Disturbance effects on species diversity and functional diversity in riparian and upland plant communities

QuestionsTo what extent do changes in management (abandonment and fertilization) affect plant functional and taxonomic diversity in wet meadow communities? To what extent do the changes in functional and taxonomic diversity depend on site productivity?LocationŽelezné hory Mts., Czech Republic.MethodsExperimental plots were established on 21 wet meadows differing in productivity and species composition. In each meadow, in 2007, four 1 × 1 m plots were established, representing a full factorial design with abandonment and fertilization as the factors. In each plot, the number of species present was recorded in 100 subplots (0.1 × 0.1 m) in the years 2007, 2009 and 2011. Different indicators of functional diversity (functional richness, functional evenness, and Rao′s quadratic entropy) were calculated using five functional traits (SLA, LDMC, seed mass, plant height and clonality). Both abundance‐weighted and non‐weighted diversity indices were calculated. Randomization tests (conducted with PERMANOVA) were used to assess the effect of site productivity and management on both α‐ and β‐diversity components.ResultsMeadows along the productivity gradient differed in functional and taxonomic diversity. Both abandonment and fertilization decreased taxonomic diversity. Whereas fertilization decreased functional richness and Rao′s quadratic entropy, abandonment decreased functional evenness. The changes in both taxonomic and functional diversity caused by abandonment and fertilization occurred faster in more productive meadows.ConclusionsThe increased dominance of tall species with abandonment and fertilization, followed by the loss of species and the decrease in various indicators of functional diversity, suggest that increased competition for light resulted in increased trait convergence among co‐existing species. In addition, many processes occurring after abandonment and fertilization depend on meadow productivity. Results suggest that abundance‐ and non‐abundance‐weighted diversity indices give complementary insights on community structure. These results imply that changes are needed in current meadow management and conservation.

Although species richness has been hypothesized to be highest at 'intermediate' levels of disturbance, empirical studies have demonstrated that the disturbance-diversity relationship can be either negative or positive depending on productivity On the other hand, hypothesized productivity diversity relationships can be positive, negative or unimodal, as confirmed by empirical studies. However, it has remained unclear under what conditions each pattern is realized, and there is little agreement about the mechanisms that generate these diverse patterns. In this study, I present a model that synthesizes these separately developed hypotheses and shows that the interactive effects of disturbance and productivity on the competitive outcome of multispecies dynamics can result in these diverse relationships of species richness to disturbance and productivity The predicted productivity diversity relationship is unimodal but the productivity level that maximizes species richness increases with increasing disturbance. Similarly, the predicted disturbance diversity relationship is unimodal but the peak moves to higher disturbance levels with increasing productivity Further, these patterns are well explained by the opposite effects of productivity and disturbance on competitive outcome that are suggested by the change in community composition along these two environmental gradients: higher productivity favours superior competitors while higher disturbance levels favour inferior competitors.

Plant species diversity and functional diversity relations in the degradation process of desert steppe in an arid area of northwest China

The effect of woody encroachment on taxonomic and functional diversity and soil properties in Cerrado wetlands

Do species and functional trait diversity respond similarly to deterministic and random processes? Theory predicts that the contributions of random and deterministic processes to species diversity depend on patch size. Smaller patches are more strongly influenced by random sampling effects, by having fewer individuals, as well as ecological drift, which propagates the effects of small samples through stochastic birth and death processes. These random processes decrease species richness and increase compositional differences among small patches. Larger patches are predicted to be more deterministically assembled, with greater species richness and greater predictability of composition for a particular environment. The consequences of patch size for the diversity of functional traits, however, are poorly understood. Species diversity may be a poor proxy for functional diversity due to trait redundancies among species, making it unclear how random and deterministic processes alter functional diversity within patches of differing size, and how these differences scale up to determine among‐patch functional diversity. We report a novel experimental study of species and functional diversity across spatial scales. We manipulated patch area in an experimental plant metacommunity and used a nested sampling design to distinguish the effects of deterministic processes, ecological drift and sampling effects on species and functional trait diversity. Our study revealed a pervasive influence of ecological drift and sampling effects on diversity, with distinct influences on functional traits and species composition within and among patches. Overall, drift and sampling effects caused a two‐ to threefold decrease in the importance of deterministic processes in small fragments. Species and functional diversity showed similar patterns with patch size; larger patches had greater within‐patch (alpha) diversity and lower among‐patch (beta) diversity, consistent with theory. However, our nested sampling design revealed that sampling effects (i.e. the size of the sample area) largely determined alpha species diversity and beta functional diversity, while ecological drift had a stronger influence on alpha functional diversity and beta species diversity. Synthesis. The compositions of species and functional diversity in a community are influenced by distinct processes, resulting in divergent spatial scaling of species and their traits within patches and across landscapes.

