Aims: Plant community structure and diversity patterns research is valuable for revealing the mechanism of biodiversity maintenance. The Qinling Mountains are in the transition zone at the north-south climate dividing line where the flora and fauna meet. This region is an important platform for studying the plant community structure and diversity distribution pattern in the transition zone.

Methods: According to standards of Center for Tropical Forest Science (CTFS), the Smithson Institute for Tropical Research, we establish ten 1 ha (100 m × 100 m) long-term positional monitoring plots from 800 m to 2,600 m in the middle part of the southern slope of the Qinling Mountains. We conduct community surveys using our plots with the Qinling Huangguan forest plot as the core. Initially, we analyze the elevation gradient pattern of the species composition, systematic characters, diameter class structure, spatial distribution of dominant species, and species diversity of woody plants with diameter at breast height (DBH) ≥ 1 cm.

Results: (1) We investigate a total of 208 seed plant species belonging to 50 families and 109 genera. The genera in the temperate zone account for 69.7% of the total number of genera, and the temperate zone is obvious. With increasing elevation, rare and occasional species and the composition of families, genera and species of the plant community show a unimodal pattern of increasing first and then decreasing. The dominant species of the community has obvious turnover along the elevational gradient, and the middle elevation shows the transitional nature of broad-leaved oak and coniferous fir forests. (2) The overall structure of DBH size class of all woody plant individuals generally shows an inverse “J” type. In terms of elevation, except for the bimodal distribution of woody plants at 1,600 m and 2,000 m, the rest of the elevation showed an inverted “J” shape, and the community structure is generally more stable. The spatial point pattern of dominant species at different elevations shows an aggregated distribution within the 1-10 m scale, which gradually changes to random and uniform distribution as the scale increased. With increasing elevation and removal of habitat heterogeneity, the scale range of aggregated distributions decreases and the scale range of random distributions increases. (3) In increasing elevation species richness shows a significant unimodal distribution pattern with the peak occurring between 1,200 m and 1,400 m. Changes in Shannon-Wiener diversity index, Simpson dominance index, Pielou evenness index along the elevational gradient shows a significant bimodal pattern, with both peaks occurring in 1,000-1,200 m, and 2,000-2,200 m. β diversity (Bray-Curtis index and Jaccard index) shows a unimodal trend along the elevational gradient.

Conclusion: Our study forms the foundation for the construction of long-term monitoring and a basic database of forests in the subtropical-warm temperate transition zone. This research provides a theoretical basis for the conservation of biodiversity in this transition zone and for sustainable forest management.

Aims: Functional differences between species play a vital role in enabling plant species to coexist within an ecosystem. An example of this phenomenon is the vertical stratification of tree communities within a forest, whereby the upper-layer of trees (i.e., canopy) exhibit different ecological structures and functions than the lower-layer of trees (i.e., understory). To identify specific structural and function differences between these communities, we analyzed how upper-layer trees in a subtropical forest impacted lower-layer trees. We further analyzed how these traits changed after a typhoon impacted these communities.

Methods: To perform these analyses, we measured 20 unique plant functional traits (e.g., maximum area-based leaf carbon assimilation rate and instantaneous water use efficiency), structural characteristics (e.g., species abundance and evenness) and functional characteristics (e.g., relative growth rate and mortality rate) for upper- and lower-layer tree communities within a 20-ha forest dynamics plot in a subtropical, evergreen broad-leaved forest in the Dinghushan National Nature Reserve of Guangdong Province, China. To control for spatial autocorrelation (dependence) between the upper- and lower-layers within each plot, Lee’s L statistic was used to characterize how similar the spatial clustering patterns were for functional traits across these layers, as well as for functional traits of the upper-layer communities and structural or functional characteristic of the lower-layer communities. To quantify how the functional traits of the upper-layer communities impacted the structural and functional characteristic in the lower-layer communities, multivariate spatial autoregressive models were utilized, revealing the relative importance of each trait. Finally, we tested how a typhoon affected these relationships by incorporating data into the multivariate regression model prior to and after the typhoon occurred.

