Forest Community Structure Research Articles

2017–2020年广东南岭典型植被类型木本植物物种组成数据集

Plant species composition is a vital indicator for studying the structure and functioning of forest ecosystems. It constitutes an important component of the China Ecosystem Research Network (CERN) and the long-term monitoring of terrestrial ecosystem biological elements. It can be utilized to assess and monitor biodiversity levels, environmental changes, and ecosystem responses. It holds utmost significance for natural resource management and land-use planning, providing crucial foundations for scientific research, policy-making, and ecological conservation. Nanling, as a significant ecological barrier in China, harbors the largest area of forests at the same latitude. It encompasses various vegetation types, including subtropical evergreen broad-leaved forests, subtropical mixed coniferous and broad-leaved forests, and subtropical dwarf evergreen broad-leaved forests. Following the monitoring specifications for terrestrial ecosystem biological elements, this paper presents the original data of all woody plant individuals with a diameter at breast height (DBH) ≥ 1 cm, including their species names, DBH, height, and other relevant information. These data were obtained through two consecutive census surveys conducted by the Guangdong Nanling Forest Ecosystem National Field Scientific Observation Research Station from 2017 to 2020. After meticulous data organization, quality control, and evaluation, the dataset provides detailed information on typical forest communities in Nanling, including plot numbers, vegetation types, species names, Latin names, abundance, relative abundance, relative dominance, relative frequency, importance value, and year of survey. This dataset serves as local data for in-depth investigation into biodiversity, community structure, and functions of forest communities in Nanling. Moreover, it aims to provide fundamental support for forest management, environmental protection, natural resource management, and sustainable development in the region.

Effect of fire and post-fire management on soil microbial communities in a lower subtropical forest ecosystem after a mountain fire

Wildfires and post-fire management exert profound effects on soil properties and microbial communities in forest ecosystems. Understanding microbial community recovery from fire and what the best post-fire management should be is very important but needs to be sufficiently studied. In light of these gaps in our understanding, this study aimed to assess the short-term effects of wildfire and post-fire management on both bacteria and fungi community composition, diversity, structure, and co-occurrence networks, and to identify the principal determinants of soil processes influencing the restoration of these communities. Specifically, we investigated soil bacterial and fungal community composition, diversity, structure, and co-occurrence networks in lower subtropical forests during a short-term (<3 years) post-fire recovery period at four main sites in Guangdong Province, southern China. Our results revealed significant effects of wildfires on fungal community composition, diversity, and co-occurrence patterns. Network analysis indicated reduced bacterial network complexity and connectivity post-fire, while the same features were enhanced in fungal networks. However, post-fire management effects on microbial communities were negligible. Bacterial diversity correlated positively with soil microbial biomass nitrogen, soil organic carbon, and soil total nitrogen. Conversely, based on the best random forest model, fungal community dynamics were negatively linked to nitrate-nitrogen and soil water content. Spearman's correlation analysis suggested positive associations between bacterial networks and soil factors, whereas fungal networks exhibited predominantly negative associations. This study elucidates the pivotal role of post-fire management in shaping ecological outcomes. Additionally, it accentuates the discernible distinctions between bacterial and fungal responses to fire throughout a short-term recovery period. These findings contribute novel insights that bear significance in evaluating the efficacy of environmental management strategies.

The tree layer structure of forest communities of the Kola Peninsula central part formed when aerotechnogenic emissions reduced

This research provides an overview of the main component of forest ecosystems in northern Europe, the tree layer formed by the Scotch pine (Pinus sylvestris L .) species. The studied communities are located in the immediate vicinity of the largest plant in Europe, OAO Severonickel (Monchegorsk, Murmansk region). The main pollutants are polymetallic dust containing elements such as Cu, Ni and Co (which are by-products of processing and smelting non-ferrous ores) and sulfur dioxide - SO2 (which is formed during the primary processing of ores, the so-called “roasting”). The first permanent trial plots (PPPs) in this region were established in the early 1970s. Since the second half of the 1990s, the plant has significantly reduced the amount of aerotechnogenic emissions, as evidenced by the data noted by some researchers at that time. The cumulative nature of the accumulation (and release) of polymetallic dust led to the fact that, starting from the time the ore processing plant reduced its capacity, the concentration of metals contained in the soil and plant organs decreased to a certain level. We present the materials obtained in the course of field research in 2015-2018.

