Forests

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Open AccessEditorial

Acknowledgement to Reviewers of Forests in 2015

by Forests Editorial Office

Forests 2016, 7(1), 26; https://doi.org/10.3390/f7010026 - 22 Jan 2016

Viewed by 3673

The editors of Forests would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2015. [...] Full article

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Open AccessArticle

Community Structure, Biodiversity, and Ecosystem Services in Treeline Whitebark Pine Communities: Potential Impacts from a Non-Native Pathogen

by Diana F. Tomback, Lynn M. Resler, Robert E. Keane, Elizabeth R. Pansing, Andrew J. Andrade and Aaron C. Wagner

Forests 2016, 7(1), 21; https://doi.org/10.3390/f7010021 - 19 Jan 2016

Cited by 43 | Viewed by 7222

Abstract

Whitebark pine (Pinus albicaulis) has the largest and most northerly distribution of any white pine (Subgenus Strobus) in North America, encompassing 18° latitude and 21° longitude in western mountains. Within this broad range, however, whitebark pine occurs within a narrow [...] Read more.

Whitebark pine (Pinus albicaulis) has the largest and most northerly distribution of any white pine (Subgenus Strobus) in North America, encompassing 18° latitude and 21° longitude in western mountains. Within this broad range, however, whitebark pine occurs within a narrow elevational zone, including upper subalpine and treeline forests, and functions generally as an important keystone and foundation species. In the Rocky Mountains, whitebark pine facilitates the development of krummholz conifer communities in the alpine-treeline ecotone (ATE), and thus potentially provides capacity for critical ecosystem services such as snow retention and soil stabilization. The invasive, exotic pathogen Cronartium ribicola, which causes white pine blister rust, now occurs nearly rangewide in whitebark pine communities, to their northern limits. Here, we synthesize data from 10 studies to document geographic variation in structure, conifer species, and understory plants in whitebark pine treeline communities, and examine the potential role of these communities in snow retention and regulating downstream flows. Whitebark pine mortality is predicted to alter treeline community composition, structure, and function. Whitebark pine losses in the ATE may also alter response to climate warming. Efforts to restore whitebark pine have thus far been limited to subalpine communities, particularly through planting seedlings with potential blister rust resistance. We discuss whether restoration strategies might be appropriate for treeline communities. Full article

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

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Open AccessArticle

Synthesis and New Observations on Needle Pathogens of Larch in Northern Finland

by Risto Jalkanen

Forests 2016, 7(1), 25; https://doi.org/10.3390/f7010025 - 18 Jan 2016

Cited by 6 | Viewed by 5395

Abstract

Needle pathogens of larch (Larix spp.) in the Nordic countries are under-studied. Their incidence in Finland tends to be low and local, and this may be a function of enemy release, since species of larch were introduced to the region. Here, the [...] Read more.

Needle pathogens of larch (Larix spp.) in the Nordic countries are under-studied. Their incidence in Finland tends to be low and local, and this may be a function of enemy release, since species of larch were introduced to the region. Here, the ecology and incidence of larch needle pathogens and the abiotic factors that also affect larch in northern Finland are reviewed. Field observations and related laboratory analyses during the past 35 years have mainly been obtained near the Kivalo Research Area within the Arctic Circle, Finnish Lapland. The relatively recent introduction of Hypodermella laricis is a primary focus. This pathogen is not only new to Nordic countries, but can cause severe outbreaks, defoliation and crown-thinning in the canopies of all ages of most planted larch species worldwide. Symptoms of H. laricis clearly differ from those of Mycosphaerella laricina; the latter has affected Larix sibirica at high latitudes for decades. The effects of Meria laricis, Lophodermium laricinum, various rust fungi, and wind and frost are also discussed. Full article

(This article belongs to the Special Issue Joint IUFRO 7.02.02 “Foliage, shoot and stem diseases of forest trees” and 7.03.04 “Diseases and insects in forest nurseries” Working Parties Meeting)

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Open AccessArticle

Exploring Opportunities for Promoting Synergies between Climate Change Adaptation and Mitigation in Forest Carbon Initiatives

by Eugene L. Chia, Kalame Fobissie and Markku Kanninen

Forests 2016, 7(1), 24; https://doi.org/10.3390/f7010024 - 15 Jan 2016

Cited by 12 | Viewed by 6391

Abstract

There is growing interest in designing and implementing climate change mitigation and adaptation (M + A) in synergy in the forest and land use sectors. However, there is limited knowledge on how the planning and promotion of synergies between M + A can [...] Read more.

There is growing interest in designing and implementing climate change mitigation and adaptation (M + A) in synergy in the forest and land use sectors. However, there is limited knowledge on how the planning and promotion of synergies between M + A can be operationalized in the current efforts to mitigate climate change through forest carbon. This paper contributes to fill this knowledge gap by exploring ways of planning and promoting M + A synergy outcomes in forest carbon initiatives. It examines eight guidelines that are widely used in designing and implementing forest carbon initiatives. Four guiding principles with a number of criteria that are relevant for planning synergy outcomes in forest carbon activities are proposed. The guidelines for developing forest carbon initiatives need to demonstrate that (1) the health of forest ecosystems is maintained or enhanced; (2) the adaptive capacity of forest-dependent communities is ensured; (3) carbon and adaptation benefits are monitored and verified; and (4) adaptation outcomes are anticipated and planned in forest carbon initiatives. The forest carbon project development guidelines can encourage the integration of adaptation in forest carbon initiatives. However, their current efforts guiding projects and programs to deliver biodiversity and environmental benefits, ecosystem services, and socioeconomic benefits are not considered explicitly as efforts towards enhancing adaptation. An approach for incentivizing and motivating project developers, guideline setters, and offset buyers is imperative in order to enable existing guidelines to make clear contributions to adaptation goals. We highlight and discuss potential ways of incentivizing and motivating the explicit planning and promotion of adaptation outcomes in forest carbon initiatives. Full article

