ABSTRACT Predicting species distributions under future environmental change is essential for understanding biodiversity responses and informing conservation planning. Vaccinium, a genus that includes important germplasm resources for many commercial berry crops, comprises diverse berry wild relatives (BWRs) in China, yet research on their responses to environmental changes remains limited. Here, we used occurrences of eight Vaccinium BWRs in China and ensemble species distribution models to predict their distributions in the 2070s under climate and land‐use changes (SSP126, SSP245, and SSP585) together with two dispersal scenarios (20 km/decade and full dispersal). We found stronger effects from climate‐related variables than land‐use variables on the distributions of the eight BWRs. The current potential distribution areas were largely consistent with known distributions, with generally high or moderate suitability. Most species would have their range size contracted, while two species were projected to have considerable range size increased. There was a trend of range shifts toward higher latitudes for most species. Based on projected persistent suitable areas, three northeastern distributed species would have their habitat limited in the Greater Khingan Mountains area, while five southern distributed species would harbor relative stability in their own specific areas. These findings enhance our understanding of how climate and land‐use changes may reshape the distributions of Vaccinium BWRs in China and provide valuable insights for their long‐term conservation and management.

The nitrogen (N) vs. phosphorus (P) scaling exponent, indicating the allocation strategies of the two nutrients, plays an important role in predicting plant and ecosystem functioning. Besides the constant scaling relationship of N vs. P, plasticity of scaling exponents has been demonstrated, with proposed potential causes including plant functional groups (PFGs) or environmental factors. However, relatively little is known about whether the N vs. P scaling exponent of different PFGs response similarly to different environmental conditions. We measured N and P concentrations in leaves and twigs of 964 shrub individuals in a secondary subtropical forest in Eastern China and explored how the N vs. P scaling exponent vary with different light or soil nutrient conditions for deciduous and evergreen shrubs. The leaf N vs. P scaling exponent of evergreen but not deciduous shrubs was affected by light condition, with higher scaling exponent of understory shrubs than that of typical shrubs. The twig scaling exponent of understory shrubs was lower than that of typical shrubs for both PFGs. With increasing soil N availability, responses of scaling exponents in both organs for both PFGs consistent with compliant type first and resistant type later. The scaling exponents of deciduous and evergreen shrubs in both organs showed opposite trends at a relatively high soil P availability level. Our results reveal that environmental factors may alter the N vs. P scaling exponent differently across PFGs. These findings have important implications for improving predictions of stoichiometric models and broadening our understanding of plant responses to varying environments. This study investigates the N vs. P scaling exponents of leaves and twigs in deciduous and evergreen shrubs under different light or soil nutrient conditions in a secondary subtropical forest, revealing that environmental factors may alter the scaling exponents differently across plant functional groups. The study provides new insights for improving stoichiometric model predictions and deepening our understanding of plant responses to environmental variability. (sic)(sic):(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic), (sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)964(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic):1)(sic)(sic)(sic)(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).2)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).3)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).

Predicting changes in suitable areas under climate and land use changes, and identifying persistent suitable areas for economically valuable plant species, are critical for future conservation and cultivation. Camellia chekiangoleosa, Camellia drupifera, Camellia oleifera and Camellia reticulata serve as important woody oilseed species in China, providing both economic and ecological benefits. Here, we predict the distributions of the four species under climate and land use changes (SSP126, SSP245 and SSP585 in 2070) combining two dispersal constraint scenarios (full dispersal and 20 km/decade) by using ensemble species distribution models. The results showed that the current potential suitable areas of the four species coincided with their current known distribution regions; most of these areas are of high suitability. Among the environmental variables, climatic factors have stronger effects on the distribution of the four species than land use factors. In response to climate and land use changes, the range sizes of C. chekiangoleosa and C. drupifera were projected to increase, while for C. oleifera and C. reticulata the range would contract. In addition, the centroid of the suitable range would shift in different directions and distances for different species. As a result of distinctive range shifts, the studied species have their own specific areas of persistent suitability in southern China. Notably, except for the widespread C. oleifera, there is almost no overlap in the persistent suitable areas among the other three species. This study gives us a better understanding of the impact of climate and land use changes on the major Camellia oilseed species in China, thus guiding the selection of sites for oil tea plantations and the conservation of germplasm resources.