Results: Variations in functional traits of the upper-layer trees explained most variations in the structural and functional characteristics of the lower-layer. The spatial structure and the efficiency of photosynthesis and water use in upper-layer trees significantly affected the structure and function of the lower-layer. In particular, as tree species in the upper-layer captured more light, those in the lower-layer were less abundant, rich, and diverse, and their growth rate and recruitment decreased. Conversely, when species in the upper-layer were utilized more water, those in the lower-layer more abundant, rich, and diverse, and their growth rate and recruitment increased. Additionally, the maximum area-based leaf carbon assimilation rate, leaf area, fresh leaf weight, petiole diameter, and xylem specific conductivity of leaves for species in the upper-layer strongly influenced the structure and function of species in the lower-layer. Finally, the typhoon altered the vertical structure of these communities, leading to a corresponding change in how the upper-layer of community impacted the structure and function of the lower-layer.

Conclusion: Our research demonstrated that the vertical structure of subtropical tree communities significantly impact the structure and function of these communities.

Aims: Mountain ecosystems are vital hotspots for global biodiversity. However, climate change and human activities pose significant threats to these ecosystems, leading to alarming transformations. It is essential to monitor changes in these delicate mountain environments, both in terms of biodiversity patterns and fluctuations, in a timely and precise manner. Such monitoring not only advances scientific understanding of species dynamics, but also informs the crucial conservation efforts needed to preserve these vital habitats.

Methods: This study proposed constructing a continuous elevational transect across mountainous terrain as an ideal framework for understanding and predicting the impacts of climate change on mountain biodiversity. We implemented this approach in the Baishanzu region, Qianjiangyuan-Baishanzu National Park candidate area. Along this transect, we examined the flora, species composition, community structure, and diversity patterns of plant communities in relation to the steady changes in altitude.

Results: As elevation increased, the proportion of temperate genera gradually increased, while the proportions of both evergreen species and individuals decreased, although evergreens remined dominated overall. The average tree heights and the maximum tree height of the forest community peaked at approximately altitude of 1,600 m. Species richness and phylogenetic diversity reached their highest points around 1,200 m, displaying a unimodal trend on a broad scale. Other diversity indices, including the Shannon-Wiener diversity index, declined with elevation. Finally, this study also highlighted the unique advantages, recognized limitations, and future development potential of utilizing a continuous elevational transect.

Conclusion: Continuous elevational transects have the potential to be a valuable supplement to existing mountain diversity monitoring systems. They may provide deeper insights into the temporal and spatial shifts in biodiversity within mountain biodiversity forest ecosystems over time.

Aims: Beta diversity measures the pattern of spatial and temporal changes in species composition. The factors driving beta diversity, such as spatial distance and environment conditions, are key topics in ecological research. However, as an important characteristic parameter of forest community, the driving effect of forest stand structure in shaping woody plants beta diversity remains largely unexplored. This study aims to address the contribution of forest stand structure, alongside space and environment, to beta diversity and its components.

Methods: Focusing on woody plants in the 20 ha tropical seasonal rainforest dynamics plot in Nabanhe, Yunnan, this study decomposed beta diversity into two components: Species turnover and species richness difference, across different sampling scales. By using multivariate regression based on distance matrices and variance partitioning, we revealed the relative contributions of spatial, environmental, and forest stand structure factors in shaping beta diversity and its two components.

Results: The results showed that: (1) beta diversity and its species turnover component and species richness difference component decreased with the increase increasing sampling scale, with species turnover consistently dominating beta diversity. (2) Environmental distance had a relatively high explanatory power for beta diversity and its species turnover component, with its influence increasing from 8.8% to 23.9% for beta diversity and from 5.1% to 26.5% for species turnover as the sampling scale expanded. However, environmental distance had little effect on species richness difference component. (3) Forest stand structure demonstrated relatively high explanatory power for beta diversity (11.3%‒25.1%) and maintained a certain degree of explanatory power for both species turnover component and species richness difference component across all scales. At the same time, pure spatial distance, whether or not stand structure was included, had a low explanatory power for beta diversity and its components.

Conclusion: This study supports the viewpoint that the relative importance of environmental filtering in beta diversity, particularly the species turnover component, increases with sampling scale. In contrast, dispersal limitation plays a limited role at local scales. This study further reveals that forest stand structure indicating the light availability and heterogeneity is also an important driving force for beta diversity, similar to environmental factors such as topography and soil. Future research should focus on elucidating the mechanisms by which stand structure influence woody plant beta diversity in the future.