(This article belongs to the Collection Forests Carbon Fluxes and Sequestration)

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Open AccessArticle

A Quantitative Assessment of Forest Cover Change in the Moulouya River Watershed (Morocco) by the Integration of a Subpixel-Based and Object-Based Analysis of Landsat Data

by Fernando J. Aguilar, Abderrahim Nemmaoui, Manuel A. Aguilar, Mimoun Chourak, Yassine Zarhloule and Andrés M. García Lorca

Forests 2016, 7(1), 23; https://doi.org/10.3390/f7010023 - 15 Jan 2016

Cited by 16 | Viewed by 8132

Abstract

A quantitative assessment of forest cover change in the Moulouya River watershed (Morocco) was carried out by means of an innovative approach from atmospherically corrected reflectance Landsat images corresponding to 1984 (Landsat 5 Thematic Mapper) and 2013 (Landsat 8 Operational Land Imager). An [...] Read more.

A quantitative assessment of forest cover change in the Moulouya River watershed (Morocco) was carried out by means of an innovative approach from atmospherically corrected reflectance Landsat images corresponding to 1984 (Landsat 5 Thematic Mapper) and 2013 (Landsat 8 Operational Land Imager). An object-based image analysis (OBIA) was undertaken to classify segmented objects as forested or non-forested within the 2013 Landsat orthomosaic. A Random Forest classifier was applied to a set of training data based on a features vector composed of different types of object features such as vegetation indices, mean spectral values and pixel-based fractional cover derived from probabilistic spectral mixture analysis). The very high spatial resolution image data of Google Earth 2013 were employed to train/validate the Random Forest classifier, ranking the NDVI vegetation index and the corresponding pixel-based percentages of photosynthetic vegetation and bare soil as the most statistically significant object features to extract forested and non-forested areas. Regarding classification accuracy, an overall accuracy of 92.34% was achieved. The previously developed classification scheme was applied to the 1984 Landsat data to extract the forest cover change between 1984 and 2013, showing a slight net increase of 5.3% (ca. 8800 ha) in forested areas for the whole region. Full article

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Open AccessArticle

A Global Index for Mapping the Exposure of Water Resources to Wildfire

by François-Nicolas Robinne, Carol Miller, Marc-André Parisien, Monica B. Emelko, Kevin D. Bladon, Uldis Silins and Mike Flannigan

Forests 2016, 7(1), 22; https://doi.org/10.3390/f7010022 - 13 Jan 2016

Cited by 29 | Viewed by 10206

Abstract

Wildfires are keystone components of natural disturbance regimes that maintain ecosystem structure and functions, such as the hydrological cycle, in many parts of the world. Consequently, critical surface freshwater resources can be exposed to post-fire effects disrupting their quantity, quality and regularity. Although [...] Read more.

Wildfires are keystone components of natural disturbance regimes that maintain ecosystem structure and functions, such as the hydrological cycle, in many parts of the world. Consequently, critical surface freshwater resources can be exposed to post-fire effects disrupting their quantity, quality and regularity. Although well studied at the local scale, the potential extent of these effects has not been examined at the global scale. We take the first step toward a global assessment of the wildfire water risk (WWR) by presenting a spatially explicit index of exposure. Several variables related to fire activity and water availability were identified and normalized for use as exposure indicators. Additive aggregation of those indicators was then carried out according to their individual weight. The resulting index shows the greatest exposure risk in the tropical wet and dry forests. Intermediate exposure is indicated in mountain ranges and dry shrublands, whereas the lowest index scores are mostly associated with high latitudes. We believe that such an approach can provide important insights for water security by guiding global freshwater resource preservation. Full article

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

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Open AccessArticle

Quantifying the Impacts of Systemic Acquired Resistance to Pitch Canker on Monterey Pine Growth Rate and Hyperspectral Reflectance

by Gregory J. Reynolds, Thomas R. Gordon and Neil McRoberts

Forests 2016, 7(1), 20; https://doi.org/10.3390/f7010020 - 12 Jan 2016

Cited by 13 | Viewed by 5063

Abstract

Pitch canker, caused by Fusarium circinatum, is a disease affecting Monterey pine (Pinus radiata) and many other pine species throughout the world. The impact of pitch canker on Pinus radiata may be limited by systemic acquired resistance (SAR), a phenomenon that [...] Read more.

Pitch canker, caused by Fusarium circinatum, is a disease affecting Monterey pine (Pinus radiata) and many other pine species throughout the world. The impact of pitch canker on Pinus radiata may be limited by systemic acquired resistance (SAR), a phenomenon that elevates resistance to a pathogen after initial challenge by that pathogen or another microorganism. Allocation of resources to defense, as a consequence of SAR, is presumed to reduce resources available to support growth and reproduction, but specific fitness consequences associated with SAR in P. radiata have not been measured. To quantify impacts of SAR on growth rate, a 2 × 2 factorial experiment was established in which trees were either primed for SAR or unprimed, with half the trees in each of those two groups being inoculated with the pitch canker pathogen and the other half not inoculated. Priming for SAR was accomplished by inoculating one branch with F. circinatum and removing inoculated branches prior to subsequent challenge inoculations (= disease treatments). Disease treatments included three inoculations that were removed for measurement of lesion length, and three additional inoculations that remained on the tree as a representation of persistent disease. Control trees were mock inoculated with water. Main effects of priming and disease did not result in significant effects on growth rate. Based on hyperspectral canopy reflectance data, diseased trees were associated with higher difference vegetation index values and biomass. The absence of a negative impact on growth rate associated with SAR suggests that induction of resistance may have utility as a tool for management of pitch canker in plantations. Full article

