Forests

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Open AccessArticle

The Use of Decision Support Systems in Forest Management: Analysis of FORSYS Country Reports

by Silvana Nobre, Ljusk-Ola Eriksson and Renats Trubins

Forests 2016, 7(3), 72; https://doi.org/10.3390/f7030072 - 21 Mar 2016

Cited by 28 | Viewed by 7379

From 2009 to 2013, a group of more than 100 researchers from 26 countries, under a COST-Action project named FORSYS, worked on a review of the use of forest management decision support systems (FMDSS). Guided by a template, local researchers conducted assessments of [...] Read more.

From 2009 to 2013, a group of more than 100 researchers from 26 countries, under a COST-Action project named FORSYS, worked on a review of the use of forest management decision support systems (FMDSS). Guided by a template, local researchers conducted assessments of FMDSS use in their countries; their results were documented in Country Reports. In this study, we have used the Country Reports to construct a summary of FMDSS use. For the purposes of our analysis, we conducted a two-round categorisation of the main themes to describe the most relevant aspects of FMDSS use. The material produced was used to generate quantitative summaries of (i) the types of problem where FMDSS are used, (ii) models and methods used to solve these problems, (iii) knowledge management techniques, and (iv) participatory planning techniques. Beyond this, a qualitative analysis identified and summarised the local researchers’ primary concerns, recorded in the conclusions to the Country Reports; we designated these “lessons learned”. Results from the quantitative analysis suggested that most of the participant countries were making use of latest generation FMDSS. A few did not have practical problems that justified the use of such technology or they were still at the beginning of the process of building models to solve their own forest problems. Full article

(This article belongs to the Special Issue The 24th IUFRO World Congress: Session 118 Providing Ecosystem Services under Climate Change: Community of Practice of Forest Decision Support Systems)

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2859 KiB

Open AccessArticle

The Urban Environment Can Modify Drought Stress of Small-Leaved Lime (Tilia cordata Mill.) and Black Locust (Robinia pseudoacacia L.)

by Astrid Moser, Thomas Rötzer, Stephan Pauleit and Hans Pretzsch

Forests 2016, 7(3), 71; https://doi.org/10.3390/f7030071 - 17 Mar 2016

Cited by 57 | Viewed by 8500

Abstract

The urban environment characterized by various stresses poses challenges to trees. In particular, water deficits and high temperatures can cause immense drought stress to urban trees, resulting in reduced growth and die-off. Drought-tolerant species are expected to be resilient to these conditions and [...] Read more.

The urban environment characterized by various stresses poses challenges to trees. In particular, water deficits and high temperatures can cause immense drought stress to urban trees, resulting in reduced growth and die-off. Drought-tolerant species are expected to be resilient to these conditions and are therefore advantageous over other, more susceptible species. However, the drought tolerance of urban trees in relation to the specific growth conditions in urban areas remains poorly researched. This study aimed to analyze the annual growth and drought tolerance of two common urban tree species, namely small-leaved lime (Tilia cordata Mill. (T. cordata)) and black locust (Robinia pseudoacacia L. (R. pseudoacacia)), in two cities in southern Germany in relation to their urban growing conditions. Marked growth reductions during drought periods and subsequent fast recovery were found for R. pseudoacacia, whereas T. cordata exhibited continued reduced growth after a drought event, although these results were highly specific to the analyzed city. We further show that individual tree characteristics and environmental conditions significantly influence the growth of urban trees. Canopy openness and other aspects of the surrounding environment (water supply and open surface area of the tree pit), tree size, and tree species significantly affect urban tree growth and can modify the ability of trees to tolerate the drought stress in urban areas. Sustainable tree planting of well adapted tree species to their urban environment ensures healthy trees providing ecosystem services for a high quality of life in cities. Full article

(This article belongs to the Special Issue Urban and Periurban Forest Diversity and Ecosystem Services)

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Open AccessArticle

Geospatial Estimation of above Ground Forest Biomass in the Sierra Madre Occidental in the State of Durango, Mexico

by Pablito M. López-Serrano, Carlos A. López Sánchez, Raúl Solís-Moreno and José J. Corral-Rivas

Forests 2016, 7(3), 70; https://doi.org/10.3390/f7030070 - 15 Mar 2016

Cited by 19 | Viewed by 6080

Abstract

Combined use of new geospatial techniques and non-parametric multivariate statistical methods enables monitoring and quantification of the biomass of large areas of forest ecosystems with acceptable reliability. The main objective of the present study was to estimate the aboveground forest biomass (AGB) in [...] Read more.

Combined use of new geospatial techniques and non-parametric multivariate statistical methods enables monitoring and quantification of the biomass of large areas of forest ecosystems with acceptable reliability. The main objective of the present study was to estimate the aboveground forest biomass (AGB) in the Sierra Madre Occidental (SMO) in the state of Durango, Mexico, using the M5 model tree (M5P) technique and the analysis of medium-resolution satellite-based multi-spectral data, and field data collected from a network of 201 permanent forest growth and soil research sites (SPIFyS). Research plots were installed by systematic sampling throughout the study area in 2011. The digital levels of the images were converted to apparent reflectance (ToA) and surface reflectance (SR). The M5P technique that constructs tree-based piecewise linear models was used. The fitted model with SR and tree abundance by species group as predictive variables (ASG) explained 73% of the observed AGB variance (the root mean squared error (RMSE) = 39.40 Mg·ha⁻¹). The variables that best discriminated the AGB, in order of decreasing importance, were the normalized difference vegetation index (NDVI), tree abundance of other broadleaves species (OB), Band 4 of Landsat 5 TM (Thematic Mapper) satellite and tree abundance of pines (Pinus). The results demonstrate the potential usefulness of the M5P method for estimating AGB based in the surface reflectance values (SR). Full article

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Open AccessArticle

Effect of Organic Layer Thickness on Black Spruce Aging Mistakes in Canadian Boreal Forests

by Ahmed Laamrani, Annie DesRochers and Line Blackburn

Forests 2016, 7(3), 69; https://doi.org/10.3390/f7030069 - 15 Mar 2016

Cited by 3 | Viewed by 5070

Abstract

Boreal black spruce (Picea mariana) forests are prone to developing thick organic layers (paludification). Black spruce is adapted to this environment by the continuous development of adventitious roots, masking the root collar and making it difficult to age trees. Ring counts [...] Read more.