地下芽植物能够通过地下储存器官占据生境资源、储存营养物质等策略来获得生态优势，其地下储存器官多样性以及生物量分配策略，对地下芽植物物种组成以及生态系统功能产生重要影响。然而，以往研究多关注草地生态系统的地下芽植物，对森林地下芽植物的了解仍然缺乏。采集了古田山国家级自然保护区不同海拔分布的693个草本植物个体，分析了地下芽植物及其地下储存器官的类型与多样性，比较了地下芽植物与非地下芽植物的地上、地下各器官的绝对、相对生物量。结果显示：（1）地下芽植物的相对丰富度为69.1%,相对多度为88.2%。大多为根状茎植物，主要由禾本科、莎草科、堇菜科和蕨类植物组成。（2）除茎外，地下芽植物各器官的绝对生物量（叶：1.94g,根：0.65g,地上部分：2.0g,地下部分：4.1g）均大于非地下芽植物（叶：0.26g,根：0.13g,地上部分：0.68g,地下部分：0.13g）。（3）地下芽植物叶（0.40）与茎（0.14）的相对生物量小于非地下芽植物（叶：0.48,茎：0.35）,地下部分相对生物量（0.56）大于非地下芽植物（0.17）。本研究表明，以根状茎植物为主的地下芽植物是古田山亚热带森林生态系统草本植物的主要构成者，且个体普遍较大，倾向于将生物量投资于地下器官。这些结果为认识地下芽植物的生态策略与功能以及草本植物群落管理提供了科学依据。

Biomass allocation strategies among geophytes and non-geophytes generally determine the ecological adaptation and impacts of herbaceous plants. Although geophytes and non-geophytes are key components of the biodiversity of subtropical forest ecosystems, strategies for biomass allocation of both remain unknown. In this study, 695 individual herbaceous plants were collected from low, middle, and high altitude regions in Qianjiangyuan National Park. We analyzed the biomass and allometric trajectories of the leaves, stems, roots, and underground storage organs of whole herbs, geophytes, and non-geophytes. The results showed that: (1) The overall allometric trajectory of understory herbs changed with increase in altitude. Allocation was reduced to stems and leaves and increased to roots. (2) In geophytes, the allocation was reduced to leaves and stems and increased to underground storage organs and roots, which follows the optimal partitioning theory. In the biomass trade-off of the aboveground parts, the stem is preferred. (3) However, the allometric trajectories of non-geophytes are less susceptible to changes in the altitude, and the biomass allocation strategy depends only on plant size which follows allometric partitioning theory. In the biomass trade-off of the aboveground parts, the leaves are preferred. Totally, geophytes and non-geophytes adopted different biomass allocation strategies as adaptations to altitudinal changes in the environment. The plant functional type is the major determinant of biomass allocation in herb species. This study has implications for the management practices of herbaceous plants and predicting changes in understory vegetation.

铝毒是限制酸性土壤中作物产量的主要因素之一.番茄(Solanum lycopersicum)是适合在酸性土壤中种植的主要经济作物,不同品种番茄对铝胁迫的响应存在差异,因此,筛选苗期耐铝毒种质对番茄生产及研究具有重要意义.以10个番茄品种为材料,采用室内土培盆栽,设置1 000 μmol·L-1AlCl3·6H2O处理,测定反映植物铝胁迫下生长状况的16个形态、生理生化及光合指标.通过主成分分析,将铝胁迫下番茄幼苗的16个指标转化为5个独立的综合指标,累积贡献率达90.779％.基于耐铝性综合评价值(A)的系统聚类分析,将供试种质划分为5类,第Ⅰ类为高度耐铝品种Qianxi,第V类为高度不耐铝品种Puluowangsi.经多元线性逐步回归分析得出番茄苗期耐铝评价方程:y=0.046+0.405X6+0.515X10-0.207X15+0.028X3(R2=0.997),从16个指标中提取出与A值显著相关(P＜0.01)的4个指标:丙二醛含量(X3)、净光合速率(X6)、叶面积(X10)和地下部干重(X15).利用评价方程可判断不同番茄品种苗期的耐铝性,使番茄耐铝性鉴定工作快速简便.

