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Forests, Volume 4, Issue 4 (December 2013), Pages 730-1231

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Open AccessArticle Ambiguity in Timber Trade Regarding Efforts to Combat Illegal Logging: Potential Impacts on Trade between South-East Asia and Europe
Forests 2013, 4(4), 730-750; doi:10.3390/f4040730
Received: 8 July 2013 / Revised: 3 September 2013 / Accepted: 12 September 2013 / Published: 25 September 2013
Cited by 7 | PDF Full-text (419 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Spatial Distribution and Volume of Dead Wood in Unmanaged Caspian Beech (Fagus orientalis) Forests from Northern Iran
Forests 2013, 4(4), 751-765; doi:10.3390/f4040751
Received: 4 June 2013 / Revised: 3 September 2013 / Accepted: 4 September 2013 / Published: 26 September 2013
Cited by 4 | PDF Full-text (1658 KB) | HTML Full-text | XML Full-text
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,
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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. Full article
Open AccessArticle Assessing the Potential Stem Growth and Quality of Yellow Birch Prior to Restoration: A Case Study in Eastern Canada
Forests 2013, 4(4), 766-785; doi:10.3390/f4040766
Received: 2 July 2013 / Revised: 17 September 2013 / Accepted: 22 September 2013 / Published: 30 September 2013
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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
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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. Full article
(This article belongs to the Special Issue Forest Restoration and Regeneration)
Open AccessArticle Wood Quality and Growth Characterization across Intra- and Inter-Specific Hybrid Aspen Clones
Forests 2013, 4(4), 786-807; doi:10.3390/f4040786
Received: 24 July 2013 / Revised: 11 September 2013 / Accepted: 17 September 2013 / Published: 30 September 2013
Cited by 6 | PDF Full-text (718 KB) | HTML Full-text | XML Full-text
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.
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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. Full article
(This article belongs to the Special Issue Improving Wood Quality from Planted Forests)
Open AccessCommunication Monitoring Post Disturbance Forest Regeneration with Hierarchical Object-Based Image Analysis
Forests 2013, 4(4), 808-829; doi:10.3390/f4040808
Received: 13 August 2013 / Revised: 12 September 2013 / Accepted: 23 September 2013 / Published: 11 October 2013
Cited by 2 | PDF Full-text (2232 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Are the Economically Optimal Harvesting Strategies of Uneven-Aged Pinus nigra Stands Always Sustainable and Stabilizing?
Forests 2013, 4(4), 830-848; doi:10.3390/f4040830
Received: 26 July 2013 / Revised: 22 September 2013 / Accepted: 30 September 2013 / Published: 18 October 2013
Cited by 2 | PDF Full-text (311 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Influence of Different Tillage Systems and Weed Treatments in the Establishment Year on the Final Biomass Production of Short Rotation Coppice Poplar
Forests 2013, 4(4), 849-867; doi:10.3390/f4040849
Received: 7 August 2013 / Revised: 19 September 2013 / Accepted: 15 October 2013 / Published: 24 October 2013
Cited by 7 | PDF Full-text (773 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Estimation of the Relationship between Urban Park Characteristics and Park Cool Island Intensity by Remote Sensing Data and Field Measurement
Forests 2013, 4(4), 868-886; doi:10.3390/f4040868
Received: 20 July 2013 / Revised: 24 September 2013 / Accepted: 9 October 2013 / Published: 24 October 2013
Cited by 11 | PDF Full-text (755 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Concentration Levels of Imidacloprid and Dinotefuran in Five Tissue Types of Black Walnut, Juglans nigra
Forests 2013, 4(4), 887-897; doi:10.3390/f4040887
Received: 3 July 2013 / Revised: 30 August 2013 / Accepted: 16 October 2013 / Published: 1 November 2013
Cited by 3 | PDF Full-text (370 KB) | HTML Full-text | XML Full-text
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,
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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. Full article
Open AccessArticle A Photogrammetric Workflow for the Creation of a Forest Canopy Height Model from Small Unmanned Aerial System Imagery
Forests 2013, 4(4), 922-944; doi:10.3390/f4040922
Received: 26 September 2013 / Revised: 12 October 2013 / Accepted: 25 October 2013 / Published: 6 November 2013
Cited by 34 | PDF Full-text (6749 KB) | HTML Full-text | XML Full-text | Supplementary Files
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
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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. Full article
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Open AccessArticle Nordic Forest Energy Solutions in the Republic of Karelia
Forests 2013, 4(4), 945-967; doi:10.3390/f4040945
Received: 27 June 2013 / Revised: 21 September 2013 / Accepted: 8 October 2013 / Published: 13 November 2013
Cited by 3 | PDF Full-text (355 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Deforestation and Changes in Landscape Patterns from 1979 to 2006 in Suan County, DPR Korea
Forests 2013, 4(4), 968-983; doi:10.3390/f4040968
Received: 12 August 2013 / Revised: 13 September 2013 / Accepted: 5 November 2013 / Published: 13 November 2013
Cited by 5 | PDF Full-text (2467 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Above-Ground Biomass and Biomass Components Estimation Using LiDAR Data in a Coniferous Forest
Forests 2013, 4(4), 984-1002; doi:10.3390/f4040984
Received: 8 August 2013 / Revised: 28 October 2013 / Accepted: 15 November 2013 / Published: 20 November 2013
Cited by 16 | PDF Full-text (2163 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Allometries for Widely Spaced Populus ssp. and Betula ssp. in Nurse Crop Systems