Global warming leads to growth increase in Pinus sylvestris in the Kazakh steppe

Forest community structure and function in climate-sensitive regions exhibit uncertain changes under the influence of global warming. Especially in northern Central Asia, the response of pine growth to climate change remains unclear. Here, we identified changes in growth trends and climate response in a total of 646 trees for the abundant species Scots pine (Pinus sylvestris) at 30 sites in the Kazakh steppe. We used basal area increment, regional curve standardization and negative exponential curve detrended chronologies to comprehensively analyze trends in pine growth, and linear mixed effects and random forest models were calculated to explore growth-climate relationships. An increase in the overall growth of Scots pine under the influence of global warming, expressed in this region by increasing temperatures and precipitation, was observed during the period 1950–2018. Spatial differences in climate response between the sub-regions were identified showing that pine growth is more influenced by summer precipitation in the eastern compared to the western and central Kazakh steppe. Warm spring temperatures and more precipitation are important common climatic factors affecting pine growth in northern Central Asia. Moreover, increased drought intensity and longer drought duration negatively impact pine growth in this region. The Pacific Decadal Oscillation and North Atlantic Oscillation were identified to be the main atmospheric circulation patterns that influence the spatial differentiation in pine growth in this steppe. Albeit pine growth in northern Central Asia shows an increasing trend currently but also in future climate scenarios, the risks and challenges posed by drought should not be underestimated.

Layer structure and species composition of primeval habitat forest communities that include the tallest tree in karst areas of China

Layer structure and species composition of primeval habitat forest communities that include the tallest tree in karst areas of China

Local Topography Has Significant Impact on Dendroclimatic Response of Picea jezoensis and Determines Variation of Factors Limiting Its Radial Growth in the Southern Sikhote-Alin

Climate change significantly influences forest communities, even leading to their complete transformation. In the case of boreal and temperate forests, it is particularly important to understand how dominant tree species respond to climate changes, as they largely determine the structure of forest communities. In this study, we focus on the Jezo spruce (Picea jezoensis (Siebold &amp; Zucc.) Carriere), which is widespread in Northeast Asia. We investigated the climate parameters affecting the radial growth of Jezo spruce and how their influence changes along environmental gradients. For the research, 500 tree cores were collected from 10 sites located at elevations ranging from 460 to 1060 m. We found a negative response of Jezo spruce radial growth to precipitation in July–August and SPEI in July of the current year, maximum temperatures in July–August and November of the previous year. On the other hand, we observed a positive response to the maximum temperatures in January of the current year. Furthermore, we established that the influence of these climatic parameters depends on local topography, with 74.3% of the variance in response values being explained by elevation, slope, and the Topographic Position Index. The results obtained demonstrate that the reaction of Jezo spruce radial growth to climate change will be complex, and the balance between negative and positive effects will depend significantly on local topography.

Diversity and Structure of Soil Microbial Communities in Chinese Fir Plantations and Cunninghamia lanceolata–Phoebe bournei Mixed Forests at Different Successional Stages

Cunninghamia lanceolata is an important species in plantations and is widely planted in sub-tropical regions of China because of its fast-growing and productive characteristics. However, the monoculture planting is carried out in the pursuit of economic value. This planting mode has led to problems such as the exhaustion of soil fertility, decrease in vegetation diversity, and decrease in woodland productivity. In order to restore soil fertility and increase timber production, the introduction of broad-leaved tree species to plantations is an effective transformation model. Understanding how forest age changes and stand structure differences drive the composition and diversity of soil microbial communities is helpful in understanding the trend of soil–microbial changes in plantations and evaluating the effects of the introduction of broad-leaved tree species in soil–plant–microbial ecosystems in plantations. Therefore, the purpose of our study is to investigate the effects of forest age and pure forest conversion on C. lanceolata–P. bournei-mixed forest soil microbial community structure and diversity by detecting soil nutrients, enzyme activities, and soil microbial 16S and ITS rRNA gene sequencing. According to the findings, the diversity and abundance of bacterial communities in C. lanceolata plantations of different ages increased first and then decreased with the increase in forest age, and the max value was in the near-mature forest stage. The fungal abundance decreased gradually with stand age, with the lowest fungal diversity at the near-mature stand stage. During the whole growth process, the bacterial community was more limited by soil pH, nitrogen, and phosphorus. After introducing P. bournei into a Chinese fir plantation, the abundance and diversity of the bacterial community did not improve, and the abundance of the fungal community did not increase. However, soil nutrients, pH, and fungal community diversity were significantly improved. The results of these studies indicate that the introduction of broad-leaved tree species not only increased soil nutrient content, but also had a significant effect on the increase in the diversity of soil fungal communities, making the microbial communities of mixed forests more diverse.