Boreal black spruce (Picea mariana) forests are prone to developing thick organic layers (paludification). Black spruce is adapted to this environment by the continuous development of adventitious roots, masking the root collar and making it difficult to age trees. Ring counts above the root collar underestimate age of trees, but the magnitude of age underestimation of trees in relation to organic layer thickness (OLT) is unknown. This age underestimation is required to produce appropriate age-correction tools to be used in land resource management. The goal of this study was to assess aging errors that are done with standard ring counts of trees growing in sites with different degrees of paludification (OLT; 0–25 cm, 26–65 cm, >65 cm). Age of 81 trees sampled at three geographical locations was determined by ring counts at ground level and at 1 m height, and real age of trees was determined by cross-dating growth rings down to the root collar (root/shoot interface). Ring counts at 1 m height underestimated age of trees by a mean of 22 years (range 13–49) and 52 years (range 14–112) in null to low vs. moderately to highly paludified stands, respectively. The percentage of aging-error explained by our linear model was relatively high (R²_adj = 0.71) and showed that OLT class and age at 0-m could be used to predict total aging-error while neither DBH nor geographic location could. The resulting model has important implications for forest management to accurately estimate productivity of these forests. Full article

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Open AccessCommunication

Forest Management Challenges for Sustaining Water Resources in the Anthropocene

by Ge Sun and James M. Vose

Forests 2016, 7(3), 68; https://doi.org/10.3390/f7030068 - 15 Mar 2016

Cited by 41 | Viewed by 7672

Abstract

The Earth has entered the Anthropocene epoch that is dominated by humans who demand unprecedented quantities of goods and services from forests. The science of forest hydrology and watershed management generated during the past century provides a basic understanding of relationships among forests [...] Read more.

The Earth has entered the Anthropocene epoch that is dominated by humans who demand unprecedented quantities of goods and services from forests. The science of forest hydrology and watershed management generated during the past century provides a basic understanding of relationships among forests and water and offers management principles that maximize the benefits of forests for people while sustaining watershed ecosystems. However, the rapid pace of changes in climate, disturbance regimes, invasive species, human population growth, and land use expected in the 21st century is likely to create substantial challenges for watershed management that may require new approaches, models, and best management practices. These challenges are likely to be complex and large scale, involving a combination of direct and indirect biophysical watershed responses, as well as socioeconomic impacts and feedbacks. We discuss the complex relationships between forests and water in a rapidly changing environment, examine the trade-offs and conflicts between water and other resources, and propose new management approaches for sustaining water resources in the Anthropocene. Full article

(This article belongs to the Special Issue Forest Management and Water Resources in the Anthropocene)

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Open AccessArticle

Short-Term vs. Long-Term Effects of Understory Removal on Nitrogen and Mobile Carbohydrates in Overstory Trees

by Zhong Du, Xiaohu Cai, Weikai Bao, Huai Chen, Hongli Pan, Xue Wang, Qingxia Zhao, Wanze Zhu, Xingliang Liu, Yong Jiang and Mai-He Li

Forests 2016, 7(3), 67; https://doi.org/10.3390/f7030067 - 14 Mar 2016

Cited by 8 | Viewed by 9891

Abstract

Understory management in forest ecosystems has been applied to improve the wood production for hundreds of years worldwide. The carbon-physiological mechanisms underlying these positive effects of understory management on the growth of overstory trees have received less attention. We studied the non-structural carbohydrate [...] Read more.

Understory management in forest ecosystems has been applied to improve the wood production for hundreds of years worldwide. The carbon-physiological mechanisms underlying these positive effects of understory management on the growth of overstory trees have received less attention. We studied the non-structural carbohydrate (NSC) and total nitrogen (N) concentrations in tissues (needles, stem sapwood, and fine roots) of three tree species (two evergreen and one deciduous species) grown in the presence or absence (understory cut) of understory shrubs in plantations in southwestern China, to test whether understories affect the carbon and nitrogen status in the overstory trees. The concentrations of N, NSC (= soluble sugars + starch) in overstory trees varied significantly with understory treatments during the dry season rather than the wet season. Trees grown without understory shrubs had higher levels of N and NSC compared to trees grown with understories. The present study provides insight to explain the functional mechanisms for understory effects on growth of overstory trees, and indicates that the nitrogen and carbon status in overstory trees may be more strongly negatively affected by understory in stressful conditions rather than in optimal growth conditions. Moreover, the present study provides ecophysiology-based knowledge for dealing with understory vegetation management in forest ecosystems. Full article

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Open AccessArticle

Decreasing Deforestation in the Southern Brazilian Amazon—The Role of Administrative Sanctions in Mato Grosso State

by Paulo Queiroz Sousa

Forests 2016, 7(3), 66; https://doi.org/10.3390/f7030066 - 12 Mar 2016

Cited by 13 | Viewed by 10278

Abstract

Forest conservation efforts through regulatory enforcement routinely failed to prevent large scale deforestation in the Brazilian Amazon. However, a turning point occurred in 2005, when a combination of unfavorable economic conditions and an unprecedented coordinated effort between governmental institutions resulted in a gradual [...] Read more.

