation activity preferences in forest settings were explored in a scene preference study. The importance of type of human intervention and the level of biodiversity for preference and intention to engage in recreation activities were examined in a sample of forestry and social science students in Sweden. Results showed that forestry students displayed an almost equally strong preference for natural-looking scenes as for scenes with traces of recreation (e.g., paths), whereas social science students preferred recreational scenes the most. Least preferred were scenes with traces of forest management. Different forest settings were furthermore preferred for different recreation activities. Recreational settings were favored for walking and going on outings, and natural-looking settings were more appreciated for picking berries or mushrooms. Respondents displayed a stronger intention to study plants and animals in high biodiversity settings and the intention to exercise was stronger in low biodiversity settings. Implications for future land use planning and forest management are discussed.
      PubDate: 2012-10-18
      DOI: 10.3390/f3040923
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 944-958: Charcoal and Total Carbon in Soils from
           Foothills Shrublands to Subalpine Forests in the Colorado Front Range
    • Authors: Christopher Licata, Robert Sanford
      Pages: 944 - 958
      Abstract: Temperate conifer forests in the Colorado Front Range are fire-adapted ecosystems where wildland fires leave a legacy in the form of char and charcoal. Long-term soil charcoal C (CC) pools result from the combined effects of wildland fires, aboveground biomass characteristics and soil transfer mechanisms. We measured CC pools in surface soils (0–10 cm) at mid-slope positions on east facing aspects in five continuous foothills shrubland and conifer forest types. We found a significant statistical effect of vegetation type on CC pools along this ecological gradient, but not a linear pattern increasing with elevation gain. There is a weak bimodal pattern of CC gain with elevation between foothills shrublands (1.2 mg CC ha−1) and the lower montane, ponderosa pine (1.5 mg CC ha−1) and Douglas-fir (1.5 mg CC ha−1) forest types prior to a mid-elevation decline in upper montane lodgepole pine forests (1.2 mg CC ha−1) before increasing again in the spruce/subalpine fir forests (1.5 mg CC ha−1). We propose that CC forms and accumulates via unique ecological conditions such as fire regime. The range of soil CC amounts and ratios of CC to total SOC are comparable to but lower than other regional estimates.
      PubDate: 2012-10-22
      DOI: 10.3390/f3040944
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 959-985: Oribatid Mite Community Decline Two Years
           after Low-Intensity Burning in the Southern Cascade Range of California,
           USA
    • Authors: Michael Camann, Karen Lamoncha, Nancy Gillette
      Pages: 959 - 985
      Abstract: To assess effects of low-intensity fire, we combined two silvicultural prescriptions with prescribed fire in the California Cascade Range. In the first treatment, two 100-ha stands were thinned to reduce density while retaining old-growth structural characteristics, yielding residual stands with high structural diversity (HSD). Two other 100-ha plots were thinned to minimize old growth structure, producing even-aged stands of low structural diversity (LSD), and one 50-ha split-plot from each treatment was burned. In addition, two 50 ha old-growth Research Natural Areas (RNA) were selected as untreated reference plots, one of which was also burned. Fire treatments profoundly altered mite assemblages in the short term, and forest structure modification likely exacerbated that response. Sampling conducted two years following treatment confirmed a continuing decline in oribatid mite abundance. Oribatid species richness and assemblage heterogeneity also declined, and community dominance patterns were disrupted. Oribatid responses to fire were either more intense or began earlier in the LSD treatments, suggesting that removal of old-growth structure exacerbated mite responses to fire. Prostigmatids recovered quickly, but their populations nonetheless diminished significantly in burned split-plots. Mite assemblage responses to prescribed fire were continuing nearly two years later, with no clear evidence of recovery.