Aims: Non-structural carbohydrates (NSC) serve as a crucial indicator for plant carbon balance and their response to external environmental changes. This study aims to elucidate the spatial variability of NSC and its ecological drivers in dominant plant species within the northern tropical karst seasonal rainforest.

Methods: This study analyzed the leaf NSC content and its components (soluble sugars and starch) in 165 individuals across 31 dominant tree species in various habitat conditions (depression, middle slope, and peak). A Bayesian phylogenetic mixed-effects model was applied to partition NSC variation into two components related to species phylogeny and unrelated factors. The relationships of these components with topography, soil properties, biotic community characteristics, as well as leaf functional traits were explored.

Results: (1) Significant spatial differences in leaf NSC content and its components were observed, with the peak showing the highest NSC content, followed by the middle slope and the depression having the lowest values. (2) The phylogenetic background of species explained 53.97%, 58.23%, and 57.88% of the total variation in NSC, starch, and soluble sugars, respectively, while ecological factors explained 48.85%, 32.54%, and 32.64% of the total variation in these three components. Notably, ecological factors influenced soluble sugar variation more through phylogenetic pathways (23.15%) and starch variation more through non-phylogenetic pathways (26.89%). (3) Factors such as leaf thickness, wood density, slope aspect (north vs. south), specific leaf area, mean DBH of community, mean elevation, and chlorophyll content had significant positive effects on NSC accumulation. In contrast, the sum of community basal area and total soil carbon exhibited significant negative effects.

Conclusions: The spatial variation in leaf NSC of dominant tree species in karst seasonal rainforests is profoundly influenced by both species’ genetic and evolutionary backgrounds and the integrated effects of ecological factors. This reflects significant adaptive differentiation in carbon acquisition, storage, and utilization strategies among plants in different habitats, providing new insights into carbon cycling mechanisms in karst ecosystems and the adaptation strategies of plants.

Aims: The relationship between biodiversity and aboveground biomass in forests has attracted wide attention under the background of the backdrop of intensified global species loss. However, current research primarily focuses on single aspect of biodiversity, rarely considering species, functional, and structural diversity simultaneously. It still remains unclear which aspects of biodiversity influence changes in aboveground biomass.

Methods: Based on the census data of 1 ha secondary forest plot from Donglingshan in Beijing, we analyzed the correlation between biotic and abiotic factors and aboveground biomass using linear regression model. Additionally, structural equation modeling (SEM) was employed to comprehensively compare the relative impacts of species, functional, and structural diversity on aboveground biomass.

Results: (1) The multiple regression results indicated that plots with higher Pielou evenness index, community weighted mean trait value of specific leaf area (CWM.SLA), DBH Shannon index and stand density had a significant positive impact on aboveground biomass, while functional dispersion (FDis) and elevation had a significant negative impact on aboveground biomass. (2) Structural equation model indicated that stand density and structural diversity, primarily represented by DBH Shannon index, had the greatest total effect on aboveground biomass, followed by elevation, species diversity (Pielou evenness index), and functional diversity (functional dispersion and community weighted mean trait value of specific leaf area).

Conclusion: The study suggests that both the niche complementarity hypothesis and the mass ratio hypothesis jointly explain the aboveground biomass in warm temperate deciduous broad-leaved forests, with the niche complementarity effect caused by stand density and DBH Shannon index. The findings provide strong support for explaining the biodiversity-ecosystem functioning relationship and offer a theoretical basis for the sustainable management and conservation of warm temperate forests, holding significant practical implications.

Aim: Research on forest productivity is of great significance for improving forest ecosystem function. However, most studies focus on the productivity of total trees in forests, with relatively little research on the productivity of sapling trees and adult trees, and rarely discuss the effects of species diversity and community structure on the productivity of sapling trees and adult trees.

Methods: This study is based on tree inventory data collected from 20 ha Donglingshan warm temperate deciduous broad-leaf forest plot. Species richness, coefficient of variation in diameter at breast height (DBHcv), and soil nutrients were calculated. We utilized regression models and structural equation models to examine the effects of these factors on productivity of total trees, sapling trees, and adult trees.