Forest conservation efforts through regulatory enforcement routinely failed to prevent large scale deforestation in the Brazilian Amazon. However, a turning point occurred in 2005, when a combination of unfavorable economic conditions and an unprecedented coordinated effort between governmental institutions resulted in a gradual slowdown in deforestation. The continuation of this deforestation slowdown in an environment of economic recovery and expansion after 2009 suggests that regulatory enforcement achieved a measure of success not experienced before. In this study, the impact of fines, embargoes on rural private properties, and confiscation of means of production and produce on deforestation in the Southern Amazon state of Mato Grosso was considered through regression and GIS-based analyses. It was found that while all three sanctions were negatively correlated with deforestation, there were important differences in their level of enforcement. Embargoes were effectively implemented and showed high deforestation deterrence effectiveness, but the actual collection of the values of fines issued was extremely low, which casts doubts on their actual effectiveness as a deforestation deterrence mechanism. The results suggest that while sanctions for illegal deforestation have played an important role in the slowdown in deforestation, measures to increase the collection of fines issued are urgently needed. Full article

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Open AccessArticle

Tree Mortality Undercuts Ability of Tree-Planting Programs to Provide Benefits: Results of a Three-City Study

by Sarah Widney, Burnell C. Fischer and Jess Vogt

Forests 2016, 7(3), 65; https://doi.org/10.3390/f7030065 - 11 Mar 2016

Cited by 40 | Viewed by 9961

Abstract

Trees provide numerous benefits for urban residents, including reduced energy usage, improved air quality, stormwater management, carbon sequestration, and increased property values. Quantifying these benefits can help justify the costs of planting trees. In this paper, we use i-Tree Streets to quantify the [...] Read more.

Trees provide numerous benefits for urban residents, including reduced energy usage, improved air quality, stormwater management, carbon sequestration, and increased property values. Quantifying these benefits can help justify the costs of planting trees. In this paper, we use i-Tree Streets to quantify the benefits of street trees planted by nonprofits in three U.S. cities (Detroit, Michigan; Indianapolis, Indiana, and Philadelphia, Pennsylvania) from 2009 to 2011. We also use both measured and modeled survival and growth rates to “grow” the tree populations 5 and 10 years into the future to project the future benefits of the trees under different survival and growth scenarios. The 4059 re-inventoried trees (2864 of which are living) currently provide almost $40,000 (USD) in estimated annual benefits ($9–$20/tree depending on the city), the majority (75%) of which are increased property values. The trees can be expected to provide increasing annual benefits during the 10 years after planting if the annual survival rate is higher than the 93% annual survival measured during the establishment period. However, our projections show that with continued 93% or lower annual survival, the increase in annual benefits from tree growth will not be able to make up for the loss of benefits as trees die. This means that estimated total annual benefits from a cohort of planted trees will decrease between the 5-year projection and the 10-year projection. The results of this study indicate that without early intervention to ensure survival of planted street trees, tree mortality may be significantly undercutting the ability of tree-planting programs to provide benefits to neighborhood residents. Full article

(This article belongs to the Special Issue Urban and Periurban Forest Diversity and Ecosystem Services)

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Open AccessArticle

Edge Influence on Diversity of Orchids in Andean Cloud Forests

by Edicson Parra Sánchez, Dolors Armenteras and Javier Retana

Forests 2016, 7(3), 63; https://doi.org/10.3390/f7030063 - 11 Mar 2016

Cited by 22 | Viewed by 5945

Abstract

Cloud forests harbor high levels of orchid diversity. However, due to the high fragmentation of these forests in the Andes, combined with the pressure for new agricultural land, orchid diversity is highly threatened. Despite this worrying scenario, few studies have assessed the effects [...] Read more.

Cloud forests harbor high levels of orchid diversity. However, due to the high fragmentation of these forests in the Andes, combined with the pressure for new agricultural land, orchid diversity is highly threatened. Despite this worrying scenario, few studies have assessed the effects of habitat loss specifically on orchid assemblages in the Andes. The aim of this study was to analyze the edge effect on orchids in cloud forest fragments of varying size. We measured forest structure, neighboring land cover and edge effect on orchid abundance, species richness and beta-diversity, by sampling assemblages along edge-to-interior transects in six different sized Andean (southwest Colombia) forest remnants. We recorded 11,127 stem-individuals of orchids in 141 species. Within the forest, edges sustained equal or more species than interior plots. Our results revealed neither patch metrics nor forest structure showed any significant association to orchid diversity at any scale. Nonetheless, from our observations in composition, the type of neighboring cover, particularly pastures, negatively influences interior species (richness and composition) in larger reserves. This might be due to the fact that some species found in interior plots tend to be confined, with sporadic appearances in regeneration forest and are very scarce or absent in pastures. Species richness differed significantly between matrix types. Our results suggest that (1) orchid diversity shows spatial variability in response to disturbances, but the response is independent from forest structure, patch size and patch geometry; (2) orchid communities are negatively affected by covers, and this pattern is reflected in reduced richness and high species turnover; (3) orchid richness edge effect across a pasture-interior gradient. Two forest management implications can be discerned from our results: (1) management strategies aiming to reduce edge effects may focus on improvement regeneration conditions around pasture lands; and (2) local scale management and conservation activities of natural forests in cloud forests will favor small reserves that harbor high levels of richness. Full article

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Open AccessArticle

Application of Wildfire Risk Assessment Results to Wildfire Response Planning in the Southern Sierra Nevada, California, USA

by Matthew P. Thompson, Phil Bowden, April Brough, Joe H. Scott, Julie Gilbertson-Day, Alan Taylor, Jennifer Anderson and Jessica R. Haas

Forests 2016, 7(3), 64; https://doi.org/10.3390/f7030064 - 10 Mar 2016

Cited by 79 | Viewed by 9437

Abstract

How wildfires are managed is a key determinant of long-term socioecological resiliency and the ability to live with fire. Safe and effective response to fire requires effective pre-fire planning, which is the main focus of this paper. We review general principles of effective [...] Read more.