      PubDate: 2012-10-24
      DOI: 10.3390/f3040959
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 986-996: Diversity, Vertical Stratification and
           Co-Occurrence Patterns of the Mycetophilid Community among Eastern
           Hemlock, Tsuga canadensis (L.) Carrière, in the Southern
           Appalachians
    • Authors: Carla Coots, Paris Lambdin, Jerome Grant, Rusty Rhea
      Pages: 986 - 996
      Abstract: Over 400 species of insects have been found in association with eastern hemlock in the southern Appalachians. Eastern hemlock stands provide an ideal habitat for all life stages of mycetophilids. However, the diversity, distribution and co-occurrence patterns of these species throughout the tree canopy are unknown. This study was initiated to evaluate abundance, species richness and species composition within three designated strata in the canopy of eastern hemlock, assess species for vertical stratification patterns, and determine if co-occurrence patterns of mycetophilid species are random or non-random. During this study, 24 species representing 14 genera were identified and evaluated. Mycetophilid abundance, species richness and composition differed among the lower, middle, and upper strata. Unique assemblages were identified in each stratum, indicating vertical stratification. The upper stratum of the canopy had four exclusive species, the middle had six exclusive species, and the lower stratum had nine exclusive species. The co-occurrence pattern of mycetophilid species in the canopy of eastern hemlock was non-random.
      PubDate: 2012-10-24
      DOI: 10.3390/f3040986
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 997-1016: Invasive Plant Species in the National
           Parks of Vietnam
    • Authors: Dang Tan, Pham Thu, Bernard Dell
      Pages: 997 - 1016
      Abstract: The impact of invasive plant species in national parks and forests in Vietnam is undocumented and management plans have yet to be developed. Ten national parks, ranging from uncut to degraded forests located throughout Vietnam, were surveyed for invasive plant species. Transects were set up along roads, trails where local people access park areas, and also tracks through natural forest. Of 134 exotic weeds, 25 were classified as invasive species and the number of invasive species ranged from 8 to 15 per park. An assessment of the risk of invasive species was made for three national parks based on an invasive species assessment protocol. Examples of highly invasive species were Chromolaena odorata and Mimosa diplotricha in Cat Ba National Park (island evergreen secondary forest over limestone); Mimosa pigra, Panicum repens and Eichhornia crassipes in Tram Chim National Park (lowland wetland forest dominated by melaleuca); and C. odorata, Mikania micrantha and M. diplotricha in Son Tra Nature Conservation area (peninsula evergreen secondary forest). Strategies to monitor and manage invasive weeds in forests and national parks in Vietnam are outlined.
      PubDate: 2012-10-30
      DOI: 10.3390/f3040997
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 1017-1033: American Chestnut Growth and Survival
           Five Years after Planting in Two Silvicultural Treatments in the Southern
           Appalachians, USA
    • Authors: Stacy Clark, Henry McNab, David Loftis, Stanley Zarnoch
      Pages: 1017 - 1033
      Abstract: The ability to restore American chestnut (Castanea dentata) through the planting of blight-resistant (Cryphonectria parasitica) trees is currently being tested. Forest-based research on the species’ silvicultural requirements and chestnut blight development are lacking. Pure American chestnut seedlings were planted in a two-age shelterwood forest with low residual basal area and in a midstory-removal treatment with high residual basal area. Survival did not differ between silvicultural treatments and averaged 67 percent across both treatments by the fifth year. Trees in the two-age shelterwood were 2.36 m and 16.8 mm larger in height and ground-line diameter, respectively, compared to trees in the midstory-removal by the fifth growing season. Blight occurrence was not affected by silvicultural treatment. Exploratory analyses indicated that seedling grading at planting and keeping trees free-to-grow through competition control would have resulted in a two-year gain in height and GLD growth in the two-age shelterwood treatment. The two-age shelterwood represented the most efficacious prescription for chestnut restoration, but the midstory-removal prescription may offer a reasonable alternative in areas where harvesting must be delayed.
      PubDate: 2012-11-09
      DOI: 10.3390/f3041017
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 1034-1070: Fire Effects on Soils in Lake States
           Forests: A Compilation of Published Research to Facilitate Long-Term
           Investigations
    • Authors: Jessica Miesel, P. Goebel, R. Corace, David Hix, Randall Kolka, Brian Palik, David Mladenoff
      Pages: 1034 - 1070
      Abstract: Fire-adapted forests of the Lake States region are poorly studied relative to those of the western and southeastern United States and our knowledge base of regional short- and long-term fire effects on soils is limited. We compiled and assessed the body of literature addressing fire effects on soils in Lake States forests to facilitate the re-measurement of previous studies for the development of new long-term datasets, and to identify existing gaps in the regional knowledge of fire effects on forest soils. Most studies reviewed addressed fire effects on chemical properties in pine-dominated forests, and long-term (>10 years) studies were limited. The major gaps in knowledge we identified include: (1) information on fire temperature and behavior information that would enhance interpretation of fire effects; (2) underrepresentation of the variety of forest types in the Lake States region; (3) information on nutrient fluxes and ecosystem processes; and (4) fire effects on soil organisms. Resolving these knowledge gaps via future research will provide for a more comprehensive understanding of fire effects in Lake States forest soils. Advancing the understanding of fire effects on soil processes and patterns in Lake States forests is critical for designing regionally appropriate long-term forest planning and management activities.
