Components Of Functional Diversity Research Articles

Calculating functional diversity metrics using neighbor‐joining trees

The study of functional diversity (FD) provides ways to understand phenomena as complex as community assembly or the dynamics of biodiversity change under multiple pressures. Different frameworks are used to quantify FD, either based on dissimilarity matrices (e.g. Rao entropy, functional dendrograms) or multidimensional spaces (e.g. convex hulls, kernel‐density hypervolumes), each with their own strengths and limits. Frameworks based on dissimilarity matrices either do not enable the measurement of all components of FD (i.e. richness, divergence, and regularity), or result in the distortion of the functional space. Frameworks based on multidimensional spaces do not allow for comparisons with phylogenetic diversity (PD) measures and can be sensitive to outliers.We propose the use of neighbor‐joining trees (NJ) to represent and quantify FD in a way that combines the strengths of current frameworks without many of their weaknesses. Importantly, our approach is uniquely suited for studies that compare FD with PD, as both share the use of trees (NJ or others) and the same mathematical principles.We test the ability of this novel framework to represent the initial functional distances between species with minimal functional space distortion and sensitivity to outliers. The results using NJ are compared with conventional functional dendrograms, convex hulls, and kernel‐density hypervolumes using both simulated and empirical datasets.Using NJ, we demonstrate that it is possible to combine much of the flexibility provided by multidimensional spaces with the simplicity of tree‐based representations. Moreover, the method is directly comparable with taxonomic diversity (TD) and PD measures, and enables quantification of the richness, divergence and regularity of the functional space.

Differential response of the components of functional diversity in Orestias fishes (Cyprinodontidae) of the High Andean Plateau

Orestias (Cyprinodontiformes, Cyprinodontidae) is a diverse genus of freshwater fish endemic to the high Andean plateau (Altiplano) of the Andes Mountains, South America. Within the Altiplano, Orestias species form assemblages of varying taxonomic richness, exhibiting considerable diversity in morphological forms and sizes, and occupying different habitat types. Here, we investigate the functional diversity of Orestias assemblages in two basins within the Altiplano: Titicaca Lake and the southwestern Altiplano basins. Titicaca Lake is characterized by high species diversity that evolved sympatrically, while the southwestern Altiplano has lower species diversity that evolved allopatrically. Given that taxonomic diversity under sympatric conditions can promote greater functional diversity, we hypothesize that the Titicaca assemblage should display higher indicators of functional diversity. By using traits related to locomotion, food acquisition, and habitat type to quantify functional diversity we used four functional diversity indicators (functional richness, divergence, specialization, and originality) to compare the Orestias assemblages in two basins. We found no difference in functional divergence and originality between the Orestias from two basins. However, functional specialization was higher in the southwestern Altiplano, contrary to our hypothesis. Only functional richness was higher Titicaca assemblage; supporting our hypothesis. The differentiation between assemblages arises primarily from traits associated with locomotion and food acquisition. Several Orestias species are considered endangered and the extinction of any these taxa could impact the functional diversity of these basins.

Taxonomic richness and its relationship to the functional diversity of polychaetes in tropical estuaries

AbstractBiological diversity can be evaluated by the taxonomic and functional components. This study aimed to assess the relationship between taxonomic richness with the functional diversity components [functional richness (FRic), functional evenness (FEve) and functional divergence (FDiv)] and the functional trait dominance of polychaetes. In addition, we evaluated the environmental parameters that shape the functional structure in six tropical estuaries in north‐eastern Brazil. Three estuaries have a continuous environmental gradient (typical tropical), and the other three estuaries have no defined environmental gradient (semiarid tropical). We identified significant differences in the dominance of feeding strategy and habitat between estuaries, demonstrating that the functional space of the communities is not equally occupied. Also, the substrate particle size composition was correlated with the functional structure. FRic showed a positive relationship with taxonomic richness, regardless of the type of estuary. As taxonomic richness increases, the probability of different combinations of functional categories added to a community also increases. FEve and FDiv seem to be independent of taxonomic richness. Therefore, it is important to simultaneously evaluate diversity's taxonomic and functional components, considering the complementarity of the information provided by these diversity measures.

Bridging the Gaps: Exploring Aquatic–Terrestrial Connectivity through the Trait-Based Ecology of Riparian Predatory Arthropods

Riparian predatory arthropods represent one of the main trophic links between lotic and terrestrial ecosystems along riverine landscapes. The use of the trait-based approach promises to enhance our understanding of how these predatory communities interact with their environment through their response to various drivers of change and through their trophic interactions. We reviewed the scientific literature focused on the interaction between drivers of community change (natural and anthropogenic) and the functional traits and functional diversity components that characterize riparian ground beetles and spiders and, ultimately, on their role as cross-ecosystem trophic links. We highlight land use changes and river regulations as the strongest drivers that change the communities we study, often through various interacting mechanisms that favor the replacement of riparian specialists with generalist species, thus altering aquatic–terrestrial connectivity and the resilience of riverine arthropod consumers. Tropical regions and traits related to community responses to extreme climatic events (e.g., submersion tolerance and desiccation resistance) are less studied, while inconsistent patterns are noticed for well-studied traits, especially for spiders (e.g., their feeding preference response to aquatic subsidy availability and their body size response to flooding and bank hydrological connectivity). Future research should focus on the aforementioned drivers and knowledge gaps, along with the functional diversity changes in predatory arthropod communities along environmental and anthropogenic impact gradients, in order to improve riparian conservation.