How wildfires are managed is a key determinant of long-term socioecological resiliency and the ability to live with fire. Safe and effective response to fire requires effective pre-fire planning, which is the main focus of this paper. We review general principles of effective federal fire management planning in the U.S., and introduce a framework for incident response planning consistent with these principles. We contextualize this framework in relation to a wildland fire management continuum based on federal fire management policy in the U.S. The framework leverages recent advancements in spatial wildfire risk assessment—notably the joint concepts of in situ risk and source risk—and integrates assessment results with additional geospatial information to develop and map strategic response zones. We operationalize this framework in a geographic information system (GIS) environment based on landscape attributes relevant to fire operations, and define Potential wildland fire Operational Delineations (PODs) as the spatial unit of analysis for strategic response. Using results from a recent risk assessment performed on several National Forests in the Southern Sierra Nevada area of California, USA, we illustrate how POD-level summaries of risk metrics can reduce uncertainty surrounding potential losses and benefits given large fire occurrence, and lend themselves naturally to design of fire and fuel management strategies. To conclude we identify gaps, limitations, and uncertainties, and prioritize future work to support safe and effective incident response. Full article

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Open AccessArticle

Estimation of Tree Stem Attributes Using Terrestrial Photogrammetry with a Camera Rig

by Mona Forsman, Niclas Börlin and Johan Holmgren

Forests 2016, 7(3), 61; https://doi.org/10.3390/f7030061 - 08 Mar 2016

Cited by 70 | Viewed by 11224

Abstract

We propose a novel photogrammetric method for field plot inventory, designed for simplicity and time efficiency on-site. A prototype multi-camera rig was used to acquire images from field plot centers in multiple directions. The acquisition time on-site was less than two minutes. From [...] Read more.

We propose a novel photogrammetric method for field plot inventory, designed for simplicity and time efficiency on-site. A prototype multi-camera rig was used to acquire images from field plot centers in multiple directions. The acquisition time on-site was less than two minutes. From each view, a point cloud was generated using a novel, rig-based matching of detected SIFT keypoints. Stems were detected in the merged point cloud, and their positions and diameters were estimated. The method was evaluated on 25 hemi-boreal forest plots of a 10-m radius. Due to difficult lighting conditions and faulty hardware, imagery from only six field plots was processed. The method performed best on three plots with clearly visible stems with a 76% detection rate and 0% commission. Diameters could be estimated for 40% of the stems with an RMSE of 2.8–9.5 cm. The results are comparable to other camera-based methods evaluated in a similar manner. The results are inferior to TLS-based methods. However, our method is easily extended to multiple station image schemas, something that could significantly improve the results while retaining low commission errors and time on-site. Furthermore, with smaller hardware, we believe this could be a useful technique for measuring stem attributes in the forest. Full article

(This article belongs to the Special Issue Forest Ground Observations through Terrestrial Point Clouds)

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Graphical abstract

4623 KiB

Open AccessReview

Managing Forests for Water in the Anthropocene—The Best Kept Secret Services of Forest Ecosystems

by Irena F. Creed, Marian Weber, Francesco Accatino and David P. Kreutzweiser

Forests 2016, 7(3), 60; https://doi.org/10.3390/f7030060 - 08 Mar 2016

Cited by 24 | Viewed by 9004

Abstract

Water and forests are inextricably linked. Pressures on forests from population growth and climate change are increasing risks to forests and their aquatic ecosystem services (AES). There is a need to incorporate AES in forest management but there is considerable uncertainty about how [...] Read more.

Water and forests are inextricably linked. Pressures on forests from population growth and climate change are increasing risks to forests and their aquatic ecosystem services (AES). There is a need to incorporate AES in forest management but there is considerable uncertainty about how to do so. Approaches that manage forest ecosystem services such as fiber, water and carbon sequestration independently ignore the inherent complexities of ecosystem services and their responses to management actions, with the potential for unintended consequences that are difficult to predict. The ISO 31000 Risk Management Standard is a standardized framework to assess risks to forest AES and to prioritize management strategies to manage risks within tolerable ranges. The framework consists of five steps: establishing the management context, identifying, analyzing, evaluating and treating the risks. Challenges to implementing the framework include the need for novel models and indicators to assess forest change and resilience, quantification of linkages between forest practice and AES, and the need for an integrated systems approach to assess cumulative effects and stressors on forest ecosystems and AES. In the face of recent international agreements to protect forests, there are emerging opportunities for international leadership to address these challenges in order to protect both forests and AES. Full article

(This article belongs to the Special Issue Forest Management and Water Resources in the Anthropocene)

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Open AccessArticle

Assessment of Forest Structure Using Two UAV Techniques: A Comparison of Airborne Laser Scanning and Structure from Motion (SfM) Point Clouds

by Luke Wallace, Arko Lucieer, Zbyněk Malenovský, Darren Turner and Petr Vopěnka

Forests 2016, 7(3), 62; https://doi.org/10.3390/f7030062 - 07 Mar 2016

Cited by 488 | Viewed by 28438

Abstract

This study investigates the potential of unmanned aerial vehicles (UAVs) to measure and monitor structural properties of forests. Two remote sensing techniques, airborne laser scanning (ALS) and structure from motion (SfM) were tested to capture three-dimensional structural information from a small multi-rotor UAV [...] Read more.