(This article belongs to the Special Issue Joint IUFRO 7.02.02 “Foliage, shoot and stem diseases of forest trees” and 7.03.04 “Diseases and insects in forest nurseries” Working Parties Meeting)

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Open AccessArticle

Environmental Drivers of Patterns of Plant Diversity Along a Wide Environmental Gradient in Korean Temperate Forests

by Chang-Bae Lee and Jung-Hwa Chun

Forests 2016, 7(1), 19; https://doi.org/10.3390/f7010019 - 12 Jan 2016

Cited by 27 | Viewed by 5376

Abstract

Understanding patterns of biodiversity and their drivers along environmental gradients is one of the central topics in ecology. However, whether diversity patterns along environmental gradients differ among diversity components as well as life forms and what kind of variables control or interact to [...] Read more.

Understanding patterns of biodiversity and their drivers along environmental gradients is one of the central topics in ecology. However, whether diversity patterns along environmental gradients differ among diversity components as well as life forms and what kind of variables control or interact to shape the diversity patterns are poorly known. This study scrutinized the distribution patterns of three plant groups with four diversity indices and evaluated the effects of regional area, topography, topographic heterogeneity, climate, primary productivity, vegetation structure diversity and vegetation type diversity along an extensive elevational gradient on the Baekdudaegan Mountains in South Korea. Different elevational patterns, including hump-shaped, reversed hump-shaped, increasing, multimodal and no relationship, were observed among both the diversity indices and the plant groups. Regional area, habitat heterogeneity and climate were included to explain most of the elevational diversity patterns. In particular, habitat heterogeneity was the most important variable for explaining the patterns of diversity. The results suggest that patterns of elevational diversity may differ not only among plant groups but also among diversity indices and that such patterns are primarily caused by habitat heterogeneity in the Baekdudaegan Mountains because more heterogeneous and diverse habitats can support more coexisting species. Full article

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Open AccessArticle

A Comparison of Hierarchical and Non-Hierarchical Bayesian Approaches for Fitting Allometric Larch (Larix.spp.) Biomass Equations

by Dongsheng Chen, Xingzhao Huang, Xiaomei Sun, Wu Ma and Shougong Zhang

Forests 2016, 7(1), 18; https://doi.org/10.3390/f7010018 - 11 Jan 2016

Cited by 6 | Viewed by 5273

Abstract

Accurate biomass estimations are important for assessing and monitoring forest carbon storage. Bayesian theory has been widely applied to tree biomass models. Recently, a hierarchical Bayesian approach has received increasing attention for improving biomass models. In this study, tree biomass data were obtained [...] Read more.

Accurate biomass estimations are important for assessing and monitoring forest carbon storage. Bayesian theory has been widely applied to tree biomass models. Recently, a hierarchical Bayesian approach has received increasing attention for improving biomass models. In this study, tree biomass data were obtained by sampling 310 trees from 209 permanent sample plots from larch plantations in six regions across China. Non-hierarchical and hierarchical Bayesian approaches were used to model allometric biomass equations. We found that the total, root, stem wood, stem bark, branch and foliage biomass model relationships were statistically significant (p-values < 0.001) for both the non-hierarchical and hierarchical Bayesian approaches, but the hierarchical Bayesian approach increased the goodness-of-fit statistics over the non-hierarchical Bayesian approach. The R² values of the hierarchical approach were higher than those of the non-hierarchical approach by 0.008, 0.018, 0.020, 0.003, 0.088 and 0.116 for the total tree, root, stem wood, stem bark, branch and foliage models, respectively. The hierarchical Bayesian approach significantly improved the accuracy of the biomass model (except for the stem bark) and can reflect regional differences by using random parameters to improve the regional scale model accuracy. Full article

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Open AccessReview

Scientometrics of Forest Health and Tree Diseases: An Overview

by Marco Pautasso

Forests 2016, 7(1), 17; https://doi.org/10.3390/f7010017 - 08 Jan 2016

Cited by 7 | Viewed by 7186

Abstract

Maintaining forest health is a worldwide challenge due to emerging tree diseases, shifts in climate conditions and other global change stressors. Research on forest health is thus accumulating rapidly, but there has been little use of scientometric approaches in forest pathology and dendrology. [...] Read more.

Maintaining forest health is a worldwide challenge due to emerging tree diseases, shifts in climate conditions and other global change stressors. Research on forest health is thus accumulating rapidly, but there has been little use of scientometric approaches in forest pathology and dendrology. Scientometrics is the quantitative study of trends in the scientific literature. As with all tools, scientometrics needs to be used carefully (e.g., by checking findings in multiple databases) and its results must be interpreted with caution. In this overview, we provide some examples of studies of patterns in the scientific literature related to forest health and tree pathogens. Whilst research on ash dieback has increased rapidly over the last years, papers mentioning the Waldsterben have become rare in the literature. As with human health and diseases, but in contrast to plant health and diseases, there are consistently more publications mentioning “tree health” than “tree disease,” possibly a consequence of the often holistic nature of forest pathology. Scientometric tools can help balance research attention towards understudied emerging risks to forest trees, as well as identify temporal trends in public interest in forests and their health. Full article