Signatures of prescribed fire in the microbial communities of Cornus florida are largely undetectable five months post-fire.

Prescribed burn is a management tool that influences the physical structure and composition of forest plant communities and their associated microorganisms. Plant-associated microorganisms aid in host plant disease tolerance and increase nutrient availability. The effects of prescribed burn on microorganisms associated with native ecologically and economically important tree species, such as Cornus florida L. (flowering dogwood), are not well understood, particularly in aboveground plant tissues (e.g., leaf, stem, and bark tissues). The objective of this study was to use 16S rRNA gene and ITS2 region sequencing to evaluate changes in bacterial and fungal communities of five different flowering dogwood-associated niches (soil, roots, bark, stem, and leaves) five months following a prescribed burn treatment. The alpha- and beta-diversity of root bacterial/archaeal communities differed significantly between prescribed burn and unburned control-treated trees. In these bacterial/archaeal root communities, we also detected a significantly higher relative abundance of sequences identified as Acidothermaceae, a family of thermophilic bacteria. No significant differences were detected between prescribed burn-treated and unburned control trees in bulk soils or bark, stem, or leaf tissues. The findings of our study suggest that prescribed burn does not significantly alter the aboveground plant-associated microbial communities of flowering dogwood trees five months following the prescribed burn application. Further studies are required to better understand the short- and long-term effects of prescribed burns on the microbial communities of forest trees.

Bird diversity in the forests and coconut farms of Sulawesi, Indonesia

AbstractCoconut farming contributes to the livelihoods of millions of people in tropical countries but is less frequently considered as a threat to biodiversity compared to other palm commodities such as oil palm. The expansion of coconut farming alongside other smallholder agriculture in Sulawesi, Indonesia, is of potential concern as the region is a centre of species endemism. We studied bird diversity and community structure in forests, coconut palm plantations and mixed farmland in Gorontalo Province, northern Sulawesi. Forest and non-forest sites supported similar numbers of species overall, but compared to agricultural areas, forest sites had communities that were more diverse and more even (i.e. different species were present at similar abundances). We found far fewer endemic species in agricultural areas compared to forests, and the communities in palm plantations and mixed farmland sites were dominated by generalist birds, with few indicator taxa. Nevertheless, there was a higher number of endemic species in coconut palm plantations than in mixed farmland sites. These findings mirror patterns of biotic homogenization documented elsewhere in the Wallacea centre of endemism, and imply that coconut palm plantations have comparable biodiversity value to other farmland systems. Increased protection of lowland forests and improved management of coconut farms could be important for supporting the conservation of the endemic birds of Sulawesi in the long term, but this warrants further study.

Community structure and species diversity dynamics of a subtropical evergreen broad-leaved forest in China: 2005 to 2020

Here, we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China. We found that community structure in this forest changed over a 15-year period. Specifically, renewal and death of common species was large, with the renewal of individuals mainly concentrated within a few populations, especially those of Aidia canthioides and Cryptocarya concinna. The numbers of individual deaths for common species were concentrated in the small and mid-diameter level. The spatial distribution of community species diversity fluctuated in each monitoring period, showing a more dispersed diversity after the 15-year study period, and the coefficient of variation on quadrats increased. In 2010, the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years. Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests. Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long- and short-term causes of dynamic fluctuations of community structure and species diversity, and reveal the factors that drive changes in community structure.

Upland forest community composition and structure by ecoregion in 73 Florida state parks – Insights for ongoing management