This study investigates the potential of unmanned aerial vehicles (UAVs) to measure and monitor structural properties of forests. Two remote sensing techniques, airborne laser scanning (ALS) and structure from motion (SfM) were tested to capture three-dimensional structural information from a small multi-rotor UAV platform. A case study is presented through the analysis of data collected from a 30 × 50 m plot in a dry sclerophyll eucalypt forest with a spatially varying canopy cover. The study provides an insight into the capabilities of both technologies for assessing absolute terrain height, the horizontal and vertical distribution of forest canopy elements, and information related to individual trees. Results indicate that both techniques are capable of providing information that can be used to describe the terrain surface and canopy properties in areas of relatively low canopy closure. However, the SfM photogrammetric technique underperformed ALS in capturing the terrain surface under increasingly denser canopy cover, resulting in point density of less than 1 ground point per m² and mean difference from ALS terrain surface of 0.12 m. This shortcoming caused errors that were propagated into the estimation of canopy properties, including the individual tree height (root mean square error of 0.92 m for ALS and 1.30 m for SfM). Differences were also seen in the estimates of canopy cover derived from the SfM (50%) and ALS (63%) pointclouds. Although ALS is capable of providing more accurate estimates of the vertical structure of forests across the larger range of canopy densities found in this study, SfM was still found to be an adequate low-cost alternative for surveying of forest stands. Full article

(This article belongs to the Special Issue Forest Ground Observations through Terrestrial Point Clouds)

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Open AccessArticle

Variation of Drying Strains between Tangential and Radial Directions in Asian White Birch

by Zongying Fu, Jingyao Zhao, Yeli Yang and Yingchun Cai

Forests 2016, 7(3), 59; https://doi.org/10.3390/f7030059 - 07 Mar 2016

Cited by 12 | Viewed by 4935

Abstract

In this study, wood disks of 30 mm in thickness cut from white birch (Betula platyphylla Suk) logs were dried at a constant temperature (40 °C). The drying strains including practical shrinkage strain, elastic strain, viscoelastic creep strain and mechano-sorptive creep were [...] Read more.

In this study, wood disks of 30 mm in thickness cut from white birch (Betula platyphylla Suk) logs were dried at a constant temperature (40 °C). The drying strains including practical shrinkage strain, elastic strain, viscoelastic creep strain and mechano-sorptive creep were measured both tangentially and radially. The effects of moisture content and radial position on each strain were also discussed qualitatively. Overall, the difference of the practical shrinkage strain between the tangential and radial directions was proportional to the distance from the pith. The tangential elastic strain and viscoelastic creep strain were higher than these strains in a radial direction, and they all decreased with the decrease of moisture content. Additionally, there were opposite mechano-sorptive creep between tangential and radial directions. Full article

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Open AccessArticle

Fuel Classes in Conifer Forests of Southwest Sichuan, China, and Their Implications for Fire Susceptibility

by San Wang and Shukui Niu

Forests 2016, 7(3), 52; https://doi.org/10.3390/f7030052 - 07 Mar 2016

Cited by 7 | Viewed by 4991

Abstract

The fuel characteristics that influence the initiation and spread of wildfires were measured in Keteleeria fortune forest (FT1), Pinus yunnanensis forest (FT2), P. yunnanensis and Platycladus orientalis (L.) Franco mixed forest (FT3), P. yunnanensis Franch and K. fortunei (Murr.) Carr mixed forest (FT4), [...] Read more.

The fuel characteristics that influence the initiation and spread of wildfires were measured in Keteleeria fortune forest (FT1), Pinus yunnanensis forest (FT2), P. yunnanensis and Platycladus orientalis (L.) Franco mixed forest (FT3), P. yunnanensis Franch and K. fortunei (Murr.) Carr mixed forest (FT4), Tsuga chinensis forest (FT5), and P. orientalis forest (FT6) in southwest Sichuan Province, China. We compared vertical distributions of four fuel classes (active fuel, fine fuel, medium fuel and thick fuel) in the same vertical strata and in different spatial layers, and analyzed the fire potential (surface fire, passive and active crown fires) of the six forest types (FT). We then classified the six forest types into different groups depending on their wildfire potential. By using the pattern of forest wildfire types that burnt the most number of forests, we identified four fire susceptibility groups. The first two groups had the lowest susceptibility of active crown fires but they differed in the proportion of surface and passive crown fires. The third group was positioned in the middle between types with low and extremely high fire susceptibility; while the fourth group had the highest susceptibility of active crown fires. The results of this study will not only contribute to the prediction of fire behavior, but also will be invaluable for use in forestry management. Full article

(This article belongs to the Special Issue Fire Regimes: Spatial and Temporal Variability and Their Effects on Forests)

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Open AccessArticle

Calorific Value and Chemical Composition of Five Semi-Arid Mexican Tree Species

by Maginot Ngangyo-Heya, Rahim Foroughbahchk-Pournavab, Artemio Carrillo-Parra, José Guadalupe Rutiaga-Quiñones, Volker Zelinski and Luis Fernando Pintor-Ibarra

Forests 2016, 7(3), 58; https://doi.org/10.3390/f7030058 - 04 Mar 2016

Cited by 25 | Viewed by 7336

Abstract

The current global energy crisis has generated growing interest in looking for alternatives to traditional fossil fuels, presenting lignocellulosic materials as a promising resource for sustainable energy production. In this paper, the calorific values and chemical composition of the trunks, branches, twigs and [...] Read more.