      PubDate: 2012-11-19
      DOI: 10.3390/f3041034
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 1071-1085: Phosphorus Fertilizer Rate, Soil P
           Availability, and Long-Term Growth Response in a Loblolly Pine Plantation
           on a Weathered Ultisol
    • Authors: D. Andrew Scott, Christine M. Bliss
      Pages: 1071 - 1085
      Abstract: Phosphorus is widely deficient throughout the southern pine region of the United States. Growth responses to P fertilization are generally long-lasting in a wide range of soil types, but little is known about fertilization rates and long-term P cycling and availability. In 1982, exceptionally high P fertilization rates (0, 81, 162, and 324 kg P ha−1) were applied to a loamy Ultisol in central Louisiana, USA. We measured vegetation responses at age 27 years and sequentially extracted soil P to 1 m to elucidate potential P availability into the next rotation. Loblolly pine responded well to the lowest fertilization rate; total biomass was 39% greater in the fertilized plots compared to the unfertilized plots, but higher fertilization rates had no effect, presumably due to induced N-limitations. What little fertilizer P was found in the soils was in the moderately labile NaOH fraction in the surface 20 cm, and may be slowly available to the next pine rotation. Normal rates of P fertilizer will maintain elevated available P well into a second rotation in loamy Pleisteocene Ultisols of the western Gulf Coastal Plain. Exceptionally high rates were not effective at increasing potentially available P beyond normal rates.
      PubDate: 2012-11-22
      DOI: 10.3390/f3041071
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 1086-1103: Effects of Initial Stand Density and
           Climate on Red Pine Productivity within Huron National Forest, Michigan,
           USA
    • Authors: Matthew Magruder, Sophan Chhin, Andrew Monks, Joseph O'Brien
      Pages: 1086 - 1103
      Abstract: Changes in climate are predicted to significantly affect the productivity of trees in the Great Lakes region over the next century. Forest management decisions, such as initial stand density, can promote climatic resiliency and moderate decreased productivity through the reduction of tree competition. The influences of climate (temperature and precipitation) and forest management (initial stand density) on the productivity of red pine (Pinus resinosa) across multiple sites within Huron National Forest, Michigan, were examined using dendrochronological methods. Two common planting regimes were compared in this analysis; low initial density (<988 trees per hectare) and high initial density (>1977 trees per hectare). Low initial density stands were found to have a higher climatic resilience by combining equal or greater measures of productivity, while having a reduced sensitivity to monthly and seasonal climate, particularly to summer drought.
      PubDate: 2012-12-17
      DOI: 10.3390/f3041086
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 1104-1132: Modeling Survival, Yield, Volume
           
    • Authors: Carlos Gonzalez-Benecke, Salvador Gezan, Daniel Leduc, Timothy Martin, Wendell Cropper, Lisa Samuelson
      Pages: 1104 - 1132
      Abstract: Longleaf pine (Pinus palustris Mill.) is an important tree species of the southeast U.S. Currently there is no comprehensive stand-level growth and yield model for the species. The model system described here estimates site index (SI) if dominant height (Hdom) and stand age are known (inversely, the model can project Hdom at any given age if SI is known). The survival (N) equation was dependent on stand age and Hdom, predicting greater mortality on stands with larger Hdom. The function that predicts stand basal area (BA) for unthinned stands was dependent on N and Hdom. For thinned stands BA was predicted with a competition index that was dependent on stand age. The function that best predicted stand stem volume (outside or inside bark) was dependent on BA and Hdom. All functions performed well for a wide range of stand ages and productivity, with coefficients of determination ranging between 0.946 (BA) and 0.998 (N). We also developed equations to estimate merchantable volume yield consisting of different combinations of threshold diameter at breast height and top diameter for longleaf pine stands. The equations presented in this study performed similarly or slightly better than other reported models to estimate future N, Hdom and BA. The system presented here provides important new tools for supporting future longleaf pine management and research.