(This article belongs to the Special Issue Joint IUFRO 7.02.02 “Foliage, shoot and stem diseases of forest trees” and 7.03.04 “Diseases and insects in forest nurseries” Working Parties Meeting)

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Open AccessArticle

Influences of Land Use Change on Baseflow in Mountainous Watersheds

by Xu-Dong Huang, Zhi-Hua Shi, Nu-Fang Fang and Xuan Li

Forests 2016, 7(1), 16; https://doi.org/10.3390/f7010016 - 06 Jan 2016

Cited by 33 | Viewed by 6074

Abstract

It is crucial for effective water resource management in a watershed that the relationship between land use changes and baseflow. This study quantifies the influence of land use changes on the baseflow dynamics using a hydrological model and partial least-squares (PLS) regression in [...] Read more.

It is crucial for effective water resource management in a watershed that the relationship between land use changes and baseflow. This study quantifies the influence of land use changes on the baseflow dynamics using a hydrological model and partial least-squares (PLS) regression in the Upper Du Watershed (8961 km²), China. Our study suggests that forest can be a major factor with a negative impact on the baseflow. Additionally, farmland and urban land have second-order negative effects on the baseflow dynamics. Baseflow increases when forest is replaced by farmland because the evapotranspiration (ET), associated with baseflow recession, is weaker and shorter in duration in the farmland than in the forest. The conversion of forest to urban land increases baseflow owing to the presence of non-contributing impervious surfaces in urban areas, which prevents the urban land from intercepting the baseflow discharge. These results indicate that the baseflow dynamics are closely associated with varying land use types within a watershed. Thus, this study is intended to provide a deeper understanding of the baseflow processes and useful quantitative information on land use factors in watersheds, enabling more informed decision-making in forest and watershed management. Full article

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

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Open AccessArticle

Labile and Non-Labile Fractions of Phosphorus and Its Transformations in Soil under Eucalyptus Plantations, Brazil

by Marlon Gomes Costa, Antonio Carlos Gama-Rodrigues, José Leonardo de Moraes Gonçalves, Emanuela Forestieri Gama-Rodrigues, Marcus Vinicius da Silva Sales and Seldon Aleixo

Forests 2016, 7(1), 15; https://doi.org/10.3390/f7010015 - 06 Jan 2016

Cited by 56 | Viewed by 8302

Abstract

Phosphorus (P) is the main limiting nutritional factor in the cultivation of Eucalyptus in Brazil. Despite this, little is known about the P fractions and dynamics in Eucalyptus soils in tropical regions. The aims of this study were (1) to evaluate the distribution [...] Read more.

Phosphorus (P) is the main limiting nutritional factor in the cultivation of Eucalyptus in Brazil. Despite this, little is known about the P fractions and dynamics in Eucalyptus soils in tropical regions. The aims of this study were (1) to evaluate the distribution of labile and non-labile fractions of P in soil in 10 sites of Eucalyptus in the state of São Paulo, Brazil and (2) to determine the interactions among the P fractions and to identify which fractions act as sinks or sources for the available P fraction. The P fractions were separated using the Hedley sequential extraction method, and the P transformation processes were evaluated via structural equation modeling. The labile P (resin-Pi + Pi and Po in NaHCO₃) varied between 6% and 16%, the moderately labile P (Pi + Po in NaOH) varied between 28% and 40%, the occluded P (Pi + Po in Sonicate + NaOH) varied between 6% and 19%, the P associated with Ca (HCl-Pi) varied between 0.4% and 3% and the residual-P varied between 35% and 47%. The hypothetical structural model of soil P cycle was composed of four P pools (latent variables): the organic pool, occluded pool, inorganic pool, and available pool. The structural model was adequate to identify functional pools of P in soil, and to identify transformation processes of P based on the source-sink relationships. The available P pool was highly dependent on inorganic and occluded pools and the organic pool acted predominantly as a sink of P on available and inorganic pools. The results reinforce the high level of recalcitrance of the organic pool and the fact that Eucalyptus plants must access pools of limited-availability P to meet their nutritional demands. Full article

(This article belongs to the Special Issue Eucalyptus and Pine Nutritional Diagnosis and Fertilizer Prescriptions)

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Open AccessArticle

Assessments of Population Structure, Diversity, and Phylogeography of the Swiss Needle Cast Fungus (Phaeocryptopus gaeumannii) in the U.S. Pacific Northwest

by Patrick Bennett and Jeffrey Stone

Forests 2016, 7(1), 14; https://doi.org/10.3390/f7010014 - 06 Jan 2016

Cited by 11 | Viewed by 5225

Abstract

Swiss needle cast (SNC) is a foliar disease of Douglas-fir (Pseudotsuga menziesii) caused by Phaeocryptopus gaeumannii (Rohde) Petrak. This fungus is endemic to western North America, where it has historically had little impact in native forests. However, increasing disease severity in [...] Read more.