The current global energy crisis has generated growing interest in looking for alternatives to traditional fossil fuels, presenting lignocellulosic materials as a promising resource for sustainable energy production. In this paper, the calorific values and chemical composition of the trunks, branches, twigs and leaves of five timber species of the semi-arid land of Mexico (Helietta parvifolia (Gray) Benth., Ebenopsis ebano (Berl.) Barneby, Acacia berlandieri (Benth.), Havardia pallens (Benth.) Britton & Rose and Acacia wrightii (Benth.)) were determined according to international standards. The results highlighted the calorific value ranges of 17.56 to 18.61 MJ kg⁻¹ in trunks, 17.15 to 18.45 MJ kg⁻¹ in branches, 17.29 to 17.92 MJ kg⁻¹ in twigs, and 17.35to 19.36 MJ kg⁻¹ in leaves. The pH presented an acidic trend (3.95–5.64). The content of mineral elements varied in trunks (1.09%–2.29%), branches (0.86%–2.75%), twigs (4.26%–6.76%) and leaves (5.77%–11.79%), showing the higher proportion in Ca (57.03%–95.53%), followed by K (0.95%–19.21%) and Mg (0.88%–13.47%). The highest amount of extractives was obtained in the methanolic solvent (3.96%–17.03%). The lignin recorded values of 28.78%–35.84% for trunks, 17.14%–31.39% for branches and 20.61%–29.92% for twigs. Lignin showed a moderately strong correlation (r = 0.66) with calorific value, but the best mathematical model was registered with the calorific value depending on the pH and lignin (R² = 58.86%). Full article

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Open AccessArticle

Spatial Variation in Tree Density and Estimated Aboveground Carbon Stocks in Southern Africa

by Lulseged Tamene, Powell Mponela, Gudeta W. Sileshi, Jiehua Chen and Jérôme E. Tondoh

Forests 2016, 7(3), 57; https://doi.org/10.3390/f7030057 - 04 Mar 2016

Cited by 4 | Viewed by 5653

Abstract

Variability in woody plant species, vegetation assemblages and anthropogenic activities derails the efforts to have common approaches for estimating biomass and carbon stocks in Africa. In order to suggest management options, it is important to understand the vegetation dynamics and the major drivers [...] Read more.

Variability in woody plant species, vegetation assemblages and anthropogenic activities derails the efforts to have common approaches for estimating biomass and carbon stocks in Africa. In order to suggest management options, it is important to understand the vegetation dynamics and the major drivers governing the observed conditions. This study uses data from 29 sentinel landscapes (4640 plots) across the southern Africa. We used T-Square distance method to sample trees. Allometric models were used to estimate aboveground tree biomass from which aboveground biomass carbon stock (AGBCS) was derived for each site. Results show average tree density of 502 trees·ha⁻¹ with semi-arid areas having the highest (682 trees·ha⁻¹) and arid regions the lowest (393 trees·ha⁻¹). The overall AGBCS was 56.4 Mg·ha⁻¹. However, significant site to site variability existed across the region. Over 60 fold differences were noted between the lowest AGBCS (2.2 Mg·ha⁻¹) in the Musungwa plains of Zambia and the highest (138.1 Mg·ha⁻¹) in the scrublands of Kenilworth in Zimbabwe. Semi-arid and humid sites had higher carbon stocks than sites in sub-humid and arid regions. Anthropogenic activities also influenced the observed carbon stocks. Repeated measurements would reveal future trends in tree cover and carbon stocks across different systems. Full article

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1977 KiB

Open AccessReview

A Review of the Characteristics of Small-Leaved Lime (Tilia cordata Mill.) and Their Implications for Silviculture in a Changing Climate

by Tanguy De Jaegere, Sebastian Hein and Hugues Claessens

Forests 2016, 7(3), 56; https://doi.org/10.3390/f7030056 - 01 Mar 2016

Cited by 57 | Viewed by 11128

Abstract

Tilia cordata Mill. is a minor European broadleaved species with a wide but scattered distribution. Given its scarcity and low value in the wood market, it has received little attention from researchers and forest managers. This review summarizes the main aspects of T. [...] Read more.

Tilia cordata Mill. is a minor European broadleaved species with a wide but scattered distribution. Given its scarcity and low value in the wood market, it has received little attention from researchers and forest managers. This review summarizes the main aspects of T. cordata ecology and growth. Its main limiting factor is its need for warm summer temperatures to ensure successful seed production. It has a height growth pattern relatively similar to that of Acer pseudoplatanus L., with a slight delay in the early stages. Yield tables report great productivity, especially in eastern Europe. T. cordata used to be a major species in Europe, in contrast to its present distribution, but it is very likely to receive renewed interest in the future. Indeed, with the potential change of competition between species in some regions and the need for important diversification in others, T. cordata may play an important role in forest adaptation to climate change, especially owing to its wide ecological tolerance and its numerous ecosystem services. It is necessary to increase our knowledge about its regeneration and its responses to environmental and silvicultural factors, to establish clear management recommendations. Full article

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7410 KiB

Open AccessArticle

Tropical Forest Gain and Interactions amongst Agents of Forest Change

by Sean Sloan

Forests 2016, 7(3), 55; https://doi.org/10.3390/f7030055 - 27 Feb 2016

Cited by 17 | Viewed by 6846

Abstract

The tropical deforestation literature advocates multi-agent enquiry in recognition that key dynamics arise from inter-agent interactions. Studies of tropical forest-cover gain have lagged in this respect. This article explores the roles and key aspects of interactions shaping natural forest regeneration and active reforestation [...] Read more.