Results: For productivity of total trees, initial biomass of total trees, total tree species richness, and soil nutrients had significant positive effects, while DBHcv had a significant negative effect. For productivity of sapling trees, initial biomass of sapling trees, sapling tree species richness, and DBHcv had significant positive effects, while total tree species richness and soil nutrients had no significant impact. As soil nutrients increased, sapling tree species richness had a significant positive effect on productivity. For productivity of adult trees, initial biomass of adult trees, total tree species richness, and soil nutrients had significant positive effects, while DBHcv had a significant negative effect and adult tree species richness had no significant effect. As soil nutrients increased, adult tree species richness had a significant negative effect on productivity. The effects of species diversity, community structure and soil nutrients on productivity of adult trees were similar to those on productivity of total trees, but different in sapling trees.

Conclusion: Our study demonstrates that the effects of species diversity, community structure, and soil nutrients on productivity of trees vary across different life history stages. Both the niche complementarity effect hypothesis and the vegetation quantity hypothesis can well explain the increase of forest productivity. This study provides a theoretical basis for the management practices of trees in different life history stages and will have important implications for forest tending in warm temperate secondary forests.

Aims: Soil fauna are essential biological drivers of litter decomposition, playing an irreplaceable role in promoting nutrient cycling, maintaining soil structure stability, and enhancing ecosystem functions. However, due to the high diversity of soil fauna groups and their complex interspecific interactions, the relationship between their community characteristics and litter decomposition rates remains uncertain. Meanwhile, the leaf economics spectrum, which reflects the trade-off between resource acquisition and utilization strategies, may directly or indirectly affect the structure and functions of soil fauna communities. Here, we aim to explore the mechanisms by which different soil fauna groups affect litter decomposition and potential regulatory role of the leaf economics spectrum on soil fauna communities.

Methods: This study selected 20 representative plant litters from the subtropical Badagongshan region, Hunan, China. The leaf economics spectrum was constructed based on its core functional traits, and a 13-month litter decomposition experiment was conducted using mesh bags with three different mesh sizes (0.07 mm, 2 mm, and 5 mm) to investigate the effects of soil fauna body size on litter decomposition.

Results: The results showed that a total of 28,786 individuals were collected, belonging to 11 classes and 29 orders. Mites and Collembola were the dominant groups, accounting for over 80% of the total soil fauna. Litter species significantly affected soil fauna density and richness, but had no significant effects on the Shannon-Wiener diversity index, Gini-Simpson index, or Pielou evenness index. The leaf economics spectrum derived from litter traits was not correlated with soil fauna abundance or diversity. Soil fauna significantly increased the litter decomposition rates, contributing up to 45.28% of the total decomposition. Contributions varied across body size groups, with micro- and mesofauna accounting for 28.31% of the decomposition. When all body size groups of soil fauna were present, litter decomposition rates showed significant correlations with faunal abundance and diversity.

Conclusion: We demonstrated that litter species affect soil fauna abundance. The community characteristics of soil fauna promote litter decomposition and transformation. Different body size groups regulate decomposition rates to varying extents. This study contributes to a deeper understanding of the interaction between soil fauna and litter decomposition, and provides scientific evidence for forest ecosystem management aimed at enhancing nutrient cycling and conserving soil biodiversity.

Aims: Litter constitutes a crucial component of forest ecosystems, playing significant roles in biogeochemical cycling, energy flow, and nutrient balance. Nevertheless, understanding the mechanisms by which biotic and abiotic factors influence litter production in heterogeneous natural forest ecosystems remains contentious. This study aims to investigate the long-term dynamics and influential factors affecting litter production in karst forests within subtropical regions.

Methods: In this study, we set up 151 litter traps, and collected litter monthly from 2018 to 2022 in a 25-ha karst evergreen and deciduous broad-leaved mixed forest dynamics plot in the Mulun National Nature Reserve, Guangxi Province. All litter in each trap was dried, classified and weighed.