Swiss needle cast (SNC) is a foliar disease of Douglas-fir (Pseudotsuga menziesii) caused by Phaeocryptopus gaeumannii (Rohde) Petrak. This fungus is endemic to western North America, where it has historically had little impact in native forests. However, increasing disease severity in western Oregon since the 1990s has prompted renewed interest in P. gaeumannii and SNC. For this study, we analyze multilocus microsatellite genotypes from 482 single-spore isolates from 68 trees across 14 sites in the western Coast Range of Oregon and southwestern Washington. This study assesses genotypic variation and genetic structure at several levels of population hierarchy. Despite the observation that most of the genetic variation occurred within subpopulations, our analyses detected significant differentiation at all hierarchical levels. Clustering among the 482 isolates based on genetic distance clearly supports the existence of two previously described cryptic lineages of P. gaeumannii in the western United States. The two lineages occur in varying proportions along latitudinal and longitudinal gradients in western Oregon and Washington, suggesting a relationship between climate and phylogeography. Sites near Tillamook, Oregon, where SNC is most severe, consist of sympatric subpopulations in which the two lineages comprise roughly equal proportions. Full article

(This article belongs to the Special Issue Joint IUFRO 7.02.02 “Foliage, shoot and stem diseases of forest trees” and 7.03.04 “Diseases and insects in forest nurseries” Working Parties Meeting)

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Open AccessArticle

Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China

by Yang Lu, Sailesh Ranjitkar, Jian-Chu Xu, Xiao-Kun Ou, Ying-Zai Zhou, Jian-Fang Ye, Xun-Feng Wu, Horst Weyerhaeuser and Jun He

Forests 2016, 7(1), 12; https://doi.org/10.3390/f7010012 - 02 Jan 2016

Cited by 16 | Viewed by 7568

Abstract

Subtropical evergreen broad-leaved forest (EBLF) is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of [...] Read more.

Subtropical evergreen broad-leaved forest (EBLF) is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ≥50% for 19 species. The median length of germination time (MLG) ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (≥15 cm in height) within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration. Full article

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Open AccessArticle

History and Productivity Determine the Spatial Distribution of Key Habitats for Biodiversity in Norwegian Forest Landscapes

by Magne Sætersdal, Ivar Gjerde, Einar Heegaard, Fride Høistad Schei and Jan Erik Ørnelund Nilsen

Forests 2016, 7(1), 11; https://doi.org/10.3390/f7010011 - 02 Jan 2016

Cited by 2 | Viewed by 5653

Abstract

Retention forestry, including the retention of woodland key habitats (WKH) at the forest stand scale, has become an essential management practice in boreal forests. Here, we investigate the spatial distribution of 9470 habitat patches, mapped according to the Complementary Habitat Inventory method (CHI [...] Read more.

Retention forestry, including the retention of woodland key habitats (WKH) at the forest stand scale, has become an essential management practice in boreal forests. Here, we investigate the spatial distribution of 9470 habitat patches, mapped according to the Complementary Habitat Inventory method (CHI habitats), as potential WKHs in 10 sample areas in Norway. We ask whether there are parts of the forest landscapes that have consistently low or high density of CHI habitats compared to the surveyed landscape as a whole, and therefore have a low or high degree of conflict with harvesting, respectively. We found that there was a general pattern of clumped distribution of CHI habitats at distances up to a few kilometres. Furthermore, results showed that most types of CHI habitats were approximately two to three times as common in the 25% steepest slopes, lowest altitudes and highest site indices. CHI habitats that are most common in old-growth forests were found at longer distances from roads, whereas habitats rich in deciduous trees were found at shorter distances from roads than expected. Both environmental factors and the history of human impact are needed to explain the spatial distribution of CHI habitats. The overrepresentation of WKHs in parts of the forest landscapes represents a good starting point to develop more efficient inventory methods. Full article

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Open AccessArticle

Foundation Species Loss and Biodiversity of the Herbaceous Layer in New England Forests

by Aaron M. Ellison, Audrey A. Barker Plotkin and Shah Khalid

Forests 2016, 7(1), 9; https://doi.org/10.3390/f7010009 - 25 Dec 2015

Cited by 15 | Viewed by 6103

Abstract

Eastern hemlock (Tsuga canadensis) is a foundation species in eastern North American forests. Because eastern hemlock is a foundation species, it often is assumed that the diversity of associated species is high. However, the herbaceous layer of eastern hemlock stands generally [...] Read more.

Eastern hemlock (Tsuga canadensis) is a foundation species in eastern North American forests. Because eastern hemlock is a foundation species, it often is assumed that the diversity of associated species is high. However, the herbaceous layer of eastern hemlock stands generally is sparse, species-poor, and lacks unique species or floristic assemblages. The rapidly spreading, nonnative hemlock woolly adelgid (Adelges tusgae) is causing widespread death of eastern hemlock. Loss of individual hemlock trees or whole stands rapidly leads to increases in species richness and cover of shrubs, herbs, graminoids, ferns, and fern-allies. Naively, one could conclude that the loss of eastern hemlock has a net positive effect on biodiversity. What is lost besides hemlock, however, is landscape-scale variability in the structure and composition of the herbaceous layer. In the Harvard Forest Hemlock Removal Experiment, removal of hemlock by either girdling (simulating adelgid infestation) or logging led to a proliferation of early-successional and disturbance-dependent understory species. In other declining hemlock stands, nonnative plant species expand and homogenize the flora. While local richness increases in former eastern hemlock stands, between-site and regional species diversity will be further diminished as this iconic foundation species of eastern North America succumbs to hemlock woolly adelgid. Full article

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

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Open AccessArticle

Adaptation of Forest Management Regimes in Southern Sweden to Increased Risks Associated with Climate Change

by Narayanan Subramanian, Johan Bergh, Ulf Johansson, Urban Nilsson and Ola Sallnäs

Forests 2016, 7(1), 8; https://doi.org/10.3390/f7010008 - 25 Dec 2015

Cited by 39 | Viewed by 12120

Abstract

Even though the growth rates of most tree species in Sweden is expected to increase in the near future as a result of climate change, increased risks of damage by storms and various pests and pathogens, notably root rot and bark beetles, may [...] Read more.

