Plant functional traits help us understand forest carbon storage. We quantified eight functional traits that reflect plant life history strategies: leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf carbon (LC), nitrogen (LN), phosphorus (LP), leaf carbon-nitrogen ratio (LCNR), and wood density (WD). But their role across successional stages is still unclear. We set up sixteen permanent plots in Pu'er, Yunnan, China. Each plot was 60 m & times; 60 m. The plots covered four successional stages. Stage one was early-successional Simao pine forests. Stage two was mid-successional mixed forests. Stage three was mid-to-late-successional mature mixed forests. Stage four was late-successional mature broad-leaved forests. We measured aboveground carbon storage (CS). We measured carbon growth rates (CAR). We also measured plant traits, soil nutrients, and topography. Carbon storage increased step by step during succession. It became stable in the late stage. Carbon accumulation rate stayed similar across all stages. A key trait axis (LPC2) directly increased carbon storage. LPC2 represents the trade-off between nitrogen use efficiency and leaf construction costs. Environmental factors only affected carbon storage indirectly. They influenced traits first. These results support the metabolic trade-off hypothesis. They also support the leaf economics spectrum theory. Early-successional traits help forests gain biomass quickly. Late-successional traits help forests store carbon for a long time. We suggest protecting mature forests. We also suggest using pioneer species in restoration. This dual strategy can enhance carbon sequestration in subtropical production forests.

Although competition and facilitation both influence tree diversity1-5, their relative importance and variation with latitude remain poorly understood. Using data from 17 large forest plots, including around 2.7 million trees and over 5,400 species spanning 5° S to 47° N, we quantified the latitudinal trends of the relative importance of negative (competitive) and positive (facilitative) interactions among neighbouring tree species, accounting for three biotic and eight environmental factors. We examined whether the average neighbourhood species diversity around individuals of each focal species was larger or smaller than expected under null models. The results show that negative interspecific interactions prevailed across most plots. Near the equator, the relative proportions of species surrounded by a lower or higher than expected number of neighbours were roughly equal, but at higher latitudes, the proportions of species with a relatively higher number of neighbours declined, and those with fewer neighbours increased significantly. This latitudinal pattern can be attributed in part to reduced abundance of legumes, non-arbuscular mycorrhizal associations, and the weaker canopy nursing effect towards higher latitudes, but it was mediated by mean annual temperature. These findings reveal a previously unrecognized relative decline in facilitative interactions and increase in competitive interactions with latitude and suggest that rising temperatures could enhance facilitative effects and promote tree community diversity at higher latitudes.

IntroductionAccurately assessing the natural recovery processes of forest ecosystems remains a key challenge in restoration ecology. The concept of dark diversity—the set of species absent from a site but belonging to its habitat-specific species pool—provides a novel lens for this assessment.MethodsIn this study, we developed and applied an integrated diagnostic framework that synthesizes dark diversity, functional traits, and diagnostic species. We applied this framework to a chronosequence of recovering forest ecosystems in subtropical China, representing early, middle, and late recovery stages.ResultsOur results demonstrated that the Community Completeness Index (CCI), derived from dark diversity, increased significantly during recovery, with its stabilization indicating the approach to a stable state. The framework identified stagespecific early-warning species: the absence of light-demanding, acquisitive transitional species in the mid-stage signaled successful progression, while the absence of shade-tolerant, conservative climax species in the late-stage signaled potential degradation. Crucially, analysis using Dark Diversity Affinity (DDA) revealed that the functional traits of species (e.g., seed mass, mycorrhizal type, leaf economics) were the primary filters determining species absence, exhibiting a stronger influence than local environmental conditions. These filters shifted predictably across stages, from dispersal and establishment limitations early on to competitive interactions later.DiscussionThe proposed framework translates dark diversity theory into an actionable tool for restoration. It moves beyond simple observation to diagnose recovery success, pinpoint specific bottlenecks, and inform targeted interventions such as assisted dispersal or canopy management. This provides a mechanism-based approach for guiding precision restoration in forest ecosystems.