      PubDate: 2012-12-18
      DOI: 10.3390/f3041104
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 1133-1156: Spatial and Temporal Responses to an
           Emissions Trading Scheme Covering Agriculture and Forestry: Simulation
           Results from New Zealand
    • Authors: Suzi Kerr, Simon Anastasiadis, Alex Olssen, William Power, Levente Timar, Wei Zhang
      Pages: 1133 - 1156
      Abstract: We perform simulations using the integrated Land Use in Rural New Zealand (LURNZ) model to analyze the effect of various New Zealand emissions trading scheme (ETS) scenarios on land use, emissions and output in a temporally and spatially explicit manner. We compare the impact of afforestation to the impact of other land-use change on net greenhouse gas emissions and evaluate the importance of the forestry component of the ETS relative to the agricultural component. We find that the effect of including agriculture in the ETS is small relative to the effect of including forestry. We also examine the effect of land-use change on the time profile of net emissions from the forestry sector. Finally, we present projections of future agricultural output under various policy scenarios.
      PubDate: 2012-12-18
      DOI: 10.3390/f3041133
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 1157-1179: Barriers and Bridges to U.S. Forest
           Service—Community Relationships: Results from Two Pilot
           Tests of a Rapid Social Capital Assessment Protocol
    • Authors: Jordan Smith
      Pages: 1157 - 1179
      Abstract: Successful management of national forests in the United States requires Forest Service personnel to collaborate with the public, including individuals living in communities near national forest lands. Collaboration enables agency personnel to build long-term trusting and reciprocal relationships with local communities through their ongoing planning processes. However, frequently agency personnel do not have the tools or data necessary to measure the strength of relationships that exist between the agency and local communities. A rapid social capital assessment protocol is presented that can be used by agency personnel and social scientists as a tool for gauging the existence and strength of Forest Service—community relationships. The utility of the protocol is illustrated by describing findings from two pilot tests conducted in communities near the Tombigbee National Forest in Mississippi and the Nantahala National Forest in North Carolina. Barriers to effective Forest Service—community relationships are highlighted and opportunities for social capital development, such as utilizing local news outlets, are presented.
      PubDate: 2012-12-18
      DOI: 10.3390/f3041157
      Issue No: Vol. 3, No. 4 (2012)
       
  • Forests, Vol. 3, Pages 736-744: Leakage Implications for European Timber
           Markets from Reducing Deforestation in Developing Countries
    • Authors: Ragnar Jonsson, Werner Mbongo, Adam Felton, Mattias Boman
      Pages: 736 - 744
      Abstract: Forest management strategies and policies such as REDD (reduced emissions from deforestation and forest degradation) may have unintentional implications for forest sectors in countries not targeted by such policies. The success of a policy effort like REDD would result in a significant reduction in deforestation and forest degradation and an ensuing reduction in the supply of natural forest timber production within participating countries. This could in turn result in price increases, inducing a supply response outside project boundaries with possible implications for forest management as well as global carbon emissions. This paper reviews the literature to discern potential timber market implications for countries sourcing wood products from developing countries affected by REDD related conservation efforts. The literature reviewed shows varying degrees of market effects leakage—policy actions in one place creating incentives for third parties to increase timber harvesting elsewhere through the price mechanism—ranging from negligible to substantial. However, wood products in the studies reviewed are dealt with on quite an aggregated scale and are assumed to be more or less perfect substitutes for wood products outside conservation effort boundaries. The review suggests that a thorough mapping of the end-uses of tropical timber is needed to comprehensively analyze impacts on wood-product markets in regions such as Europe from conservation efforts in tropical developing countries. The types of tropical timber expected to be affected, in which applications they are used, which are the most likely substitutes and where they would be sourced, are issues that, along with empirical analysis of supply and demand price elasticities and degree of substitutability, should be investigated when assessing the overall effectiveness of REDD.