Results: The average annual litter production in karst forests was 5,946.55 ± 77.27 kg/ha, with significant inter-annual variability. The proportion of each litter component ranked as follows: leaves (63.26%) > debris (24.89%) > twigs (12.79%). Seasonal patterns for total litter and leaf litter production were similar, displaying a bimodal trend with peaks in spring (March-April) and fall (September-October). Monthly dynamics of branch litter followed a unimodal pattern, peaking in autumn (around October), while debris showed a bimodal pattern with peaks in spring (May) and fall (October), respectively. The species diversity, convexity, mean diameter at breast height (DBH), were the main driving factors of litter production within a 5 m radius neighborhood around the traps. The results of the structural equation model indicated that the species diversity, DBH, and convexity have a direct influence on the total litter production, while slope had an indirect influence on the total litter production through altering species diversity.

Conclusion: Five years of continuous monitoring have revealed significant seasonal variations in litter production within the karst evergreen and deciduous broad-leaved mixed forest. Both biotic and topographic factors collectively affected the spatial variability of litter production.

Aim: This study aims to investigate community patterns in the 25-ha dynamics plot of subtropical forest in Baishanzu, Zhejiang Province, and their relationship with environmental factors affecting woody plant sexual systems. The broader theoretical goal is to explore the impact of plant sexual system diversity on forest community assembly.

Method: This study conducted a comprehensive survey of all woody plants with a stem diameter at breast height (DBH) ≥ 1 cm in the 25-ha dynamics plot of the Baishanzu (BSZ) forest in Qingyuan County, Zhejiang Province. We analyzed the abundance of different plant sexual systems, the DBH of species within each sexual system, the importance of each sexual system within the community, and the diversity of sexual systems within the plot. Additionally, redundancy analysis (RDA) was employed to quantitatively examine the influence of topography, soil physicochemical properties, and succession on the characteristics of different plant sexual systems.

Results: (1) Among the 163 species of woody plants in the 25-ha plot, 95 were hermaphrodite, 43 were dioecy, and 25 were monoecy. Hermaphrodite exhibited dominance in quantitative characteristics at the family, genus, species, and individual levels. The average DBH of monoecy was significantly greater than that of hermaphrodite and dioecy. (2) At the quadrat level, hermaphrodite remained dominant, followed by dioecy and monoecy. The north-facing slope at higher elevation exhibited lower sexual system diversity, while the south-facing slope at lower elevation exhibited higher sexual system diversity. (3) The impact of topography on plant sexual systems surpassed that of soil physicochemical properties. Additionally, the succession stage significantly influenced the quantitative characteristics of plant sexual systems, with early successional areas exhibiting higher occurrences of dioecy and consequently greater sexual system diversity.

Conclusion: The sexual systems of plants play an important role in forest community assembly in the BSZ 25-ha plot. Topography, soil physicochemical properties, and succession jointly shape the diversity of plant sexual systems in the forest community.

Aims: Nitrogen deposition, an important factor driving the biodiversity change of forest ecosystems, has been a major influence of change in the global environment. Although many studies have confirmed that nitrogen intervention can significantly alter understory population density and species diversity in the forest community, most of these studies are limited to herbaceous plants. The seedling stage of woody plants, as the key period of forest regeneration, is rarely discussed in terms of the dynamics of nitrogen addition and its response mechanisms. In this study, we aim to test the effects of nitrogen addition on seedling dynamics and explore the mechanism of nitrogen addition on species diversity with negative density dependence.

Methods: This study was based on a manipulative experiment of nitrogen addition in the Changbai Mountain broad- leaved Korean pine mixed forest. Four nitrogen addition levels were set: Control (unadded), low nitrogen (25 kg∙ha·yr^‒1), medium nitrogen (50 kg∙ha·yr^‒1), and high nitrogen (75 kg∙ha·yr^‒1).

Results: Our results indicated that nitrogen addition promoted a similarity of interannual seedling dynamics, and significantly decreased the community-level seedling density and recruitment. Also, under low nitrogen level treatment, species richness and Shannon-Wiener index were significantly lower than those of the control group but increased significantly under medium and high nitrogen levels. In addition, the conspecific negative density dependence of the seedling was intensified with an increase in nitrogen concentration, and was simultaneously negatively correlated with species richness, Shannon-Wiener, and evenness index, verifying the potential pathway in which nitrogen deposition could change species diversity by influencing the conspecific negative density dependence.