The tropical deforestation literature advocates multi-agent enquiry in recognition that key dynamics arise from inter-agent interactions. Studies of tropical forest-cover gain have lagged in this respect. This article explores the roles and key aspects of interactions shaping natural forest regeneration and active reforestation in Eastern Panama since 1990. It employs household surveys of agricultural landholders, interviews with community forest-restoration organisations, archival analysis of plantation reforestation interests, satellite image analysis of forest-cover change, and the consideration of State reforestation policies. Forest-cover gain reflected a convergence of interests and land-use trends amongst agents. Low social and economic costs of sustained interaction and organisation enabled extensive forest-cover gain, but low transaction costs did not. Corporate plantation reforestation rose to the fore of regional forest-cover gain via opportunistic land sales by ranchers and economic subsidies indicative of a State preference for autonomous, self-organising forest-cover gain. This reforestation follows a recent history of neoliberal frontier development in which State-backed loggers and ranchers similarly displaced agriculturalists. Community institutions, long neglected by the State, struggled to coordinate landholders and so effected far less forest-cover gain. National and international commitments to tropical forest restoration risk being similarly characterised as ineffective by a predominance of industrial plantation reforestation without greater State support for community forest management. Full article

(This article belongs to the Special Issue Incentives and Constraints of Community and Smallholder Forestry)

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4426 KiB

Open AccessReview

Complex Challenges of Maintaining Whitebark Pine in Greater Yellowstone under Climate Change: A Call for Innovative Research, Management, and Policy Approaches

by Andrew Hansen, Kathryn Ireland, Kristin Legg, Robert Keane, Edward Barge, Martha Jenkins and Michiel Pillet

Forests 2016, 7(3), 54; https://doi.org/10.3390/f7030054 - 27 Feb 2016

Cited by 24 | Viewed by 8342

Abstract

Climate suitability is projected to decline for many subalpine species, raising questions about managing species under a deteriorating climate. Whitebark pine (WBP) (Pinus albicaulis) in the Greater Yellowstone Ecosystem (GYE) crystalizes the challenges that natural resource managers of many high mountain [...] Read more.

Climate suitability is projected to decline for many subalpine species, raising questions about managing species under a deteriorating climate. Whitebark pine (WBP) (Pinus albicaulis) in the Greater Yellowstone Ecosystem (GYE) crystalizes the challenges that natural resource managers of many high mountain ecosystems will likely face in the coming decades. We review the system of interactions among climate, competitors, fire, bark beetles, white pine blister rust (Cronartium ribicola), and seed dispersers that make WBP especially vulnerable to climate change. A well-formulated interagency management strategy has been developed for WBP, but it has only been implemented across <1% of the species GYE range. The challenges of complex climate effects and land allocation constraints on WBP management raises questions regarding the efficacy of restoration efforts for WBP in GYE. We evaluate six ecological mechanisms by which WBP may remain viable under climate change: climate microrefugia, climate tolerances, release from competition, favorable fire regimes, seed production prior to beetle-induced mortality, and blister-rust resistant trees. These mechanisms suggest that WBP viability may be higher than previously expected under climate change. Additional research is warranted on these mechanisms, which may provide a basis for increased management effectiveness. This review is used as a basis for deriving recommendations for other subalpine species threatened by climate change. Full article

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10233 KiB

Open AccessArticle

Anthropogenic Decline of Ecosystem Services Threatens the Integrity of the Unique Hyrcanian (Caspian) Forests in Northern Iran

by Ardavan Zarandian, Himlal Baral, Ahmad R. Yavari, Hamid R. Jafari, Nigel E. Stork, Matthew A. Ling and Hamid Amirnejad

Forests 2016, 7(3), 51; https://doi.org/10.3390/f7030051 - 27 Feb 2016

Cited by 38 | Viewed by 7641

Abstract

The unique Hyrcanian (Caspian) forests of northern Iran provide vital ecosystem services for local and global communities. We assess the status and trends of key ecosystem services in this region where native forest conversion has accelerated to make way for housing and farm [...] Read more.

The unique Hyrcanian (Caspian) forests of northern Iran provide vital ecosystem services for local and global communities. We assess the status and trends of key ecosystem services in this region where native forest conversion has accelerated to make way for housing and farm development. This is a mountainous forested area that is valuable for both conservation and multiple human uses including recreation and farming. It contains globally significant natural habitats for in situ conservation of biological diversity. A rapid, qualitative, and participatory approach was used including interviews with local households and experts in combination with assessment of land use/cover remote sensing data to identify and map priority ecosystem services in the Geographic Information System (GIS). Based on the interests of the beneficiaries, eight priority services (food production, water supply, raw materials, soil conservation, water regulation, climate regulation, biodiversity, and recreation) were identified and mapped. The results indicate the current typical spatial distribution of the provided services based on structural characteristics of the study landscape and their changing trends through a comparison of past, present and future land use, and land cover. Although food production and recreation have greatly increased in recent decades, the other services, in particular timber production, biodiversity, and water purification and supply are being gradually lost. The results of this study and of others elsewhere should raise awareness of ecosystem service status and trends and the value of examining these since they provide much of the information to inform natural resources policy and decision making. The declines in supply of key ecosystem services both within and outside the protected area are creating conflicts within communities as well as impacting on the integrity of the area and careful planning and conservation is required to provide win-win opportunities. Full article

(This article belongs to the Special Issue Ecosystem Services from Forests)