Even though the growth rates of most tree species in Sweden is expected to increase in the near future as a result of climate change, increased risks of damage by storms and various pests and pathogens, notably root rot and bark beetles, may also occur. Thus, forest management practices such as changes to thinning regimes, reductions in rotation lengths, and switching to other species (native or exotic) may represent adaptive management strategies to increase the resistance and resilience of Swedish forests to climate change. Clearly, thorough analyses examining the effects of anticipated climatic changes on damage levels, and the potentially relieving effects of possible management adaptations are needed before implementing such changes. In this study, damage caused by storms, root rot and bark beetles (single and in various combinations) under selected climate and management scenarios were simulated in Norway spruce (Pice abies L. Karst) stands. The results indicate that reductions in thinning intensity and rotation lengths could improve both volume production and profitability in southern Sweden. In addition, cultivation of rapidly growing species, such as hybrid larch (Larix × marschlinsii Coaz.) and hybrid aspen (Populus tremula L. × P. tremuloides Michx.), could be as profitable as Norway spruce cultivation, or even more profitable. However, slow-growing species, such as Silver birch (Betula pendula Roth), Downy birch (Betula pubescens Ehrh.) and European beech (Fagus sylvatica L.) indicated low economic output in terms of Land Expectation Value. Full article

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Open AccessArticle

Delphinella Shoot Blight on Abies lasiocarpa Provenances in Norway

by Venche Talgø, Jan-Ole Skage, Arne Steffenrem, Corina Junker, Håvard Eikemo, May Bente Brurberg and Odd Ragnar Johnskås

Forests 2016, 7(1), 7; https://doi.org/10.3390/f7010007 - 25 Dec 2015

Cited by 7 | Viewed by 8020

Abstract

Delphinella shoot blight (Delphinella abietis) attacks true firs (Abies spp.) in Europe and North America. Especially subalpine fir (A. lasiocarpa), one of the main Christmas tree species in Norway, is prone to the disease. The fungus kills current [...] Read more.

Delphinella shoot blight (Delphinella abietis) attacks true firs (Abies spp.) in Europe and North America. Especially subalpine fir (A. lasiocarpa), one of the main Christmas tree species in Norway, is prone to the disease. The fungus kills current year needles, and in severe cases entire shoots. Dead needles become covered with black fruiting bodies, both pycnidia and pseudothecia. Delphinella shoot blight has mainly been a problem in humid, coastal regions in the northwestern part of Southern Norway, but, probably due to higher precipitation in inland regions during recent years, heavy attacks were found in 2011 in a field trial with 76 provenances of subalpine fir in Southeastern Norway. However, the amount of precipitation seemed less important once the disease had established in the field. Significant differences in susceptibility between provenances were observed. In general, the more bluish the foliage was, the healthier the trees appeared. The analysis of provenance means indicated that, at least for the southern range, the disease ratings were correlated with foliage color. This study also includes isolation, identification, a pathogenicity test, a seed test and electron microscopy of the wax layer on the needles. The fungus was identified based on the morphology of spores and by sequencing the Internal Transcribed Spacer (ITS) regions of the ribosomal DNA. Koch’s postulates were fulfilled. The fungus was found present on newly harvested seeds and may therefore spread via international seed trade. When comparing the wax layers on green and blue needles, those of the latter were significantly thicker, a factor that may be involved in disease resistance. Full article

(This article belongs to the Special Issue Joint IUFRO 7.02.02 “Foliage, shoot and stem diseases of forest trees” and 7.03.04 “Diseases and insects in forest nurseries” Working Parties Meeting)

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1370 KiB

Open AccessArticle

Streamflow Regime Variations Following Ecological Management on the Loess Plateau, China

by Jianjun Zhang, Tingting Zhang, Yongnan Lei, Xiaoping Zhang and Rui Li

Forests 2016, 7(1), 6; https://doi.org/10.3390/f7010006 - 25 Dec 2015

Cited by 41 | Viewed by 4880

Abstract

The continuous ecological management of the Loess Plateau is known throughout the world for two strategies: the integrated soil conservation project that began in the 1970s, and the “Grain for Green” project that began in the 1990s. Six sub-catchments nested in the Beiluo [...] Read more.

The continuous ecological management of the Loess Plateau is known throughout the world for two strategies: the integrated soil conservation project that began in the 1970s, and the “Grain for Green” project that began in the 1990s. Six sub-catchments nested in the Beiluo River basin were selected to investigate streamflow regime variations during the two project periods. The annual streamflow trends and change points were detected using a bootstrap-based Mann-Kendall test and Pettitt test. Annual streamflow (from the 1950s to 2011) exhibited significantly negative trends in five out of six catchments, varying from −0.15 to −0.30 mm/a. During the integrated soil conservation period, the annual streamflow was reduced due to high flow decreases (5% of time exceeded), whereas in the low flows (95%) it increased in all sub-catchments. During the “Grain for Green” period, the annual streamflow decreased due to daily streamflow reductions at four stations. In addition to high flow and low flow decreases at the Wuqi and Liujiahe stations during the “Grain for Green” period, it is significant that the low flows continuously increased. Compared with trends from the forestry area, which includes the Zhangcunyi and Huangling stations, incremental annual streamflow reductions were observed in other sub-catchments, which can be linked to ecological management. This result implies that streamflow can be moderated by appropriate management options, even in semiarid areas. It was concluded that a stable streamflow regime can be achieved in vegetated areas, and streamflow moderation is dependent on ecological management practices. Full article

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

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4971 KiB

Open AccessArticle

Modeling Ecohydrological Processes and Spatial Patterns in the Upper Heihe Basin in China

by Bing Gao, Yue Qin, Yuhan Wang, Dawen Yang and Yuanrun Zheng

Forests 2016, 7(1), 10; https://doi.org/10.3390/f7010010 - 25 Dec 2015

Cited by 74 | Viewed by 8272

Abstract

The Heihe River is the second largest inland basin in China; runoff in the upper reach greatly affects the socio-economic development in the downstream area. The relationship between spatial vegetation patterns and catchment hydrological processes in the upper Heihe basin has remained unclear [...] Read more.