IntroductionBiodiversity has a significant impact on the formation and maintenance of ecosystem functions, and its role changes dynamically along with the ecological succession process. However, the relative contributions of biodiversity across different dimensions to ecosystem functions, as well as the patterns of change in these contributions during succession processes, remain unclear.MethodsThis study selected four succession stages of monsoon evergreen broad-leaved forests (early succession, early-to-mid succession, mid-to-late succession, and late succession) as research subjects. Based on vegetation survey data, we calculated three biodiversity metrics (taxonomic diversity, functional diversity, phylogenetic diversity) and functional composition. Using forest productivity as an indicator of ecosystem function, we employed structural equation modeling to analyze how biodiversity across different dimensions at various succession stages influences productivity. This investigation explores how the relative contributions of selection effects, niche complementarity, and mass ratio effects to productivity change throughout forest succession. ResultsThe results indicate that: (1) As succession progresses, species richness, functional dispersion, and the phylogenetic PD index exhibit a unimodal pattern. Functional traits predominantly reflect resource acquisition in the early stages, shifting towards conservation in the later stages. Productivity shows fluctuating trends(P < 0.05); (2) The relationship between biodiversity and productivity changes with succession, showing an overall downward trend; (3) In the early succession stage, productivity is primarily driven by the mass ratio effect. During the middle to early succession stage, it is jointly driven by the selection effect and the niche complementarity effect. In the middle to late succession stage, it is mainly driven by the complementarity effect. There is no significant correlation between the late succession stage and biodiversity. Additionally, the local environment also has a significant impact on productivity. DiscussionThe research findings are expected to provide scientific evidence for understanding the formation and maintenance patterns of monsoon evergreen broad-leaved forest ecosystem functions.

The analysis of carbon dynamics in old-growth forests helps us understand forest conservation, restoration, and regional carbon sequestration. There is still controversy over whether old-growth forests are carbon sources or sinks. Studying the carbon storage and dynamics of old-growth forests is of great significance for evaluating their carbon source and sink functions, as well as quantifying forest carbon fixation at the regional scale. Based on the dynamic monitoring data of the old-growth forest in the Taiyanghe River Provincial Nature Reserve in Yunnan Pro-vince in 2014 and 2024, we investigated the biomass and carbon storage of tree layer in the old-growth forest, as well as their distribution characteristics in different diameter classes and organs by using principal component analysis and random forest model. We also analyzed the dynamics of carbon storage and their influencing factors. The results showed that the total biomass of the tree layer in 2014 and 2024 were 359.72 and 449.44 t·hm-2, respectively, and the total carbon storage was 179.86 and 224.72 t·hm-2, respectively, showing an upward trend and demonstrating good carbon sequestration function. The carbon storage of large trees (diameter at breast height≥22.5 cm) in 2024 (188.96 t·hm-2) was significantly higher than that in 2014 (143.69 t·hm-2), and the proportion of total carbon storage in the tree layer increased from 79.9% to 84.1%. In both surveys, carbon in the tree layer was mainly distributed in the trunk, followed by branches and roots, with leaves having the lowest carbon content. There was a positive correlation between species diversity and the carbon storage of the tree layer. The biomass of large trees, as the main driving factor for changes in carbon storage in the tree layer of aging forests, had variance explanatory rates of 10.1% and 13.6% in 2014 and 2024, respectively. During the monitoring period, the relative importance of driving factors for carbon storage in the old-growth forest tree layer changed: the explanatory power of the coefficient of variation of large tree diameter at breast height and altitude increased, while the explanatory power of species diversity significantly decreased from 13.3% to 2.6%. Overall, the tree layer of the old-growth forest in the study area serves as a carbon sink, with large trees dominating the dynamic changes in carbon storage.

A thorough understanding of tree growth responses to drought across temperature and moisture gradients is crucial for assessing forest health and growth dynamics under ongoing climate change. This study investigated the growth-climate responses of Pinus yunnanensis and its resilience to drought with varying intensities across four distinct climate zones (hot-dry, warm, cold-dry, and humid) on the Yunnan Plateau, southwestern China. The radial growth of P. yunnanensis exhibited stronger moisture limitations and greater drought susceptibility in hot-dry and warm regions compared to cold-dry and humid regions. Severe drought during the main growing season diminished growth resistance and resilience, particularly in hot-dry regions. In contrast, drought during the early growing season had a positive effect on tree recovery and resilience in warmer regions. Post-drought growth recovery varied across climate zones, with a longer recovery time in drier regions compared to wetter regions. The sensitivity of growth to seasonal climate affects growth resilience, particularly in xeric areas. With increased moisture restrictions, the effects of seasonal temperature sensitivity on growth resilience were gradually being replaced by the early growing season moisture sensitivity. These findings improve our understanding of the habitat-specific growth resilience of P. yunnanensis to extreme drought events and provide quantitative guidance for implementing forest management strategies in the context of regional climate change.