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611 KiB

Open AccessCorrection

Correction: DellaSala, D.A., et al. Building on Two Decades of Ecosystem Management and Biodiversity Conservation under the Northwest Forest Plan, USA. Forests, 2015, 6, 3326

by Dominick A. DellaSala, Rowan Baker, Doug Heiken, Chris A. Frissell, James R. Karr, S. Kim Nelson, Barry R. Noon, David Olson and James Strittholt

Forests 2016, 7(3), 53; https://doi.org/10.3390/f7030053 - 26 Feb 2016

Viewed by 3882

Abstract

We discovered two typos and a change in a sentence needed in our published manuscript.[...] Full article

(This article belongs to the Special Issue Biodiversity and Conservation in Forests)

2183 KiB

Open AccessArticle

The Effects of Poplar Plantations on Vascular Plant Diversity in Riparian Landscapes

by Jorge Martín-García, Hervé Jactel, Juan Andrés Oria-de-Rueda and Julio Javier Diez

Forests 2016, 7(3), 50; https://doi.org/10.3390/f7030050 - 25 Feb 2016

Cited by 8 | Viewed by 5960

Abstract

Riparian vegetation, which performs many key ecological functions, has been modified or lost at an alarming rate during the past century as a result of human activity. The aims of this study are (a) to investigate the effects of poplar plantations on plant [...] Read more.

Riparian vegetation, which performs many key ecological functions, has been modified or lost at an alarming rate during the past century as a result of human activity. The aims of this study are (a) to investigate the effects of poplar plantations on plant diversity in riparian zones; and (b) to estimate the ecological implications of extending cover by poplar plantations. For this purpose, we assessed species richness, habitat indicator species and functional diversity based on Grime’s C-S-R strategies. We used non-metric multidimensional scaling to examine the role of environmental factors such as soil properties, forest structure and management. Disturbance, in particular the frequency of harrowing, led to a decline in species richness and modified the indicator species and functional diversity by favoring Ruderal (R) species at the expense Stress-Tolerant (S) and Competitor (C) species, which are better suited to riparian forest conditions. Poplar plantations should not be used as surrogates for riparian forests, and minimizing harrowing in poplar plantations promotes vascular plant diversity. Furthermore, reintroduction of herbs, ferns and geophytes with a high conservation value and low seed dispersal capacity is advisable from the sixth year after establishment, once harrowing for weed control has been completed. Full article

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Open AccessArticle

White Spruce Growth and Wood Properties over Multiple Time Periods in Relation to Current Tree and Stand Attributes

by Francesco Cortini, Dan A. MacIsaac and Philip G. Comeau

Forests 2016, 7(3), 49; https://doi.org/10.3390/f7030049 - 24 Feb 2016

Cited by 4 | Viewed by 4163

Abstract

The relationships between white spruce radial increment and wood properties were investigated in relation to tree and stand attributes using data from mature white spruce stands in the boreal forest of western Canada that experienced a range of shelterwood treatments. The model with [...] Read more.

The relationships between white spruce radial increment and wood properties were investigated in relation to tree and stand attributes using data from mature white spruce stands in the boreal forest of western Canada that experienced a range of shelterwood treatments. The model with the highest predictive ability was radial increment (adj-R² = 67%) and included crown attributes, diameter at breast height (DBH), average height of competitors, and a climate index. Radial growth was positively related to live crown ratio, whereas wood density and modulus of elasticity were negatively correlated to the crown attribute. Tree slenderness had a significant negative effect on wood density and modulus of elasticity, as it reflects the mechanical stability requirement of the tree. The models consistently improved when using annual averages calculated over longer periods of time. However, when the annual averages were calculated using time periods of 5–10 and 10–20 years prior to sampling, the predictive ability of the models decreased, which indicated that the current tree and stand conditions were the best predictors of growth and wood properties up to five years prior to sampling. This study suggests that crown length equal to 2/3 of the tree height might represent an optimal balance between radial growth and wood quality. Full article

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Open AccessArticle

National Assessment of the Fragmentation Levels and Fragmentation-Class Transitions of the Forests in Mexico for 2002, 2008 and 2013

by Elizabeth Clay, Rafael Moreno-Sanchez, Juan Manuel Torres-Rojo and Francisco Moreno-Sanchez

Forests 2016, 7(3), 48; https://doi.org/10.3390/f7030048 - 24 Feb 2016

Cited by 15 | Viewed by 5499

Abstract

Landscape modification and habitat fragmentation are key drivers of global species and biodiversity loss, as well as a major threat to the conservation of forest ecosystems. Mexico is one of the five biologically richest countries in the world. This study first generated a [...] Read more.

Landscape modification and habitat fragmentation are key drivers of global species and biodiversity loss, as well as a major threat to the conservation of forest ecosystems. Mexico is one of the five biologically richest countries in the world. This study first generated a national level assessment of the fragmentation of temperate and tropical forests in Mexico for 2002, 2008, and 2013. Then, using these results, it explores how transitions to non-forest or to other fragmentation classes have evolved within the previous date fragmentation classes for the 2002–2008 and 2008–2013 periods. The Morphological Spatial Pattern Analysis (MSPA) method was used to assess the forest fragmentation. The results show that high fragmentation classes are more likely to transition to no-forest land covers in tropical than in temperate forests and that these conversions were larger during 2002–2008 than during the 2008–2013 period in both forest types. When analyzing the transitions between fragmentation classes, a higher percent of the forest area remained the same fragmentation class between 2008 and 2013 than from 2002 to 2008. Transitions between forest fragmentation classes were relatively small compared to transitions to no-forest land covers, and transitions to higher fragmentation classes were slightly larger in tropical than in temperate forests. Full article

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