The Heihe River is the second largest inland basin in China; runoff in the upper reach greatly affects the socio-economic development in the downstream area. The relationship between spatial vegetation patterns and catchment hydrological processes in the upper Heihe basin has remained unclear to date. In this study, a distributed ecohydrological model is developed to simulate the hydrological processes with vegetation dynamics in the upper Heihe basin. The model is validated by hydrological observations at three locations and soil moisture observations at a watershed scale. Based on the simulated results, the basin water balance characteristics and their relationship with the vegetation patterns are analyzed. The mean annual precipitation and runoff increase with the elevation in a similar pattern. Spatial patterns of the actual evapotranspiration is mainly controlled by the precipitation and air temperature. At the same time, vegetation distribution enhances the spatial variability of the actual evapotranspiration. The highest actual evapotranspiration is around elevations of 3000–3600 m, where shrub and alpine meadow are the two dominant vegetation types. The results show the mutual interaction between vegetation dynamics and hydrological processes. Alpine sparse vegetation and alpine meadow dominate the high-altitude regions, which contribute most to the river runoff, and forests and shrub contribute relatively small amounts of water yield. Full article

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

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595 KiB

Open AccessArticle

Managed Mixtures of Aspen and White Spruce 21 to 25 Years after Establishment

by Richard Kabzems, Mike Bokalo, Philip G. Comeau and Daniel A. MacIsaac

Forests 2016, 7(1), 5; https://doi.org/10.3390/f7010005 - 24 Dec 2015

Cited by 20 | Viewed by 4168

Abstract

Intimate mixtures of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) are a key feature of western Canadian boreal forests. These mixtures have the potential to produce high yields of merchantable fibre and provide numerous ecological services. [...] Read more.

Intimate mixtures of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) are a key feature of western Canadian boreal forests. These mixtures have the potential to produce high yields of merchantable fibre and provide numerous ecological services. Achievement of this potential has been difficult, and often expensive, to realize as a regeneration goal in managed forests. We report 21 to 25 year results of managed mixtures on two study sites where the white spruce was planted, and the density of aspen natural regeneration manipulated within five years of the stand initiation disturbance. On both sites, white spruce mortality did not increase with increasing aspen density. While height and diameter growth of white spruce declined with increasing aspen density, the effect was not entirely consistent across the two sites. Abrasion from aspen branches was the most common source of damage to spruce crowns. Mixed stands had greater merchantable volume production than pure spruce stands based on model projections. Application of aspen harvest at year 60, while protecting the spruce component for a second harvest entry at year 90, was projected to optimize combined yield for the mixedwood stands. Full article

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1086 KiB

Open AccessCommunication

Consequences of Shifts in Abundance and Distribution of American Chestnut for Restoration of a Foundation Forest Tree

by Harmony J. Dalgleish, C. Dana Nelson, John A. Scrivani and Douglass F. Jacobs

Forests 2016, 7(1), 4; https://doi.org/10.3390/f7010004 - 24 Dec 2015

Cited by 45 | Viewed by 13329

Abstract

Restoration of foundation species, such as the American chestnut (Castanea dentata) that was devastated by an introduced fungus, can restore ecosystem function. Understanding both the current distribution as well as biogeographic patterns is important for restoration planning. We used United States [...] Read more.

Restoration of foundation species, such as the American chestnut (Castanea dentata) that was devastated by an introduced fungus, can restore ecosystem function. Understanding both the current distribution as well as biogeographic patterns is important for restoration planning. We used United States Department of Agriculture Forest Service Forest Inventory and Analysis data to quantify the current density and distribution of C. dentata. We then review the literature concerning biogeographic patterns in C. dentata. Currently, 431 ± 30.2 million stems remain. The vast majority (360 ± 22 million) are sprouts <2.5 cm dbh. Although this number is approximately 10% of the estimated pre-blight population, blight has caused a major shift in the size structure. The current-day population has a larger range, particularly west and north, likely due to human translocation. While climate change could facilitate northward expansion, limited seed reproduction makes this unlikely without assisted migration. Previous research demonstrates that the current, smaller population contains slightly higher genetic diversity than expected, although little information exists on biogeographic patterns in the genetics of adaptive traits. Our research provides a baseline characterization of the contemporary population of C. dentata, to enable monitoring stem densities and range limits to support restoration efforts. Full article

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1034 KiB

Open AccessArticle

The Interaction between FSC Certification and the Implementation of the EU Timber Regulation in Romania

by Ines Gavrilut, Aureliu-Florin Halalisan, Alexandru Giurca and Metodi Sotirov

Forests 2016, 7(1), 3; https://doi.org/10.3390/f7010003 - 22 Dec 2015

Cited by 20 | Viewed by 8923

Abstract

This explorative study aims to shed light on the ways in which Forest Stewardship Council (FSC) certification interacts with the implementation of the EU Timber Regulation (EUTR) in Romania. To this end, the EUTR implementation process is examined, and the relationship between this [...] Read more.