Aims Seedlings play a crucial role in the conservation of forest biodiversity.Previous studies have paid little attention to seedling communities in monsoon broadleaf evergreen forests in Pu'er,Yunnan.Our aim was to investigate the mechanisms of seedling community assembly there. Methods We analyzed the species composition of the seedling community based on the seedling survey in a 30 hm2 forest dynamics plot.Seedling plots are divided into different groups according to the dominant species.The stepwise community assembly model(STEPCAM)was used to investigate the mechanisms of community assembly and to further analyze the functional traits of seedling communities. Important findings Castanopsis echidnocarpa and C.calathiformis are the dominant seedling species in the monsoon broadleaf evergreen forest.Four plot types(i.e.,C.echidnocarpa plot,C.calathiformis plot,mixed-dominant species plot,non-dominant species plot)were classified according to the presence or absence of dominant species.The seedling community assembly processes included:a)random dispersal assembly(with contribution rate 43.1％-61.3％);b)habitat filtering(with contribution rate 27.4％-33.9％);and c)limiting similarity(with contribution rate 5.7％-27.2％).The C.echidnocarpa and C.calathiformis plots were dominated by deterministic processes,with 56.9％and 54.6％contributions respectively,whereas the mixed-dominant and non-dominant species plots were dominated by stochastic processes,with 60.4％and 61.3％contributions respectively.Rao's quadratic entropy(Rao'Q)was highest in the non-dominant species plot and lowest in the mixed-dominant species plot.The C.echidnocarpa plot has the lowest specific leaf area(SLA)and higher leaf thickness(LT),specific stem length(SSL),root mass fraction(RMF)and a maximum potential plant height(PPH),while the C.calathiformis plot and non-dominant species plot have a higher SLA.Among different seedling plots,the coefficients of variation for SSL and PPH were higher,while the coefficients of variation for other functional traits were lower.Multiple regression analysis showed that SLA and PPH were significantly and positively correlated with Rao'Q in different seedling plots.LT and life form were significantly and positively correlated with Rao'Q in other three types of plots,except for the non-dominant species plot.Thus,seedling community assembly in the monsoon broadleaf evergreen forest is driven by both stochastic and deterministic processes,and the contribution of the two processes varies with the type of seedling communities.

IntroductionRevealing the spatial distribution pattern and formation mechanism of species in a community can provide important clues for community renewal, succession, and diversity maintenance mechanisms.MethodsIn this study, we employed spatial point process modeling to identify and quantify the processes contributing to the spatial distribution of species. Simultaneously, we explored the relationship between functional traits and species spatial distribution characteristics in conjunction with phylogenetic studies.ResultsThe results revealed that the LGCP model effectively described all species, indicating that the spatial pattern of species may be influenced by a combination of environmental filtering and dispersal limitation. Disparities in species spatial distribution were elucidated by characterizing functional traits, such as body size and resource conservation. Incorporating phylogenetic information enhanced the predictive capacity of functional traits in explaining species spatial distribution.DiscussionThis study underscores the significance of the joint effects of environmental filtering and dispersal limitation in generating species spatial distribution patterns. Integrating spatial point process models with considerations of functional traits and phylogeny proves to be an effective approach for comprehending the mechanisms governing species combinations.