PDF HTML阅读 XML下载 导出引用 引用提醒 天坑森林植物群落叶功能性状、物种多样性和功能多样性特征 DOI: 10.5846/stxb202110273025 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31960047）；珍稀濒危动植物生态与环境保护教育部重点实验室研究基金（ERESEP2019Z04）；广西重点研发计划项目（桂科AB21220057）；广西漓江流域景观资源保育与可持续利用重点实验室研究基金（LRCSU21Z0101） Leaf functional traits, species diversity and functional diversity of plant community in Tiankeng forests Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以天坑内部-边缘-外部森林植物群落为研究对象，通过调查植物的群落结构、叶功能性状，探究天坑内外森林植物群落叶功能性状、物种多样性和功能多样性变化特征及其内在关联，为深入了解负地形森林生态系统的功能和恢复退化喀斯特地区的植被提供一定参考。研究结果如下：（1）比叶面积（198.75 cm2/g））、叶面积（42.70 cm2）、叶磷含量（1.70 g/kg）和叶钾含量（10.27 g/kg）在天坑内部最高，叶组织密度（0.32 g/cm3）和叶干物质含量（0.41 g/g）在天坑外部最高，天坑内外森林均易受到磷限制，表明随天坑内部-边缘-外部生境变化，植物对环境的适应机制和生存策略发生了部分调整，物种的防御策略增强，生长投入策略减弱。（2） Shannon-Wiener指数（2.82）、Simpson指数（0.92）和Pielou's均匀度指数（0.87）均以天坑外部最高，功能丰富度（1.05）、功能离散度（1.88）和Rao's二次熵（4.52）以天坑内部最高，表明随天坑内部-边缘-外部生境的变化，植物功能性状的差异减少，物种分布及其功能性状分布总体上更为均匀、物种数量增多。（3）物种多样性指数之间、功能多样性指数之间存在较强的相关性，表明物种多样性指数之间、功能多样性指数之间存在不同的制约关系。（4）叶功能性状与物种多样性、功能多样性的相关性强，物种多样性和功能多样性之间相关性较弱，表明叶性状对生态学过程的变化较为敏感，叶功能性状与物种多样性之间存在较强的耦合关系。 Abstract:To explore leaf functional traits, species diversity, and functional diversity characteristics and correlation of plant community in Tiankeng forests will help to build the context of leaf traits, species diversity, and functional diversity research context, and further understand the process and functions of the ecological system in the negative terrain forest, and provide a scientific basis for restoration and reconstruction of the vegetation in degraded karst areas. This paper takes the woody plant community in three habitats (the inside of Tiankeng, the fringe of Tiankeng, and the outside of Tiankeng) of Dashiwei Tiankeng Group as the object, to study the leaf functional traits, species diversity, functional diversity characteristics and their interactions, through community investigation and leaf functional traits measurement. The results are as follows:(1) woody plant grown in the inside of Tiankeng shows the highest specific leaf area (SLA:198.75 cm2/g), leaf area (LA:42.70 cm2), leaf phosphorus content (LPC:1.70 g/kg) and leaf potassium content (LKC:10.27 g/kg), in the outer of Tiankeng presents the highest leaf tissue density (LTD:0.32 g/cm3) and leaf dry matter content (LDMC:0.41 g/g), and the growth of woody plant is limited by P in Tiankeng forests and nearby karst forests. With the variation of habitats from the inner to the outer of Tiankeng, partial adjustments are made in the adaption mechanism and survival strategy of the woody plant. A quick defense strategy on investment for the species increases, while a slow growth strategy on investment of species is weak. (2) Shannon-Wiener index (2.82), Simpson index (0.92) and Pielou's evenness index (0.87) in the outside of Tiankeng are the highest, and the functional richness index (1.05), function dispersion index (1.88) and Rao's quadratic entropy index (4.52) in the inside of Tiankeng are the highest. With the variation in the inner-edge-outer habitats of Tiankeng community, the differences in plant functional traits reduce, the range of species distribution and functional traits are steady, and the individual of species increases. (3) There is significantly correlated to each species diversity and functional diversity, indicating that there are different restrictive relationships between species diversity and functional diversity. (4) The leaf functional traits are significantly correlated with species diversity and functional diversity, and the correlation between species diversity and functional diversity is weak, indicating that leaf traits are more sensitive to variation of ecological processes and there is a strong coupling relationship between leaf functional traits and species diversity. 参考文献 相似文献 引证文献