为综合开发利用油茶资源,以茶籽饼为供试材料,探究微波辅助法提取茶皂素的最佳条件,并利用黑曲霉对残余茶皂素进一步降解,探明地衣芽孢杆菌发酵脱皂茶粕为生物饲料的最优方案.在70℃、600 W下,以茶粕:70％乙醇为1∶ 12的料液比微波提取l h得到的茶皂素得率最高,可达9.20％.在时间12 d、温度37.5℃、pH 6.5、接种质量分数12％条件下黑曲霉降解效果最佳.在3.6 d、34℃、pH 7.1、接种质量分数5％的条件下地衣芽孢杆菌发酵饲料的可消化性蛋白和糖含量最高.研究结果表明采用黑曲霉高效降解茶皂素并通过地衣芽孢杆菌发酵茶粕为高品质饲料,对提高油茶籽的综合利用率、缓解茶粕堆放造成的环境压力具有重要意义.

通过土培法探究化感作用下栝楼的生理响应及根际相关指标的动态变化.以抗性品种安徽潜山栝楼和敏感性品种浙江温州栝楼为实验材料,用不同时间段提取的根系分泌物和茎叶浸出液进行实验处理,测定了2个品种栝楼抗氧化酶活性、丙二醛含量及吲哚乙酸氧化酶活性等相关指标.结果表明:经胁迫后,2个品种栝楼幼苗的SOD,POD,CAT活性均降低,同时能明显诱导MDA含量的积累,变化幅度与提取时间及处理周期成正相关;栝楼胚轴吲哚乙酸氧化酶(IAAO)活性总体上与根系分泌物、茎叶浸出液的提取时间成正相关,只有短时间提取(≤24 h)的茎叶浸出液使其活性下降23.81％～58.49％;长时间提取(>24 h)的根系分泌物在胁迫时间≥8 d时,可明显抑制根系活力,增大细胞质膜透性,其中温州栝楼根系活力降幅达33.03％和38.51％,而潜山栝楼在茎叶浸出液下表现为低促高抑;在化感物质的胁迫下,细菌的数量呈现上升趋势,放线菌的数量出现下降情况,但总体上升.总之,抗性品种可缓解化感作用,潜山栝楼与温州栝楼相比表现出较强抗性,这为农作物种植过程中栽培最优品种、保证产量提供了理论依据.

树皮是木本植物茎干最外层结构,具有保护茎干、养分储存与运输等重要作用。因此,树皮厚度是一项非常重要的功能性状,其变异不仅影响树皮的各种生态功能,还能影响群落构建与物种共存。然而,以往对树皮厚度的研究集中于火灾易发生态系统,对火灾不易发生的亚热带常绿阔叶林的研究仍较缺乏。测量了古田山国家级自然保护区亚热带常绿阔叶林内树种的树皮厚度,并检验了总树皮厚度、内树皮厚度与外树皮厚度在各分类群间以及功能群间的差异。结果发现:1) 39个树种807个个体的总树皮厚度、内树皮厚度与外树皮厚度均值分别为1.90 mm、1.38 mm和0.54 mm。漆树科（Anacardiaceae）、杨梅科（Myricaceae）以及亚热带常绿阔叶林代表类群壳斗科（Fagaceae）、山茶科（Theaceae）的树皮厚度较大。短柄枹（Quercus serrata）、木荷（Schima superba）、小叶青冈（Cyclobalanopsis myrsinifolia）等树种的树皮厚度较大。2)种间、科间的各树皮厚度差异均显著。不同功能类群间,乔木类群的各树皮厚度均较灌木类群大,常绿类群的各树皮厚度均较落叶类群大（内树皮厚度除外）。本次研究结果表明,相对于火灾易发生态系统中的树皮厚度,古田山亚热带常绿阔叶林群落内的树皮厚度相对较薄,表明这些森林树种对当地湿润气候的适应性。同时,树皮厚度在各种分类水平与功能群水平间的显著变异,反映了群落内不同生态策略的共存。