Plants and soil bacteria exert a vital function in mediating soil ecosystem multifunctionality (EMF). Nevertheless, plant and soil bacteria interaction during forest secondary succession is poorly understood, and their roles in soil EMF remain largely unexplored. The dynamics of soil physicochemical properties and bacterial diversity was studied in southwest China during forest succession from coniferous to monsoon broadleaf evergreen. Interdomain ecological networks (IDEN) were adopted for investigating plant-bacteria associations. With the purpose of assessing how soil factors, bacterial community and plant diversity influenced soil EMF, the structural equation model (SEM) was used. It was discovered that both soil bacterial diversity and soil EMF gradually increased with the succession. IDEN analysis revealed that plant-bacteria ecological networks differed significantly across successional stages. Keystone plant species richness (KSR) increased with succession, which benefited soil bacteria diversity (path coefficient = 0.802, p < 0.001) while having a direct negative impact on pH (path coefficient = -0.602, p < 0.05) and C:N (path coefficient = -0.759, p < 0.001). Soil pH and C:N ratio declines were observed during forest secondary succession and were found to be inversely related to soil EMF. Furthermore, soil pH was found to be inversely related to bacterial diversity. The SEM analysis explained 88.2% of the variation in soil multifunctionality. The findings suggested that keystone plant species played a key function in regulating the variations of soil bacterial community and EMF (total effect = 0.813). Our study clarified the critical functions of keystone species in driving soil bacterial diversity and multifunctionality during forest succession and provided a new perspective on the relationship between above- and below-ground.

Introduction Scale dependencies play a vital role in defining the biodiversity-ecosystem functioning relationship in forest ecosystems, which varies based on the magnitude of multiple plant diversity attributes, soil properties, and aboveground biomass in forest ecosystems. However, the effects of plant diversity and big-sized trees on the relationship between plant diversity and aboveground biomass across different scales remain unclear in forest ecosystems. Methods Based on a 30-ha tropical montane evergreen broad-leaved forest dynamics plot in Yunnan province, China, we comparatively analyzed the importance of scale-dependent effects of multiple plant diversity attributes, soil properties, neighborhood competition intensity and aboveground biomass of big-sized trees, as well as stand structural complexity on aboveground biomass of all woody individuals. The aim is therefore to identify the main predictors for sustaining aboveground biomass of all woody individuals, considering multiple biotic and abiotic factors jointly, as well as underlying mechanisms. Results Our results suggest that indicators such as species richness and phylogenetic diversity did not strongly contribute to aboveground biomass of all woody individuals with increasing spatial scales, while aboveground biomass of big-sized trees exhibited the greatest contribution to aboveground biomass of all woody individuals. Stand structural complexity, characterized by variances in woody plant diameter at breast height, also contributed more to aboveground biomass of all woody individuals indirectly via neighborhood competition intensity and aboveground biomass of big-sized trees. Contributions of functional dispersion and community-weighted mean of leaf phosphorus concentration to aboveground biomass of all woody individuals became stronger with increasing spatial scales. Neighborhood competition intensity exhibited a negative linear relationship with aboveground biomass of all woody individuals at the smallest scale, but it affected positively aboveground biomass of all woody individuals across spatial scales, likely due to indirect effects via aboveground biomass of big-sized trees. Discussion Big-sized trees will likely become more important in biodiversity maintenance and ecosystem function management as deforestation and forest degradation.

物种的空间分布格局和种群结构受生境过滤、扩散限制、种内和种间相互作用等多重过程的影响.研究物种的空间分布格局、物种关联及其与环境因子的关系,有利于揭示生物多样性维持机制,探索群落稳定演替的生态过程.季风常绿阔叶林作为我国热带-亚热带交错区典型的地带性植被类型,是研究交错区物种空间分布格局的重要平台.本研究基于普洱30 ha季风常绿阔叶林动态监测样地的调查资料,采用点格局分析的方法,对3种不同种子扩散方式的优势种即短刺锥(Castanopsis echidnocarpa)、茶梨(4nneslea fragrans)、西南桦(Betula alnoides)的空间分布格局及其随尺度的变化进行研究,分析了生境过滤和扩散限制对物种空间分布格局的影响以及不同生活史阶段间的种内和种间关联.结果显示:短刺锥和茶梨在山脊和山坡分布居多,而在沟谷较少,西南桦则主要分布于山坡.3种优势种在完全随机模型下所有尺度上均表现为聚集分布,且聚集强度随空间尺度的增大而减小.排除生境异质性后,所有优势种只在小尺度上表现为聚集分布,大尺度上为随机分布或规则分布.扩散限制对短刺锥和茶梨的分布格局影响较小,而对西南桦的分布格局影响较为显著.在种内不同径级的空间关联上,短刺锥和茶梨种内不同生长阶段树木之间存在相关性,但西南桦则相关性不明显;在种间关联上,短刺锥和茶梨为正相关,和西南桦为负相关,茶梨和西南桦则正、负相关都存在.本研究表明,物种的空间分布格局是物种本身属性和环境条件的综合反映,其中生境过滤和扩散限制的关联效应是影响物种空间分布的主要原因.