Conclusions: This study demonstrated the effects of nitrogen addition on seedling dynamics in the temperate broad-leaved Korean pine mixed forest on Changbai Mountain and confirmed the mechanism of nitrogen addition on species diversity from the perspective of negative density dependence. These results reveal the dynamics and interconnectivities of temperate forest seedlings and nitrogen deposition.

Aims: Studying the dynamic changes in secondary evergreen broad-leaved forests is crucial for understanding the formation and maintenance of these forest communities. This study aimed to investigate the dynamic changes in a subtropical secondary evergreen broad-leaved forest, providing a scientific basis for developing forest conservation and restoration strategies.

Methods: We selected a 9 ha subtropical secondary evergreen broad-leaved forest dynamics plot in the Wuyanling National Nature Reserve, Zhejiang Province, as the research site. We conducted thorough surveys of woody plants with a diameter at breast height (DBH) ≥ 1 cm in 2013, 2018, and 2023. We analyzed and compared the changes in community composition, structure, and dynamics over these years.

Results: (1) Over the past 10 years, the top 10 species by importance value within the plot have remained unchanged. However, there has been a significant decline in plant species diversity and abundance, with some rare species disappearing. (2) The proportion of small-diameter individuals decreased, while the proportions of medium-diameter and large-diameter individuals gradually increased. The proportions of plant individuals across different leaf life forms and habitats have remained relatively stable. (3) The mortality rate of plants decreased with increasing diameter and varied across different habitats. (4) Compared to the period from 2013 to 2018, the overall plant mortality rate decreased during the period from 2018 to 2023, and the recruitment rate sharply declined.

Conclusion: In the late succession stage of the 9 ha secondary evergreen broad-leaved forest dynamics plot at Wuyanling, the stability and competitive advantages of dominant species have led to a gradual decrease in diversity and the abundance of individual trees, with some rare species disappearing. The decreasing proportion of small-diameter individuals and the lower mortality rate suggest that the community is transitioning into a mature stage of succession. However, the sharp decline in the recruitment rate of plants within the plot indicates that the community’ development faces significant challenges.

Aims: Sprouting regeneration is a key mode in forest renewal, playing a crucial role in individual survival, population continuity, and maintaining biodiversity within plant communities. However, evidence is limited regarding whether sprouting characteristics significantly vary across different functional plant groups in response to topographic factors. This study aimed to explore the sprouting characteristics of woody plants in subtropical semi-humid evergreen broad-leaved forests, analyze their responses to topographic factors, and enhance understanding of forest regeneration processes.

Methods: We conducted the study in a 20-ha forest dynamics plot in the subtropical semi-humid evergreen broad-leaved forest of the Jizu Mountains, Yunnan. We first calculated sprouting metrics for woody plants with a diameter at breast height (DBH) ≥ 1 cm, including the sprouting ratio, sprouting stem ratio, basal sprouting ratio, and basal sprouting stem ratio at both the species and community levels. The Wilcoxon rank-sum test was applied to analyze differences in sprouting ability among functional groups. Finally, we used linear mixed models to examine the correlation between sprouting ability and topography factors.

Results: (1) Out of 63 woody plant species observed, 68.5% exhibited sprouting behavior, with 64.1% showing basal sprouting. A total of 9,668 individuals sprouted, with 6,778 exhibiting basal sprouting, representing 22.0% and 15.4% of the total plant individuals, respectively. (2) Plants in the tree layer had the highest sprouting ratio, followed by the sub-tree layer. The sprouting stem ratio and basal sprouting ratio was significantly higher in the tree and sub-tree layer, while the shrub layer had the lowest. The basal sprouting stem ratio were significantly higher in the sub-tree layer compared to the shrub layers. Evergreen species displayed significantly higher sprouting indicators than deciduous species. (3) In the tree layer, the basal sprouting ratio and basal sprouting stems ratio were positively correlated with elevation. In the sub-tree layer, the sprouting ratio was significantly correlated with convexity, while the sprouting stem ratio was significantly correlated with convexity and slope. No significant correlation was found between topographic factors and sprouting ability of shrub layer, and the sprouting ability of evergreen species was primarily influenced by convexity, while deciduous species were more influenced by elevation and slope.