Ecosystem restoration is regarded as one of the most cost-effective ways of mitigating the effects of the ongoing climate- and anthropogenic changes and slow or revert the loss of biodiversity. Forest restoration has much potential to conserve forest specialist species and ecosystem services, by using multiple, native tree species to promote a high local diversity of trees, with likely positive effects on overall biodiversity and on ecosystem resilience. In this study, we assessed the potential of using two rare, native species of the yew family (Taxaceae) in forest restoration in China. Species of this family are only rarely used in reforestation despite their potential contribution to tree functional diversity as long-lived, shade-tolerant, evergreen understory trees with fleshy seed cones of value to frugivorous animals. By using species distribution modelling methods, we analysed national and local scale occurrence data for Taxus cuspidata and Torreya grandis to determine the climate-based potential ranges as well as important factors for growth on a local scale. The analyses showed that both species have large potential ranges driven mainly by precipitation and by comparing these ranges with the areas that have potential for sustaining forests, we found large areas available for forest restoration where these species could be included. On the local scale, we found that low light levels and low competition from co-occurring trees are more important for the growth of seedlings compared to the adult individuals of both species. If the ecological requirements for seedlings are ensured, i.e. by creating moderately shaded environments in which seedlings can escape competition, both Taxaceae species have high potential for reforestation in China and will increase the ecological qualities of a restored forest, and at the same time, the conservation of rare tree-species in their native ranges is ensured. Conclusively, both Ta. cuspidata and To. grandis are shade-tolerant, slow-growing trees that, by creating an evergreen scrubby layer, add to forest structural complexity and stability, thereby helping support ecosystem services and biodiversity, e.g. microhabitat and resources for birds and other animals.

Aims Multi-stemming supports plants'resilience to disturbances and then contributes to soil stabilization and forest function,especially in mountain habitats.Many questions remain about(i)the ontogenetic phase at which multiple stems can occur,(ii)how habitat drivers affect multi-stemming and(iii)whether ontogenetic phase and habitat drivers interact.We asked these questions for Quercus glauca(ring-cupped oak),the dominant species and sprouter across large warm-temperate areas of Asia;its multi-stemmed trees reflect individual survival,population regeneration and forest ecosystem stability.Methods In a 5-ha permanent plot of subtropical evergreen broad-leaved forest in eastern China,we examined the temporal patterns and spatial distribution of multi-stemmed trees of Q.glauca within 99 quadrats of 20 m x 20 m.Important Findings There were three temporal modes for multi-stemming among the Q.glauca trees and most of them appeared to produce multiple stems from an early stage.Environmental disturbances related to slope convexity appear to be the main drivers of multi-stemming of Q.glauca.Moreover,the closer to the ridge,the earlier the multi-stemming occurs.Thus,also for other woody species in other forests and climate zones,ontogeny and environmental drivers promoting disturbance(not only geomorphology,but also extreme weather events,soil drought,fire),as well as soil fertility,need to be considered in combination to better understand multi-stemming and its consequences for community structure.

Subtropical forest is recognized as an important global vegetation type with high levels of plant species richness. However, the mechanisms underlying its diversity remain poorly understood. Here, we assessed the roles of environmental drivers and evolutionary dynamics (time-for-speciation and diversification rate) in shaping species richness patterns across China for a major subtropical plant group, the tea family (Theaceae s.s.) (145 species), at several taxonomic scales. To this end, we assessed the relationships between species richness, key environmental variables (minimum temperature of the coldest month, mean annual precipitation, soil pH), and phylogenetic assemblage structure (net related index) by using non-spatial and spatial linear models. We found that species richness is significantly related to environmental variables, especially soil pH, which is negatively related to species richness both across the whole family and within the major tribe Theeae (116 species). Family-level species richness is unrelated to phylogenetic structure, whereas species richness in tribe Theeae was related to phylogenetic structure with U-shaped relationship, a more complex relation than predicted by the time-for-speciation or diversification rate hypotheses. Overall, these results suggest that both environmental and evolutionary factors play important roles in shaping species richness patterns within this subtropical plant family across China, with the latter mainly important at fine taxonomic scales. Most surprisingly, our findings show that soils can play a key role in shaping macro-scale diversity patterns, contrary to often-stated assumptions.

Theaceae is a plant family that mainly distributed in tropical or subtropical regions of Asia. Most species of Theaceae are endemic to China. Here, we used the herbarium collections aim to: a) detect the spatial species richness patterns; b) find out the geographical divisions and c) detect the environmental drivers of the dissimilarity patterns (β diversity). The current distributions of 193 Theaceae species were modeled using MaxEnt. Meanwhile, we calculated the pair wise dissimilarity between grid cell assemblages based on beta-sim index. An ordination was used to analyze the environmental drivers of the dissimilarity patterns. We found that the diversity hotspots for Theaceae species mainly locate in Fujian and Guangxi province. Two major divisions were suggested by the ordination analysis. The longitudinal division implies the climatic divergences between southeastern and southwestern China, while the latitudinal division implies the geographical barriers. For the species in southeastern China, the dissimilarity pattern is mainly driven by temperature annual range, annual precipitation and annual mean temperature. In the southwestern China, isothermality, precipitation seasonality and the rising altitude are the three main drivers. For effective conserving the Theaceae species, the protection of the micro-habitats and the high diversity areas on both sides of these divisions will be essential.