Pinus yunnanensis forest is a unique forest type in southwest China and one of the main forest types in Yunnan Province, which also has great ecological, economic and social significance. Understanding the changes in the stoichiometric characteristics is a key to study the nutrient cycling, limiting factors and stability mechanisms of the forest ecosystem. However, the stoichiometric characteristics, stability of the ecosystem of P. yunnanensis natural forests and whether they are limited by nutrients are still poorly understood. Based on a K-S test, ANOVA analysis and OLS regression analysis, we analyzed the concentrations of leaf C, N and P in 48 woody species of natural P. yunnanensis forests from 122 plots to explore the pattern of leaf C:N:P stoichiometry. Our results showed that the mean values of leaf C, N and P plus C:N, C:P and N:P for the 48 woody species were 451.12, 11.05 and 1.11 mg/g and 45.03, 496.98 and 11.27, respectively. The coefficients of variation of leaf C, N and P plus C:N, C:P and N:P were 5.29%, 36.75%, 51.53%, 29.63%, 43.46% and 41.68%, respectively. The geometric mean values of leaf N, P and N:P were 10.49 and 1.00 mg/g and 10.51, respectively. Leaf C and N, and C and P relationships showed significant negative correlations, but a significant positive correlation was observed between leaf N and P. There were significant differences in leaf N and C:N across functional groups. There were significant differences in leaf C and P between evergreen and deciduous, conifer and broadleaf trees. Significant differences in leaf C:P were only observed between evergreen and deciduous trees, and significant differences in leaf N:P were observed between conifer and broadleaf trees. The relatively low N:P in all sampled trees indicated that N was a limiting factor in the distribution of natural P. yunnanensis forests. However, the higher leaf C:N and C:P ratios indicated that the P. yunnanensis natural forest ecosystem was in a relatively stable state.

综合世界植被和中国植被的分类进展,以群落外貌、结构、动态、种类组成、成因和生境相结合为依据,提出一个新改进的中国植被分类系统.该分类系统仍坚持将植被型(Vegetation type)、群系(Alliance)和群丛(Associaton)作为植被分类的基本等级,但群系的英文建议用"Alliance",而不用"Formation".植被型以上设置植被纲(Class of vegetation types)、植被亚纲(Subclass of vegetation types)和植被型组(Group of vegetation types)作为辅助分类单位,植被型以下建议不设过多的分类辅助等级.我们将自然植被分类系统的高级分类单位分为3个植被纲,7个植被亚纲,12个植被型组,76个植被型.植被型等级编排了分类代码.新改进的分类系统与中国植被1980分类系统的主要区别是:将冻原、荒漠、沼泽分别作为一种植被类型的生长环境,而非作为一种植被类型来看待,以示与地貌学和自然地理学相关概念区分;新增簇生叶类植被亚纲和相关植被型,将竹类分别归并到森林植被和灌丛植被相关等级;依据草本植物的生态类型、植被成因及其动态,将草本植被分成草原、草甸和草丛3个植被型组.植被命名的方法作为植被分类的重要内容之一,也在文中进行了重点探讨.

Using Landsat remote sensing images in 1990, 2000, 2010 and 2019, land use types in the dry⁃hot valley area of Jinsha River Basin are classified by combining visual interpretation with maximum likelihood, and the spatiotemporal change and transfer process of land use types in the dry⁃hot valley area of Jinsha River Basin are also studied. The InVEST model combining meteorological, soil and topographic data are used to evaluate the water⁃producing and water⁃conserving function of different land use types in the dry⁃hot valley area of Jinsha River Basin from 1990 to 2019. The main conclusions