Forests 2013, 4(4), 1003-1031; doi:10.3390/f4041003
Received: 8 September 2013 / Revised: 6 November 2013 / Accepted: 6 November 2013 / Published: 22 November 2013
Cited by 4 | PDF Full-text (3577 KB) | HTML Full-text | XML Full-text
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
[...] Read more.
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. Full article
Open AccessArticle Potential for Climate Change Mitigation in Degraded Forests: A Study from La Primavera, México
Forests 2013, 4(4), 1032-1054; doi:10.3390/f4041032
Received: 23 September 2013 / Revised: 8 November 2013 / Accepted: 15 November 2013 / Published: 22 November 2013
Cited by 3 | PDF Full-text (689 KB) | HTML Full-text | XML Full-text
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
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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. Full article
(This article belongs to the Special Issue Forest and Wood Vegetation Carbon Stores and Sequestration)
Open AccessArticle Late-Successional and Old-Growth Forests in the Northeastern United States: Structure, Dynamics, and Prospects for Restoration
Forests 2013, 4(4), 1055-1086; doi:10.3390/f4041055
Received: 2 July 2013 / Revised: 9 November 2013 / Accepted: 14 November 2013 / Published: 26 November 2013
Cited by 2 | PDF Full-text (1655 KB) | HTML Full-text | XML Full-text
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
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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. Full article
(This article belongs to the Special Issue Forest Restoration and Regeneration)
Open AccessArticle Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile)
Forests 2013, 4(4), 1087-1105; doi:10.3390/f4041087
Received: 23 July 2013 / Revised: 29 October 2013 / Accepted: 19 November 2013 / Published: 28 November 2013
Cited by 1 | PDF Full-text (443 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Contrasting Hydraulic Strategies during Dry Soil Conditions in Quercus rubra and Acer rubrum in a Sandy Site in Michigan
Forests 2013, 4(4), 1106-1120; doi:10.3390/f4041106
Received: 13 September 2013 / Revised: 4 November 2013 / Accepted: 3 December 2013 / Published: 11 December 2013
Cited by 15 | PDF Full-text (394 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Use of Forest Residues for Building Forest Biomass Supply Chains: Technical and Economic Analysis of the Production Process
Forests 2013, 4(4), 1121-1140; doi:10.3390/f4041121
Received: 5 September 2013 / Revised: 12 November 2013 / Accepted: 3 December 2013 / Published: 11 December 2013
Cited by 6 | PDF Full-text (1437 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle White Spruce Plantations on Abandoned Agricultural Land: Are They More Effective as C Sinks than Natural Succession?
Forests 2013, 4(4), 1141-1157; doi:10.3390/f4041141
Received: 16 October 2013 / Revised: 21 November 2013 / Accepted: 3 December 2013 / Published: 11 December 2013
Cited by 3 | PDF Full-text (726 KB) | HTML Full-text | XML Full-text
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
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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. Full article
(This article belongs to the Special Issue Forest and Wood Vegetation Carbon Stores and Sequestration)
Open AccessArticle Risks, Information and Short-Run Timber Supply
Forests 2013, 4(4), 1158-1170; doi:10.3390/f4041158
Received: 8 October 2013 / Revised: 26 November 2013 / Accepted: 5 December 2013 / Published: 11 December 2013
Cited by 1 | PDF Full-text (474 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle The Impact of Industrial Context on Procurement, Management and Development of Harvesting Services: A Comparison of Two Swedish Forest Owners Associations
Forests 2013, 4(4), 1171-1198; doi:10.3390/f4041171
Received: 12 September 2013 / Revised: 29 November 2013 / Accepted: 5 December 2013 / Published: 11 December 2013
Cited by 3 | PDF Full-text (1393 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessCommunication An Exploratory Assessment of a Smartphone Application for Public Participation in Forest Fuels Measurement in the Wildland-Urban Interface
Forests 2013, 4(4), 1199-1219; doi:10.3390/f4041199
Received: 28 August 2013 / Revised: 26 October 2013 / Accepted: 11 December 2013 / Published: 16 December 2013
Cited by 4 | PDF Full-text (1299 KB) | HTML Full-text | XML Full-text
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
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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. Full article
Open AccessArticle Potentials for Mutually Beneficial Collaboration Between FIA Specialists and IEG-40 Pathologists and Geneticists Working on Fusiform Rust
Forests 2013, 4(4), 1220-1231; doi:10.3390/f4041220
Received: 22 September 2013 / Revised: 11 December 2013 / Accepted: 11 December 2013 / Published: 17 December 2013
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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)
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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. Full article
(This article belongs to the Special Issue Fusiform Rust Disease—Biology and Management of Resistance)

Review

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Open AccessReview Applicability of International Harvesting Equipment Productivity Studies in Maine, USA: A Literature Review
Forests 2013, 4(4), 898-921; doi:10.3390/f4040898
Received: 12 July 2013 / Revised: 14 September 2013 / Accepted: 11 October 2013 / Published: 5 November 2013
Cited by 10 | PDF Full-text (1167 KB) | HTML Full-text | XML Full-text
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
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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. Full article

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