Deterministic and stochastic processes jointly determine the community dynamics of forest succession. However, it has been widely held in previous studies that deterministic processes dominate forest succession. Furthermore, inference of mechanisms for community assembly may be misleading if based on a single axis of diversity alone. In this study, we evaluated the relative roles of deterministic and stochastic processes along a disturbance gradient by integrating species, functional, and phylogenetic beta diversity in a subtropical forest chronosequence in Southeastern China. We found a general pattern of increasing species turnover, but little-to-no change in phylogenetic and functional turnover over succession at two spatial scales. Meanwhile, the phylogenetic and functional beta diversity were not significantly different from random expectation. This result suggested a dominance of stochastic assembly, contrary to the general expectation that deterministic processes dominate forest succession. On the other hand, we found significant interactions of environment and disturbance and limited evidence for significant deviations of phylogenetic or functional turnover from random expectations for different size classes. This result provided weak evidence of deterministic processes over succession. Stochastic assembly of forest succession suggests that post-disturbance restoration may be largely unpredictable and difficult to control in subtropical forests.

Negative density dependence and habitat filtering are important mechanisms to explain the coexistence of species and the biodiversity patterns of forest communities. Negative density dependence is assumed to enhance phylogenetic α diversity via negative interactions among individuals within a species or among closely related species via competition for similar resources and the sharing of similar pathogens and predators. In contrast, habitat filtering is hypothesized to reduce phylogenetic β diversity within a habitat by selecting for similar resident species that can tolerate the habitat and by eliminating other species. Previous studies focused mainly on testing these two hypotheses by analyzing the spatial patterns of species diversity. Only a handful of studies have examined the temporal variation in phylogenetic community structure. This study attempted to test these two mechanisms by analyzing the temporal variation in community phylogenetic diversity of seedlings (DBH<1 cm) in 342 quadrats (1 m×1 m) in a mid-subtropical forest in Gutianshan National Nature Reserve, Zhejiang Province, China. We found that the phylogenetic α diversity of seedling within habitats increased significantly from the year 2006 to 2007. In contrast, the phylogenetic β diversity of seedlings within habitats declined significantly over time. These results suggested that negative density dependence and habitat filtering jointly determined the phylogenetic diversity patterns of communities in this subtropical forest.

Phylobetadiversity can provide new insights into assembly mechanisms of community ecology because it incorporates phylogenetic information. The combination of phylobetadiversity and traditional species beta diversity is of great benefit to research that attempts to explain the mechanisms of community assemblages. To reveal the community assembly mechanisms of a 24-hm2 forest plot established in Gutianshan National Nature Reserve, Kaihua County, Zhejiang, China, our study used four spatial statistical models to simulate model communities created in four ways: purely random processes, environmental filtering, dispersal limitations and the combination of environmental filtering and dispersal limitation. Then we analyzed the distance-decay of similarity of these four model communities and observed communities based on the plot in the Gutianshan National Nature Reserve. Our results showed (1) an obvious distance-decay relationship exists for species and phylogenetic similarity in the Gutianshan plot; (2) the combined effects of environmental filtering and dispersal limitation can best explain the mechanisms involved in structuring species beta diversity in the plot; and (3) different results were produced using pairwise ( D pw) and nearest neighbor ( D nn) metrics. The results from the nearest neighbor metric ( D nn) suggested that the combined effects of environmental filtering and dispersal limitation shape the community phylogenetic structure of the plot. Additionally, the results from the pairwise metric ( D pw) showed that the combined effect of environmental filtering and dispersal limitation can best explain the community phylogenetic structure at the scales of 20 m2×20 m2, while environmental filtering is the main force shaping community phylogenetic structure at scales of 40 m2×40 m2 and 50 m2×50 m2. The combined patterns observed when considering both phylobetadiversity and traditional species beta diversity reflected the important roles of habitat filtering and dispersal limitation in diversity maintenance of this subtropical forest habitat.