This explorative study aims to shed light on the ways in which Forest Stewardship Council (FSC) certification interacts with the implementation of the EU Timber Regulation (EUTR) in Romania. To this end, the EUTR implementation process is examined, and the relationship between this implementation and FSC certification is explored. There is a particular focus on the extent to which certification has helped companies to comply with EUTR requirements. The study uses the analytical framework of Transnational Business Governance Interactions (TBGI) and a mixed research approach. It is found that FSC certification has to a large extent helped companies to prepare for and align with the EUTR’s requirements, in particular concerning risk assessment and risk mitigation procedures needed for a due diligence system (DDS), and in the context of a “policy vacuum” period related to EUTR implementation. Moreover, recent changes in the FSC standard make it theoretically in line with EUTR requirements. However, difficulties remain in relation to the lack of information, costs and bureaucracy associated with both EUTR implementation and FSC certification. Notably, in the absence of a monitoring organization, the establishment of a viable DDS is still problematic as many companies remain unprepared for developing their own systems. Finally, the EUTR and its risk management requirements may have partly fueled the increase in uptake of chain of custody (CoC) certification in Romania. However, due to the risk of CoC certificates including illegally sourced timber, this recent uptake in certification does not necessarily indicate improved sustainable forest management (SFM) or full compliance with EUTR. Full article

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2908 KiB

Open AccessArticle

Responses of Clonal Eucalypt Plantations to N, P and K Fertilizer Application in Different Edaphoclimatic Conditions

by Eduardo Aparecido Sereguin Cabral de Melo, José Leonardo de Moraes Gonçalves, José Henrique Tertulino Rocha, Rodrigo Eiji Hakamada, José Henrique Bazani, Andrea Virginia Athayde Wenzel, José Carlos Arthur, Jr., Jarbas Silva Borges, Rogério Malheiros, Cristiane Camargo Zani de Lemos, Eric Victor de Oliveira Ferreira and Alexandre De Vicente Ferraz

Forests 2016, 7(1), 2; https://doi.org/10.3390/f7010002 - 22 Dec 2015

Cited by 48 | Viewed by 6614

Abstract

Eucalypt plantations in Brazil have the highest mean productivity when compared to other producing countries, and fertilizer application is one of the main factors responsible for these productivities. Our aim was to identify appropriate rates of N, P and K in eucalypt plantations [...] Read more.

Eucalypt plantations in Brazil have the highest mean productivity when compared to other producing countries, and fertilizer application is one of the main factors responsible for these productivities. Our aim was to identify appropriate rates of N, P and K in eucalypt plantations and their interactions with edaphoclimatic factors. Four trials with four rates and three nutrients (N, P and K) were set up. Each nutrient was studied separately, and the trees received sufficient rates of all of the other nutrients through fertilization, to avoid limitations not related to the desired nutrient. We assessed solid wood volume (SV), productivity gains (PG), leaf nutrient content and leaf area index (LAI) to determine the responses to fertilization. PG, regarding N, rates ranged from 104% to 127% at 60 months after planting. P fertilizer application led to gains in productivity in soils with levels of P-resin up to 5 mg·kg⁻¹, but decreased with stand age. K fertilizer application responses increased within age in three sites. In Paulistania, responses to K application were close to zero. N and K responses were climate related. Leaf nutrient content and LAI were not able to predict the highest yields obtained. Full article

(This article belongs to the Special Issue Eucalyptus and Pine Nutritional Diagnosis and Fertilizer Prescriptions)

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3693 KiB

Open AccessArticle

Detection of Airborne Inoculum of Hymenoscyphus fraxineus and H. albidus during Seasonal Fluctuations Associated with Absence of Apothecia

by Milon Dvorak, Gabriela Rotkova and Leticia Botella

Forests 2016, 7(1), 1; https://doi.org/10.3390/f7010001 - 22 Dec 2015

Cited by 39 | Viewed by 7723

Abstract

Hymenoscyphus fraxineus is an invasive fungal species causing the most serious disease of ashes (Fraxinus spp.) in Europe—ash dieback. The biology of this fungus is not totally elucidated, neither its relation to the saprophytic species Hymenoscyphus albidus, native in Europe. Our [...] Read more.

Hymenoscyphus fraxineus is an invasive fungal species causing the most serious disease of ashes (Fraxinus spp.) in Europe—ash dieback. The biology of this fungus is not totally elucidated, neither its relation to the saprophytic species Hymenoscyphus albidus, native in Europe. Our study is focused on the description of seasonal spore dispersal of both fungi and its relation to meteorological conditions, which is needed for more precise and effective control of the disease. For this experiment one long time infected mixed forest in the SE Czech Republic was chosen. A seven-day automatic volumetric spore trap and a weather station were installed to continuously sample the aerospora from April to October 2014. In seven periods a rotating arm spore trap was also used to obtain 48-h air samples to compare the efficiency of these two types of air samplers. Air samples were evaluated solely by qPCR with a very low detection limit. Results show co-occurrence of inoculum of both fungi throughout the entire sampling period with peak levels in August. The origin of the inoculum sampled in the periods without apothecia is discussed. Air-inoculum occurrence of both fungi is significantly correlated with each other, suggesting their coexistence in this forest. Full article

(This article belongs to the Special Issue Joint IUFRO 7.02.02 “Foliage, shoot and stem diseases of forest trees” and 7.03.04 “Diseases and insects in forest nurseries” Working Parties Meeting)

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Forests, Volume 7, Issue 1 (January 2016) – 25 articles

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