      PubDate: 2012-08-27
      DOI: 10.3390/f3030736
      Issue No: Vol. 3, No. 3 (2012)
       
  • Forests, Vol. 3, Pages 745-763: Arboricultural Introductions and Long-Term
           Changes for Invasive Woody Plants in Remnant Urban Forests
    • Authors: Robert E. Loeb
      Pages: 745 - 763
      Abstract: Long-term changes for invasive trees and shrubs presence in 16 floras encompassing four remnant urban forests of the coastal northeastern United States were examined for relationships with arboricultural introductions’ residence time and planting intensity, and state level recognition of regional invasive woody taxa. The number of invasive woody taxa significantly increased over the period 1818 to 2011 which encompasses the 16 floras. No significant Pearson product moment correlations were found for residence time as the year of introduction to arboriculture with presence in the 16 floras as well as with the 4 most recent floras. In contrast to residence time, planting intensity from the North American flora and two botanical gardens floras of the region from 1811 to 1818 and New York and Philadelphia parks floras from 1857 to 1903 did have significant correlations with the 16 floras and the 4 most recent floras. State level recognition of regional invasive woody taxa showed significant correlations with presence in all 16 floras as well as the 4 most recent floras. Monitoring for range expansion by the regional invasive woody taxa is essential because only 18% of the 98 taxa are present in all 4 of the most recent floras.
      PubDate: 2012-08-27
      DOI: 10.3390/f3030745
      Issue No: Vol. 3, No. 3 (2012)
       
  • Forests, Vol. 3, Pages 764-786: Spatial Analysis of Conservation
           Priorities Based on Ecosystem Services in the Atlantic Forest Region of
           Misiones, Argentina
    • Authors: Andrea E. Izquierdo, Matthew L. Clark
      Pages: 764 - 786
      Abstract: Understanding the spatial pattern of ecosystem services is important for effective environmental policy and decision-making. In this study, we use a geospatial decision-support tool (Marxan) to identify conservation priorities for habitat and a suite of ecosystem services (storage carbon, soil retention and water yield) in the Upper Paraná Atlantic Forest from Misiones, Argentina—an area of global conservation priority. Using these results, we then evaluate the efficiency of existing protected areas in conserving both habitat and ecosystem services. Selected areas for conserving habitat had an overlap of carbon and soil ecosystem services. Yet, selected areas for water yield did not have this overlap. Furthermore, selected areas with relatively high overlap of ecosystem services tended to be inside protected areas; however, other important areas for ecosystem services (i.e., central highlands) do not have legal protection, revealing the importance of enforcing existing environmental regulations in these areas.
      PubDate: 2012-08-27
      DOI: 10.3390/f3030764
      Issue No: Vol. 3, No. 3 (2012)
       
  • Forests, Vol. 3, Pages 787-798: Long-Term Survival of Saplings during the
           Transformation to Continuous Cover
    • Authors: Gary Kerr, Hamish Mackintosh
      Pages: 787 - 798
      Abstract: The Glentress Trial Area is an extensive research area in southern Scotland of 117 ha where a long-term trial of the transformation of even-aged plantations to continuous cover has been in progress since 1952. During the assessment of permanent sample plots in 1990 information on the species and spatial position of saplings (trees taller than 1.3 m with a diameter at breast height of < 7 cm) was recorded. This provided a unique opportunity to investigate the long-term survival of saplings during the transformation process when the Trial Area was reassessed in 2009. The main finding was that 37% of saplings survived the 19-year period and the majority developed into trees (≥7 cm diameter at breast height). There was considerable variation between species, the lowest survival of saplings was European larch (Larix decidua Mill.) (13%) and the highest European beech (Fagus sylvatica L.) (55%); however differences between species were not significant. There were, however, significant differences between the six management areas with three with high sapling survival (55% to 61%) but others much lower (27% to 32%). If this result is confirmed by other studies, covering a broader range of sites, management guidance that assumes 90% survival will need to be revised.