Plot based forest/vegetation data is used to establish current conditions and inform natural resources management decisions. The Florida Department of Environmental Protection – Division of Recreation and Parks (DRP) manages 175 state parks. As part of its mission, DRP strives to restore landscapes and natural communities by reintroducing dynamic natural processes such as fire. DRP also uses other methods of active management to achieve desired future conditions (DFCs) in multiple communities including those characterized by longleaf pine (Pinus palustris Mill.) and native groundcover (GC) species. To meet the challenge of managing natural resources across the State, DRP initiated an objective and repeatable forest/vegetation inventory system. The primary objective of this paper was to analyze and summarize the resultant data and compare current community type (ComType) vegetation conditions. Current conditions were quantified using nested plots distributed within sample areas across 73 state parks and 15 ecoregions via the line-plot method. Over 37,000 plots were inventoried; 36% were in pine flatwoods. Ten actively managed and dominant ComTypes were central to this paper and when aggregated by ecoregion, 76 ComType by ecoregion (CTER) groups were examined. Descriptive statistics for various measurements, e.g., diameter at breast height, height, and density, were calculated for overstory, midstory and understory (vegetation layer) separately per CTER. Mean importance value index (IVI) was calculated by species or species-group per vegetation layer and CTER. Community classification was conducted via hierarchical clustering of CTERs per vegetation layer using mean IVI scores. Across CTERs, pine overstory and midstory abundance/stocking levels were generally low, non-pine overstory and midstory stocking levels were high, pine regeneration was sparse, and GC was dominated by leaf litter, pine straw, and non-pine woody seedlings. Results strongly suggest that some ComTypes were similar within certain ecoregions. Various pine species are considered dominant or one of the prominent overstory species for eight of the ten ComTypes. The ability to manage upland pine ComTypes using natural regeneration systems will become increasingly challenging in the near- to medium-term given relatively low overstory pine stocking for most CTERs, and the virtual lack of young pines within midstory and understory layers. Further investigations could help identify potential causal agents concerning low young pine stocking levels, e.g., timing and frequency of prescribed fires, frequency of logging, and/or increased competition from high densities of midstory non-pines and appropriate natural regeneration systems, e.g., seed tree, shelterwood, or group selection, or underplanting longleaf pine, that would accelerate understory pine recruitment.

Effects of bacteria on early-stage litter decomposition in Wudalianchi volcanic forest.

To understand the role of microorganisms in litter decomposition and nutrient cycling in volcanic forest ecosystem, we conducted in-situ litterbag decomposition experiment and used Illumina MiSeq high-throughput sequencing to analyze the response of bacterial community structure and diversity during the decomposition of litters from Larix gmelinii, Betula platyphylla and Populus davidiana, the dominant tree species in volcanic lava plateau of Wudalianchi. The results showed that mass remaining percentage of litters of three species after 18-month decomposition was 63.9%-68.1%. Litter of B. platyphylla decomposed the fastest, with significant difference in N, C:N, and N:P before and after decomposition. The richness of bacterial species and diversity index differed significantly among the three litters. Proteobacteria, Actinomycetes, and Bacteroidetes were the dominant bacterial groups at the phylum level, while Rhizobium, Sphingomonas, and Pseudomonas were the dominant groups at the genus level, with significant difference among the three litters. After 18 months, the dominant bacterial groups in litter tended to be consistent with those in volcanic lava platform soil. In the volcanic forest ecosystem, bacterial diversity and community structure were mainly affected by P, C:N, and N:P in the litter.

Forest Ecosystem Service Trade-Offs/Synergies and System Function Optimization in Karst Desertification Control.

Karst desertification control forests are essential for ecosystem multi functionality, but the trade-offs/synergies are unclear for forest ecosystem services. In order to clarify the trade-offs/synergies, this study was conducted on eight forest communities in a karst desertification control area and was based on vegetation surveys and structural and functional monitoring. It analyzes water holding capacity, species diversity, soil conservation, and carbon storage characteristics and their trade-off/synergies. The results indicate the following: (1) The Cladrastis platycarpa + Cotinus coggygria community (H1) had the highest water holding capacity and species diversity with values of 252.21 t·hm-2 and 2.56, respectively. Soil conservation was highest in the Zanthoxylum bungeanum + Glycine max community (H6), with an index value of 1.56. Carbon storage was the greatest in the Tectona grandis community (H8), at 103.93 t·hm-2. The results of these studies have shown that there are significant differences in different types of forest community ecosystem services. (2) Water holding capacity, species diversity, soil conservation, and carbon storage, all have synergistic relationships, suggesting a trend towards synergistic enhancement between the services. (3) The species diversity of the forest ecosystems was shown to be in a trade-off with carbon storage and soil conservation, which suggests that the services are in competition with each other. To further improve the service capacity of forest ecosystems, the trade-offs between the regulation of forest community structure and function and the improvement of services should be optimized.

Composition and community structure of Olea ferruginea Royle forests in Jammu and Kashmir, India

ABSTRACT Olea ferruginea Royle is a wild Olive species commonly known as Indian or African Olive. In India, it is distributed in the Northwestern Himalaya, from Jammu and Kashmir to Uttarakhand, at an altitude of up to 2400 m amsl. The present study aims to determine the composition and community structure of Olea L. forests in Jammu and Kashmir, India. During the present study, 21 sites were surveyed from September 2019‒August 2021 and a total of 34 plant species belonging to 32 genera and 22 families were recorded. Fabaceae was the dominant family with five species followed by Moraceae (four species) and Fagaceae, Rosaceae, Malvaceae, Meliaceae, and Salicaceae (two species each). A total of 1333 individuals of trees were recorded including 362 individuals of Olea ferruginea. From the dendrogram resulting from Ward’s cluster analysis of 21 sites based on presence/absence data, five communities were identified on the basis of the Importance Value Index (IVI). The species richness and diversity indices showed great differences from community to community. The present study provides baseline information about the community structure and biological associations of Olea ferruginea.