Local biodiversity has traditionally been estimated with taxonomic diversity metrics such as species richness. Recently, the concept of biodiversity has been extended beyond species identity by ecological traits determining the functional role of a species in a community. This interspecific functional diversity typically responds more strongly to local environmental variation compared with taxonomic diversity, while taxonomic diversity may mirror more strongly dispersal processes compared with functional metrics. Several trait‐based indices have been developed to measure functional diversity for various organisms and habitat types, but studies of their applicability on aquatic microbial communities have been underrepresented. We examined the drivers and covariance of taxonomic and functional diversity among diatom rock pool communities on the Baltic Sea coast. We quantified three taxonomic (species richness, Shannon's diversity, and Pielou's evenness) and three functional (functional richness, evenness, and divergence) diversity indices and determined abiotic factors best explaining variation in these indices by generalized linear mixed models. The six diversity indices were highly collinear except functional evenness, which merely correlated significantly with taxonomic evenness. All diversity indices were always explained by water conductivity and temperature–sampling month interaction. Taxonomic diversity was further consistently explained by pool distance to the sea, and functional richness and divergence by pool location. The explained variance in regression models did not markedly differ between taxonomic and functional metrics. Our findings do not clearly support the superiority of neither set of diversity indices in explaining coastal microbial diversity, but rather highlight the general overlap among the indices. However, as individual metrics may be driven by different factors, the greatest advantage in assessing biodiversity is nevertheless probably achieved with a simultaneous application of the taxonomic and functional diversity metrics.

The effects of biodiversity on ecosystem functioning comprise a central ecological theorem (BEF), because more diverse communities are expected to perform better, for example, in terms of resource use efficiency (RUE). Although biodiversity affects ecosystem functioning, it is seriously constrained by global environmental change. Epilithic algae are a crucial benthic functional group in aquatic food webs, but the effect of their biodiversity on ecosystem functioning is yet to be understood. Here, we compared the capacity of taxonomic versus functional richness and evenness to predict RUE in a dataset on epilithic algae from the Qinhuai River, Nanjing, China. We examined associations between environmental variables and taxonomic and functional diversity (response and ecological indication), and assessed whether taxonomic and functional diversity measures predicted RUE (quantified as total algal biomass standardised by total phosphorus (RUETP), and total nitrogen (RUETN)). Taxonomic and functional diversity varied more across seasons than space, peaking in spring and summer in association with pronounced environmental changes. Water temperature and nutrient concentrations positively and significantly predicted taxonomic and functional diversity measures. Taxonomic and functional richness positively associated with RUE, while functional evenness negatively associated. However, taxonomic evenness was not related to RUE. Structural equation modelling showed that taxonomic and functional diversity were positively associated with RUETP and RUETN. However, taxonomic diversity was more strongly predictive of RUE than functional diversity. Our results suggest that RUE is closely linked to species diversity, and functional diversity provides a complementary approach for better understanding of mechanisms underlying the BEF relationship for benthic algae in large rivers. We suggest using taxonomic and functional approaches in a complementary way to gain a deeper understanding of the interplay among environmental factors, community diversity and ecosystem functioning.

Frameworks exclusively considering functional diversity are gaining popularity, as they complement and extend the information provided by taxonomic diversity metrics, particularly in response to disturbance. Taxonomic diversity should be included in functional diversity frameworks to uncover the functional mechanisms causing species loss following disturbance events. We present and test a predictive framework that considers temporal functional and taxonomic diversity responses along disturbance gradients. Our proposed framework allows us to test different multidimensional metrics of taxonomic diversity that can be directly compared to calculated multidimensional functional diversity metrics. It builds on existing functional diversity-disturbance frameworks both by using a gradient approach and by jointly considering taxonomic and functional diversity. We used previously unpublished stream insect community data collected prior to, and for the two years following, an extreme flood event that occurred in 2013. Using 14 northern Colorado mountain streams, we tested our framework and determined that taxonomic diversity metrics calculated using multidimensional methods resulted in concordance between taxonomic and functional diversity responses. By considering functional and taxonomic diversity together and using a gradient approach, we were able to identify some of the mechanisms driving species losses following this extreme disturbance event.