Background The relative influence of climate change and drought events on tree growth at different altitude and tree ages remains insufficiently understood in the Jinsha River Basin, southwest China, limiting prediction of forest adaptability to high-frequency droughts and climate change. We conducted a dendroecological study to explore and quantify the dominant climate factors that determining radial growth of Pinus yunnanensis trees of different ages and at different altitudes, to evaluate their resilience to drought events. Results Radial growth of P. yunnanensis at high elevations is typically limited by low temperatures, the explanatory rate of temperature factors on growth increased from 23.6–59.7% with altitude. Tree growth at low elevations is more sensitive to moisture factors, the explanatory rate of moisture factors on growth decreased from 76.4–40.3% with altitude. The young and mature trees are more prone to moisture factors than middle-age and near-mature trees, the young and near-mature trees are more prone to temperature factors than middle-age and mature trees. The older trees usually showed less drought resistance and recovery than the young and middle-age trees. The resistance and recovery of P. yunnanensis weakened with the increased frequency of drought events. Tree resistance and resilience was highly dependent on the average pre-drought growth, whereas the recovery showed weak or no significant relationships with average pre-drought growth. Conclusion Our study demonstrates that radial growth of P. yunnanensis trees showed age- and altitude-specific demand for energy and moisture. P. yunnanensis trees at different altitudes and ages are differentially adapted to varying levels of climate stress and display different strategies to withstand the effects of drought with altitude and ages.

全球变化和人类活动正以空前的速度在世界范围内改变着生物多样性,这导致了全球生物多样性的锐减以及生产力的下降、病虫害的增加和抗入侵能力的减弱等生态问题.近30年来,生态学家开始对于生物多样性的持续丧失是否以及如何影响生态系统功能的问题越来越感兴趣,生物多样性与生态系统功能(biodiversity and ecosystem functioning,BEF)关系的研究应运而生,并成为生态学研究的热点之一.但长期以来,研究者更多地关注单一生态系统功能,而忽略了生态系统能够同时提供多种生态系统功能的能力,即生态系统多功能性(ecosystem multifunctionality,EMF).本文综述了EMF研究中功能指标的选择、生物多样性的不同维度、微生物多样性对EMF的影响以及其他非生物因子对EMF的驱动等进展.因只考虑单一功能可能会低估生物多样性对整体生态系统功能的影响,故生物多样性与生态系统多功能性(BEMF)关系的研究成为BEF关系研究的重点.近年来,BEMF关系的研究发展较快,在不同生态系统(包括水生、草地、森林、旱地、农业等)、不同研究尺度(从区域到全球尺度)、BEMF关系的驱动机制(从单一驱动机制到多种驱动机制共同作用)、研究方法(包括新概念以及新的量化方法的提出和应用)等方面均取得了新的进展.但仍有不足之处,如对于EMF研究中功能指标的选取没有统一的标准、对地下微生物多样性的关注度不够、涉及多营养级水平下的BEMF关系研究较少、驱动EMF的机制仍存在争论等.未来应加强对于功能指标选取的标准研究,综合分析地上、地下生物多样性以及非生物因子对EMF的整体影响,加强生态系统多服务性(ecosystem multiserviceability,EMS)方法的研究和应用.

Forests can provide multiple ecosystem functions simultaneously that are related to biomass production, soil carbon stock, and nutrient cycling, and plant diversity is often important for the maintenance of ecosystem multifunctionality (EMF). However, the underlying mechanisms involved in regulating relationships between species richness and abundance and EMF in a subtropical coniferous forest still remain unclear. Using a randomization test and structural equation model, we show that multiple plant diversity attributes, stand structural complexity, dominant species, and soil conditions affect EMF from 94 plots in Pinus kesiya dominant stands in southwest China. Our results indicate that the direct effects of species richness on EMF were stronger than the effects of woody individual abundance, and species richness increased with increasing EMF. By contrast, EMF declined with increasing total woody species abundance, while functional diversity and dominant species abundance did not exhibit significant effects on EMF. However, Castanopsis echidnocarpa abundance indirectly increased EMF via species richness and total woody species abundance. Simultaneously, our findings suggest that stand structural complexity mediated the relationship between plant diversity and EMF, and species richness, total woody species abundance, and EMF increased strongly with increasing stand structural complexity. Higher soil pH and soil water content were associated with greater stand structural complexity and EMF, which were important drivers in explaining variation in EMF. Our results show that higher species richness promoted EMF provisioning, and provide critical insights to predicting the possible consequences of EMF with a change in biotic and abiotic factors.