Conclusion: The results of our study reveal that sprouting regeneration is prevalent among woody plants in subtropical semi-humid evergreen broad-leaved forests and is largely affected by topographic factors. In addition, plant sprouting at different forest layers is regulated by various topographic factors, with deciduous plants being more susceptible to these influences compared to evergreen plants. Therefore, when examining environmental effects on plant sprouting regeneration, it is necessary to consider the variations among functional groups to better understand sprouting regeneration strategies and the ecological mechanisms behind them.

Background & Aim: Ecological uniqueness is a key component of β diversity, primarily quantifying the relative contribution of each sampling site to the total variation in community composition. This concept is of great significance for biodiversity conservation and restoration. Over the past decade, ecological uniqueness has received substantial attention from ecologists and conservation biologists, leading to significant advancements in its quantifications, spatiotemporal patterns, driving mechanisms, ecological functions, and applications in biodiversity conservation. We first summarized the main methods for calculating ecological uniqueness, we then conducted a systematic review of literatures on taxonomic ecological uniqueness from 2013 to 2023. Furthermore, we elaborated on its spatiotemporal patterns and underlying mechanisms. Moreover, we explored the potential impact of ecological uniqueness on ecosystem functioning and its implications for biodiversity conservation.

Review Results: Ecological uniqueness can primarily be calculated using community composition datasets or dissimilarity matrices. Studies on ecological uniqueness are predominantly concentrated in Europe, America, and Asia, focusing mainly on animal and plant groups. Moreover, the literature reviews several key findings: (1) Ecological uniqueness exhibits clear latitudinal or elevational gradients, though these patterns differences among different biological groups and study regions. (2) Multiple abiotic and biotic factors, such as climate, soil, and community characteristics, significantly shape the ecological uniqueness of different biological groups by influencing species range size, community richness and species compositions. (3) Ecological uniqueness can promote or decrease ecosystem functioning, depending on combinations of species or the proportions of specific groups present. (4) Regions with higher ecological uniqueness often harbor a higher proportion of rare or endangered species, contributing significantly to regional biodiversity. These regions are typically considered as key areas for biodiversity conservation.

Perspectives: This review also discusses the directions of future research on ecological uniqueness, with particular emphasis on: (1) Conducting in-depth researches on multidimensional (taxonomic, functional, and phylogenetic) ecological uniqueness; (2) Focusing on the patterns and driving mechanisms of ecological uniqueness across different spatiotemporal scales; (3) Applying new technologies and methods for future assessment of ecological uniqueness.

Species diversity is an important indicator of community structure, composition and function of forests. Evaluating and monitoring changes in species diversity of forest communities are crucial for natural resource management and conservation effectiveness, providing important support for scientific research, policy-making, and ecological conservation. The Qianjiangyuan-Baishanzu National Park candidate area is located within a priority area for biodiversity conservation in China, preserving contiguous large-area mid-subtropical low-altitude evergreen broad-leaved old-growth forests that exemplify typical, integrity, and nationally representative characteristics. The Zhejiang Qianjiangyuan Forest Biodiversity National Observation and Research Station (hereinafter referred to as “Qianjiangyuan Station”) established a 24-ha forest dynamics plot within the Gutianshan area (formerly the Gutianshan National Nature Reserve) of the Qianjiangyuan section, which is part of the Qianjiangyuan-Baishanzu National Park candidate area following ForestGEO protocols during 2004-2005. The plot provides an ideal platform for long-term monitoring of species diversity in subtropical evergreen broad-leaved forest communities. This study is based on four censuses organized by the Qianjiangyuan Station in 2005, 2010, 2015, and 2020 on the 24-ha subtropical evergreen broad-leaved forest dynamics plot in Gutianshan. We conducted data quality control assessments and statistical analyses of census data for all stems with diameters at breast height (DBH) ≥ 1 cm of woody species. The study provides species diversity data for 600 quadrats of 20 m × 20 m scale. It calculates community α diversity indices (species richness, Shannon-Wiener diversity index, and Pielou evenness index) and β diversity (Jaccard index) were calculated for each quadrat. These data offer a foundational basis for in-depth research into biodiversity, community structure, and functions in the subtropical forest communities of Gutianshan. Furthermore, these data support evaluations of biodiversity conservation effectiveness and adaptive management strategies in this national park.

Database/Dataset Profile