The expansion of agriculture is a major driver of biodiversity loss worldwide, through changes generated in the landscape. Despite this, very little is still known about the complex relationships between landscape composition and heterogeneity and plant taxonomical and functional diversity in Mediterranean ecosystems that have been extensively managed during millennia. Although according to the Intermediate Disturbance Hypothesis (IDH) plant richness might peak at intermediate disturbance levels, functional diversity might increase with landscape heterogeneity and decrease with the intensity of disturbance. Here, we evaluated the associations of landscape composition (percentage of crops) and heterogeneity (diversity of land-cover classes) with plant taxonomical diversity (richness, diversity, evenness), local contribution to beta diversity, and functional diversity (functional richness, evenness, divergence and dispersion) in 20 wild Olea europaea communities appearing within agricultural landscapes of Mallorca Island (Western Mediterranean Basin). In accordance with the IDH, we found that overall plant richness peaked at intermediate levels of crops in the landscape, whereas plant evenness showed the opposite pattern, because richness peak was mainly related to an increase in scarce ruderal species. Plant communities surrounded by very heterogeneous landscapes were those contributing the most to beta diversity and showing the highest functional richness and evenness, likely because diverse landscapes favour the colonization of new species and traits into the communities. In addition, landscape heterogeneity decreased functional divergence (i.e., increased trait overlap of dominant species) which may enhance community resilience against disturbances through a higher functional redundancy. However, a large extent of agriculture in the landscape might reduce such resilience, as this disturbance acted as an environmental filter that decreased functional dispersion (i.e, remaining species shared similar traits). Overall, our study highlights the importance of considering several indices of taxonomical and functional diversity to deeply understand the complex relationships between ecosystems functions and landscape context.

Environmental filtering and management effects on functional and taxonomic reef fish diversity in the Abrolhos Reefs, Brazil.

Windstorm effects on herbaceous vegetation in temperate forest ecosystems: Changes in plant functional diversity and species trait values along a disturbance severity gradient

Exploring taxonomic, functional, and structural diversity can provide additional insights into our understanding of diversity responses to environment. Using altitude, slope, and relative radiation index as well as floristic and functional data from a South Africa Afromontane forest, we examined how taxonomic, structural, and functional diversity varied with local environmental variation. Taxonomic and structural diversity were quantified through species richness- and diameter class-based Shannon index and evenness, respectively. Skewness and coefficient of variation of diameter distribution were additionally computed for structural diversity. As for functional diversity, we used functional richness, evenness, divergence, and dispersion based on functional traits. Data were analyzed using multimodel inference and subset regression. We found little evidence of environmental effects on local-scale taxonomic diversity patterns. In contrast, structural and functional diversity metrics varied significantly along environmental gradients. Accordingly, diameter class-based Shannon evenness declined with increasing slope while skewness and coefficient of variation of diameter distribution increased with increasing slope. Functional evenness and divergence decreased with increasing altitude and radiation, respectively, while functional richness and dispersion increased with increasing slope. The results showed that taxonomic diversity patterns were less responsive to local-scale topographical variation than structural and functional diversity. Lower functional diversity on lower slope sites suggests weak environmental filtering effect promoting competitive exclusion and dominance of species with acquisitive traits. On higher slope sites, environmental filtering associated with slope gradient seems to favor coexistence of species with conservative traits and adapted to harsh conditions.

The relationship between species diversity and functional diversity along aridity gradients in semi-arid rangeland

The relationship between species diversity and ecosystem function is one of the core problem of biodiversity research, and productivity is an important modality of ecosystem function. The species diversity of natural communities is often strongly related to their productivity. The grassland is an important component of terrestrial ecosystems and plays a significant role in the biodiversity and ecosystem function. Understanding of how to use natural vegetation to restore deteriorated grasslands is critical for protection of grassland ecosystems. Moreover, the relationship between species richness and productivity relies on scales. At some scales, productivity affects diversity, and at other scales, species diversity also affects productivity. Thus, it is necessary to know the relationship between plant functional diversity and productivity in different grassland types. In 2003 the differences in plant functional diversity, functional composition and productivity in different grassland types of alpine meadow were analyzed. Humans are modifying both the identities and the numbers of species in ecosystems. However, the impacts of such changes on ecosystem processes are still controversial. The effects of functional diversity and composition on plant community productivity were analyzed in four types of alpine meadows. The research results show:(1) the effects of the legume functional group on productivity was greater than other functional groups in Kobresia humlis meadow and Potentilla froticosa shrub. (2) Although the biomass of forbs, C 3 plants and sedge functional groups account for higher proportion of community productivity in Kobresia pygmaca meadow and K. tibetica swamp meadow, differences were not significantly different, indicating that the factors influencing community productivity were not only species diversity, but also the identity of species present and environmental resources. These factors were in turn mainly affected by species diversity and evenness among functional groups. That is, differences in functional group composition have a larger effect on ecosystem processes than functional group richness alone. (3) A significant correlation was found between the coverage per functional group and the primary productivity of communities in the four types of alpine meadows. (4) Changes in productivity with number of species per functional group showed a unimodal pattern, such that the maximum community productivity occured at an intermediate level of number of species per functional group.