附生植物是森林生态系统中的重要结构性成分,对于维持森林生态系统物种多样性及生态系统功能均具有重要意义.该研究对云南普洱市太阳河省级自然保护区内季风常绿阔叶林5种微生境(陡坡、缓坡、高谷、沟谷和山脊)的附生维管植物组成进行野外实地调查,并结合地形数据和其他环境数据,分析了附生维管植物的多样性及其与微生境的关系.结果表明:(1)研究区季风常绿阔叶林中共记录附生维管植物97种12302株,分属16科45属;物种-多度曲线显示,隐柄尖嘴蕨(Belvisia henryi)、带状书带蕨(Vittaria doniana)、半圆盖阴石蕨(Humata platylepis)等3个物种优势明显.(2)山脊生境中附生维管植物具有更高的物种多样性和个体多度,而缓坡、沟谷生境中附生维管植物个体多度均较低.(3)在不同径级以及不同高度宿主之间的附生维管植物丰富度均具有显著差异(P<0.05),物种主要分布在中小径级宿主及林木树干中下部位.(4)影响附生维管植物物种丰富度、个体多度的主要环境变量为海拔高度、光照强度、温度;回归分析表明,附生维管植物物种丰富度与海拔高度呈线性正相关关系、与光照强度呈线性负相关关系;附生维管植物物种个体多度与光照强度呈线性负相关关系,与海拔高度和温度均呈线性正相关关系.

Soil microbial communities play an important role in maintaining the ecosystem during forest secondary succession. However, the underlying mechanisms that drive change in soil microbial community structures during secondary succession remain poorly defined in species-rich subtropical coniferous forests. In this study, Illumina high-throughput sequencing was used to analyze the variations in soil microbial community structures during forest secondary succession in subtropical coniferous forests in China. The role of soil properties and plant diversity in affecting soil bacterial and fungal communities was determined using random forest and structural equation models. Highly variable soil microbial diversity was observed in different stages of secondary succession. Bacterial community diversity rose from early to middle and late successional stages, whereas fungal community diversity increased from early to middle successional stages and then declined in the late stage. The relative abundance of Acidobacteria, Gemmatimonadetes, Eremiobacterota (WPS-2), Rokubacteria, and Mortierellomycota increased during succession, whereas the relative abundance of Ascomycota and Mucoromycota decreased. The community composition and diversity of the soil microbial community were remarkably influenced by plant diversity and soil properties. Notably, tree species richness (TSR) displayed a significant and direct correlation to the composition and diversity of both bacterial and fungal communities. The carbon-to-nitrogen (C:N) ratio had a direct impact on the bacterial community composition and diversity, and pH had a marked impact on the fungal community composition and diversity. Furthermore, succession stage and plant diversity indirectly impacted the composition and diversity of soil bacterial and fungal communities via soil properties. Overall, it can be concluded that soil intrinsic properties and plant diversity might jointly drive the changes in soil microbial community composition and diversity during secondary succession of subtropical coniferous forests.

AimsThe monsoon broad-leaved evergreen forest is a typical zonal vegetation of south subtropical China, where forest dynamics plot is a study platform of mechanisms of biodiversity maintenance and community assembly.Our objectives were to obtain plant association types in a 30 hm 2 forest dynamic monitoring plot in the Pu'er City, Yunnan Province. MethodsWe identified typical association types by the methods of multivariate regression trees, importance value, principal component analysis and indicator species based on 750 subplots (20 m × 20 m), and analyzed the differences of topography factors and community characteristics among different plant associations. Important findingsThe results showed that the specie richness of woody species (diameter at breast height (DBH) ≥ 1 cm) was 271, which belonged to 78 families and 178 genera in the forest dynamic plot.The community formation was Formation Castanopsis echidnocarpa.Forest was divided into four associations: (1) Lyonia ovalifolia + Aporosa villosa -Castanopsis echidnocarpa + Lithocarpus fenestratus Association, (2) Tapiscia yunnanensis + Lithocarpus grandifolius -Castanopsis echidnocarp + Schima wallichii Association, (3) Elaeocarpus