Identification of Tree Species in Forest Communities at Different Altitudes Based on Multi-Source Aerial Remote Sensing Data

The accurate identification of forest tree species is important for forest resource management and investigation. Using single remote sensing data for tree species identification cannot quantify both vertical and horizontal structural characteristics of tree species, so the classification accuracy is limited. Therefore, this study explores the application value of combining airborne high-resolution multispectral imagery and LiDAR data to classify tree species in study areas of different altitudes. Three study areas with different altitudes in Muyu Town, Shennongjia Forest Area were selected. Based on the object-oriented method for image segmentation, multi-source remote sensing feature extraction was performed. The recursive feature elimination algorithm was used to filter out the feature variables that were optimal for classifying tree species in each altitude study area. Four machine learning algorithms, SVM, KNN, RF, and XGBoost, were combined to classify tree species at each altitude and evaluate the accuracy. The results show that the diversity of tree layers decreased with the altitude in the different study areas. The texture features and height features extracted from LiDAR data responded better to the forest community structure in the different study areas. Coniferous species showed better classification than broad-leaved species within the same study areas. The XGBoost classification algorithm showed the highest accuracy of 87.63% (kappa coefficient of 0.85), 88.24% (kappa coefficient of 0.86), and 84.03% (kappa coefficient of 0.81) for the three altitude study areas, respectively. The combination of multi-source remote sensing numbers with the feature filtering algorithm and the XGBoost algorithm enabled accurate forest tree species classification.

Community Structure and Growth Rate of Korean Quercus mongolica Forests by Vegetation Climate Zone

Q. mongolica forests are representative forest types in Korea, belonging to the intermediate succession stage with the highest species diversity. Identifying the community structure and growth rate of Q. mongolica forests by the vegetation climate zone can help in planning efficient forest restoration strategies for each vegetation climate zone. The proportions of major communities based on the vegetation climate zones newly adjusted by the Korea National Arboretum in 2020 were determined. Major dominant species were identified in Quercus mongolica forests in which Q. mongolica dominates by more than 50% by analyzing the importance based on the basal area of the trees using data from the 7th National Forest Inventory Survey. The basal area growth rate was analyzed for permanent sample plots from the 5th to 7th National Forest Inventory Surveys. The analysis revealed statistically significant differences in the basal area growth rate by vegetation climate zone over a 10-year period. However, it should be noted that Q. mongolica forests with younger age classes were more abundant in the warm southern temperate zone; thus, it is likely that age class has a greater effect on the rate of basal area increase than the vegetation climate zone.

Fine root biomass and morphology in a temperate forest are influenced more by canopy water addition than by canopy nitrogen addition

IntroductionIncreasing atmospheric N deposition and changes in precipitation patterns could profoundly impact forest community structure and ecosystem functions. However, most N and water (W) addition experiments have focused on direct N application to leaf litter or soil, neglecting canopy processes such as leaf evaporation and absorption.MethodsIn this study, we aimed to assess the effects of atmospheric N deposition and increased precipitation on the fine root biomass and morphology of plants in a temperate deciduous forest. To achieve this, we applied N and W above the forest canopy and quantified the seasonal dynamics (January, July, and October) of fine root biomass and morphology.ResultsOur results revealed that only canopy W addition significantly increased the biomass of fine roots in January compared to that in other seasons (p &amp;lt; 0.05). We observed no significant interaction effect of N and W on fine root biomass. However, we found that the different growth seasons had a significant impact on the fine root biomass (p &amp;lt; 0.001). The combined application of N and W significantly affected the root tip density (p = 0.002). Although canopy N addition was significantly positively correlated with available soil N (p &amp;lt; 0.05), we detected no significant association with fine root biomass or morphology.DiscussionThe findings of this study indicated that fine root biomass and morphology, are affected to a greater extent by the provision of W than by N application. These findings provide a new perspective and a more precise understanding of the effects of the actual N deposition and precipitation on the dynamics of plant fine roots in forest ecosystems.

Seasonal variation in the soil fungal community structure of Larix gmelinii forests in Northeast China.