The phylogenetic conservatism of plant functional traits and its association with community structure are important topics in ecological research. Plant functional traits are simultaneously affected by their evolutionary background,local habitat conditions and large-scale climate. In this study we asked whether functional traits have a significant phylogenetic signal and significantly affect species abundance in a community. For this objective,we used data from a 24 ha Gutianshan forest plot,which included species abundance and six functional traits of 156 woody species: leaf nitrogen content,leaf phosphorus content,leaf area,wood density,specific leaf area and seed mass. We found that all functional traits showed significant phylogenetic signal,suggesting that all functional traits are significantly affected by their evolutionary history. We also found that species abundance was correlated with leaf nitrogen content,leaf phosphorus content,leaf area,woody density and specific leaf area except seed mass,suggesting that resource acquisition significantly affects species abundance distribution in a community,and that these functional traits impact community structure in different ways.

Forests across the world are increasingly affected by human activities, with unmanaged forests often in early- and mid-successional phases after anthropogenic disturbances. In consequence, it is important to obtain a better understanding of these successional dynamics and their implications for the functioning of forest ecosystems. Here, we investigate this issue for a highly diverse subtropical forest in China, as it is particularly relevant here. China naturally harbors large forested areas and much forest biodiversity, but its forests are also subject to strong anthropogenic pressures, with only 2% of its forest remaining undisturbed. We assess how anthropogenic disturbance shapes two important aspects of forest biodiversity, namely phylogenetic and functional community structure. Comparing plots that have not been disturbed within the last 100 years, plots clear-cut similar to 50 years ago, and plots clear-cut similar to 50 years ago and then selectively cut similar to 20 years ago, we find that the abundant gymnosperm species which are important pioneer species in southern China strongly affect phylogenetic structure, causing over-dispersion among large stems in disturbed stands. A tendency for decreasingly clumped phylogenetic structure over succession when considering only angiosperms may reflect an initial filtering by disturbance whose legacy decreases during succession. Multi-trait functional structure, which was not significantly affected by gymnosperms, has similar patterns to the phylogenetic structure without gymnosperms. Phylogenetic and functional structure differs among stem size classes, but with partially divergent trends. Functional structure is more strongly linked to a disturbance indicator, the proportion of light-demanding species, than phylogenetic structure. Our results illustrate that past tree harvesting has left strong legacies in the phylogenetic and functional structure of tree stands in a highly diverse southern Chinese forest and thus may also shape their functioning. (C) 2013 Elsevier B.V. All rights reserved.

Phylobetadiversity incorporates phylogenetic information and beta diversity, and can account for the ecological similarities between communities with a phylogenetic perspective. Although different phylobetadiversity indices reflect differences in different characteristics between communities, the results of different phylobetadiversity indices are not comparable. In this study we examined phylobetadiversity indices for a 24-hm2 plot in the Gutianshan National Nature Reserve. It was found the abundance-weighted D pw was almost identical to Rao’s D of Rao’s quadratic entropy. PhyloSor had a similar ecological meaning and algorithm to UniFrac. Although D nn was different in definition from UniFrac and PhyloSor, they were all strongly correlated. The effect of species abundance on phylobetadiversity was not significant when scales were relatively small, but was significant at larger scales. These contrasts likely resulted from reductions in evenness in communities as scales increased. P ST and Rao’s H better reflected the distance-decay changes caused by spatial and habitat variation than other indices at larger scales, whereas AW-D nn and D nn better reflected these changes at small scales.

Two different Al genotype of buckwheat named Jiangxi buckwheat(Al-tolerance) and Neimeng buckwheat(Al-sensitive) were selected as material in this paper.The responses of leaf area,chlorophyll content and chlorophyll fluorescence to phosphorus(P) and aluminum(Al) were characterized in comparison between these two Al genotypes.Results indicated that the leaf area,Chl a,Chl T contents,maximum fluorescence(Fm) and electronic transfer rate(ETR) decreased under 200 μmol.L-1 Al treatment in both two genotypes.The minimal fluorescence(Fo) increased significantly and PSⅡmaximum fluorescence efficiency(Fv / Fm) decreasing in Neimeng buckwheat,but there was no distinct variety of Fo and Fv / Fm in Jiangxi buckwheat.Compared with 200 μmol.L-1 Al treatment solely,Chl a and Chl T contents increased significantly,value of Fv/Fm increased slightly and Fo decreased in both two buckwheats when treated with P and Al alternatively.Fm and ETR increased at different level of P and Al treatments in Neimeng and Jiangxi buckwheat.All these results suggested that phosphorus could ameliorate the inhibition to arose,prevent damnification to photosynthesis organ caused by Al toxicity and benefit photosynthesis for plants.