      PubDate: 2012-09-07
      DOI: 10.3390/f3030787
      Issue No: Vol. 3, No. 3 (2012)
       
  • Forests, Vol. 3, Pages 799-817: Habitat Modeling of Alien Plant Species at
           Varying Levels of Occupancy
    • Authors: Dawn Lemke, Jennifer A. Brown
      Pages: 799 - 817
      Abstract: Distribution models of invasive plants are very useful tools for conservation management. There are challenges in modeling expanding populations, especially in a dynamic environment, and when data are limited. In this paper, predictive habitat models were assessed for three invasive plant species, at differing levels of occurrence, using two different habitat modeling techniques: logistic regression and maximum entropy. The influence of disturbance, spatial and temporal heterogeneity, and other landscape characteristics is assessed by creating regional level models based on occurrence records from the USDA Forest Service’s Forest Inventory and Analysis database. Logistic regression and maximum entropy models were assessed independently. Ensemble models were developed to combine the predictions of the two analysis approaches to obtain a more robust prediction estimate. All species had strong models with Area Under the receiver operator Curve (AUC) of >0.75. The species with the highest occurrence, Ligustrum spp., had the greatest agreement between the models (93%). Lolium arundinaceum had the most disagreement between models at 33% and the lowest AUC values. Overall, the strength of integrative modeling in assessing and understanding habitat modeling was demonstrated.
      PubDate: 2012-09-07
      DOI: 10.3390/f3030799
      Issue No: Vol. 3, No. 3 (2012)
       
  • Forests, Vol. 3, Pages 818-839: Allometric Equations for Estimating Carbon
           Stocks in Natural Forest in New Zealand
    • Authors: Peter N. Beets, Mark O. Kimberley, Graeme R. Oliver, Stephen H. Pearce, J. Doug Graham, Andrea Brandon
      Pages: 818 - 839
      Abstract: Species-specific and mixed-species volume and above ground biomass allometric equations were developed for 15 indigenous tree species and four tree fern species in New Zealand. A mixed-species tree equation based on breast height diameter (DBH) and tree height (H) provided acceptable estimates of stem plus branch (>10 cm in diameter over bark) volume, which was multiplied by live tree density to estimate dry matter. For dead standing spars, DBH, estimated original height, actual spar height and compatible volume/taper functions provided estimates of dead stem volume, which was multiplied by live tree density and a density modifier based on log decay class from field assessments to estimate dry matter. Live tree density was estimated using ratio estimators. Ratio estimators were based on biomass sample trees, and utilized density data from outerwood basic density surveys which were available for 35 tree species sampled throughout New Zealand. Foliage and branch ( < 10 cm in diameter over bark) dry matter were estimated directly from tree DBH. Tree fern above ground dry matter was estimated using allometric equations based on DBH and H. Due to insufficient data, below ground carbon for trees was estimated using the default IPCC root/shoot ratio of 25%, but for tree ferns it was estimated using measured root/shoot ratios which averaged 20%.
      PubDate: 2012-09-10
      DOI: 10.3390/f3030818
      Issue No: Vol. 3, No. 3 (2012)
       
  • Forests, Vol. 3, Pages 840-852: Relationship between Invasive Plant
           Species and Forest Fauna in Eastern North America
    • Authors: Stephanie J. Hayes, Eric J. Holzmueller
      Pages: 840 - 852
      Abstract: Invasive plant species have long been known to cause extensive damage, both economically and ecologically, to native ecosystems. They have historically been introduced by the public, both intentional and not, for a variety of reasons. Many of the woody shrubs, such as Lonicera maackii and Rosa multiflora were introduced for wildlife cover, forage, and ornamental value. These invasives have quickly out-competed native flora, in many cases drastically impacting and changing the environment they inhabit. In this review, chosen species characteristics have been described, their pathway to invasion explained, and their impacts to native wildlife highlighted. Based on a review of the scientific literature, we determined that not all effects by invasive plants are negative. Many positive impacts can be seen throughout the literature, such as native frogs utilizing Microstegium vimineum for cover and nesting habitat. However, some important invasive plant species were not included in this review due to a lack of literature on the subject of the effects on fauna. While much is known about their economic impact and the impact on native plant species, additional work needs to be done in the field of wildlife research to determine current impacts and future implications of non-native, invasive plants on native fauna.
      PubDate: 2012-09-12
      DOI: 10.3390/f3030840
      Issue No: Vol. 3, No. 3 (2012)
       
 
 
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