Soil fungi play an indispensable role in forest ecosystems by participating in energy flow, material circulation, and assisting plant growth and development. Larix gmelinii is the dominant tree species in the greater Khingan Mountains, which is the only cold temperate coniferous forest in China. Understanding the variations in underground fungi will help us master the situation of L. gmelinii above ground. We collected soil samples from three seasons and analyzed the differences in soil fungal community structure using high-throughput sequencing technology to study the seasonal changes in soil fungal community structure in L. gmelinii forests. We found that the Shannon and Chao1 diversity in autumn was significantly lower than in spring and summer. The community composition and functional guild varied significantly between seasons. Furthermore, we showed that ectomycorrhizal fungi dominated the functional guilds. The relative abundance of ectomycorrhizal fungi increased dramatically from summer to autumn and was significantly negatively correlated with temperature and precipitation. Temperature and precipitation positively affect the alpha diversity of fungi significantly. In addition, pH was negatively correlated with the Chao1 diversity. Temperature and precipitation significantly affected several dominant genera and functional guilds. Among the soil physicochemical properties, several dominant genera were affected by pH, and the remaining individual genera and functional guilds were significantly correlated with total nitrogen, available phosphorus, soil organic carbon, or cation exchange capacity. For the composition of total fungal community, temperature and precipitation, as well as soil physicochemical properties except AP, significantly drove the variation in community composition.

Biochar mitigates allelopathic effects in temperate trees.

Many invasive and some native tree species in North America exhibit strong allelopathic effects that may contribute to their local dominance. Pyrogenic carbon (PyC; including soot, charcoal, and black carbon) is produced by the incomplete combustion of organic matter and is widespread in forest soils. Many forms of PyC have sorptive properties that can reduce the bioavailability of allelochemicals. We investigated the potential for PyC produced by controlled pyrolysis of biomass ("biochar" [BC]) to reduce the allelopathic effects of black walnut (Juglans nigra) and Norway maple (Acer platanoides), a common native tree species and a widespread invasive species in North America, respectively. Seedling growth of two native tree species (Acer saccharinum [silver maple] and Betula papyrifera [paper birch]) in response to leaf-litter-incubated soils was examined; litter incubation treatments included leaves of black walnut, Norway maple, and a nonallelopathic species (Tilia americana [American basswood]) in a factorial design with varying dosages; responses to the known primary allelochemical of black walnut (juglone) were also examined. Juglone and leaf litter of both allelopathic species strongly suppressed seedling growth. BC treatments substantially mitigated these effects, consistent with the sorption of allelochemicals; in contrast no positive effects of BC were observed in leaf litter treatments involving controls or additions of nonallelopathic leaf litter. Treatments of leaf litter and juglone with BC increased the total biomass of silver maple by ~35% and in some cases more than doubled the biomass of paper birch. We conclude that BCs have the capacity to largely counteract allelopathic effects in temperate forest systems, suggesting the effects of natural PyC in determining forest community structure, and also the applied use of BC as a soil amendment to mitigate allelopathic effects of invasive tree species.

Non-native Douglas fir promotes epigeal spider density, but has a mixed effect on functional diversity

With climate change altering ecosystems worldwide, forest management in Europe is increasingly relying on more adaptable non-native tree species, such as Douglas fir (Pseudotsuga menziesii). However, the ecological consequences of the increased utilization of Douglas fir on arthropod diversity and ecosystem functioning are not fully known. Here we assessed how non-native Douglas fir as well as large- and small-scale differences in the environmental context, affect epigeal spider abundance, biomass, taxonomic and functional diversity, and community structure in Central European forests. Our study sites were divided into two regions with large differences in environmental conditions, with seven replicates of five stand types, including monocultures of native European beech (Fagus sylvatica), non-native Douglas fir and native Norway spruce (Picea abies), as well as two-species mixtures of European beech and each of the conifers. Contrary to our expectations, Douglas fir promoted small-scale spider diversity, and abundance and biomass (activity density). On the other hand, it decreased spider functional divergence and altered spider community structure. Microhabitat characteristics had opposing effects on spider diversity and activity density, with more open stands harboring a more diverse but less abundant spider community. Overall, our findings suggest that increasing Douglas fir utilization at the expense of Norway spruce does not necessarily decrease the diversity of epigeal arthropods and may even promote local spider diversity and activity density. However, care needs to be taken in terms of biodiversity conservation because typical forest spider species and their functional divergence were more strongly associated with native beech than with coniferous stands.