Components of functional diversity revisited: A new classification and its theoretical and practical implications.

Functional diversity is regarded as a key concept for understanding the link between ecosystem function and biodiversity. The different and ecologically well-defined aspects of the concept are reflected by the so-called functional components, for example, functional richness and divergence. Many authors proposed that components be distinguished according to the multivariate technique on which they rely, but more recent studies suggest that several multivariate techniques, providing different functional representations (such as dendrograms and ordinations) of the community can in fact express the same functional component. Here, we review the relevant literature and find that (1) general ecological acceptance of the field is hampered by ambiguous terminology and (2) our understanding of the role of multivariate techniques in defining components is unclear. To address these issues, we provide new definitions for the three basic functional diversity components namely functional richness, functional divergence and functional regularity. In addition, we present a classification of presence-/absence-based approaches suitable for quantifying these components. We focus exclusively on the binary case for its relative simplicity. We find illogical, as well as logical but unused combinations of components and representations; and reveal that components can be quantified almost independently from the functional representation of the community. Finally, theoretical and practical implications of the new classification are discussed.

Functional trait composition of carabid beetle communities predicts prey suppression through both mass ratio and niche complementarity mechanisms.

Several components of predator functional diversity have been hypothesized to influence prey suppression through either niche complementarity or mass ratio effects. Nevertheless, most studies have used a functional group approach when assessing the role of these predators in ecosystem functioning. By adopting a trait-based approach, we evaluated the relative contributions of carabid diversity components in predicting prey suppression. Our results highlight the importance of both taxonomic and functional diversity components of carabids as key drivers of prey suppression. Prey suppression was best predicted by carabid densities, with the dominance of Poecilus cupreus potentially driving the positive effect of community total abundance through the mass ratio effect. Prey suppression increased with increasing the density of large carabids. In addition, carabid eye diameter and antennal length were key functional traits for predicting prey suppression. Furthermore, prey suppression increased with increasing carabid functional richness following the niche complementarity effect. In contrast to functional richness, functional evenness and functional divergence of carabid communities were weakly correlated with prey suppression. By identifying which diversity components of carabid communities contribute the most to increase prey suppression, our results can guide efforts aiming to predict the relationship between diversity of these predators and ecosystem functioning.

Taxonomical and functional analyses of epifaunal polychaetes associated with Mussismilia spp.: the effects of coral growth morphology.

The increasing habitat heterogeneity and complexity shows positive effects over different communities, leading to environmental diversity, access to resources and reducing the effectiveness of predation. In the present study we evaluate the structural and functional patterns of polychaete assemblages of three Mussismilia species with different coral morphology. Mussismilia hispida has a massive growth pattern; M. braziliensis also is a massive coral but forms a crevice in the corallum base; and M. harttii has a meandroid pattern. Ten individuals of the three Mussismilia species were sampled in two reefs in the Todos-os-Santos Bay, and we analyzed the differences in richness and abundance of polychaete species and the functional diversity metrics: Rao's quadratic entropy, functional dispersion, functional evenness, number of functional groups and functional richness, among Mussismilia species. Two-way ANOVA with permutations showed significant differences for polychaete abundances and richness among Mussismilia species (higher values for M. harttii), but no differences were recorded when compared between the two coral reef areas studied. There was no statistical difference among coral species or between reefs in relation to the functional diversity components influenced by abundance, such as Rao quadratic entropy, functional dispersion, and functional evenness. Some individual polychaete functional traits presented differences among Mussismilia species, and that also helped us to build a picture about the effect of different growth structures over functional aspects of polychaete assemblages. Thus, the taxonomical approach, the analysis of individual functional traits and the functional diversity metrics are fundamental tools to characterize the assemblage of organisms associated with corals.

Effects of surrounding landscape on the performance of Solidago canadensis L. and plant functional diversity on heavily invaded post-agricultural wastelands

High invasiveness and well-documented negative impact on biodiversity and ecosystem functioning make Solidago canadensis L. a species of global concern. Despite a good understanding of the driving factors of its invasions, it remains unclear how the surrounding landscape may shape invasion success of this species in human-transformed ecosystems. In our study, we investigated the impacts of different landscape features in the proximity of early successional wastelands on S. canadensis biomass allocation patterns. Further, we examined the relationships between the surrounding landscape, S. canadensis cover, and plant functional diversity, used as a supportive approach for the explanation of mechanisms underlying successful S. canadensis invasion. We found that increasing river net length had positive impacts on S. canadensis rhizome, stem, and total above ground biomass, but negative effects on leaf biomass, indicating that vegetative spread may perform the dominant role in shaping the competitiveness of this invader in riverine landscapes. A higher proportion of arable lands positively influenced S. canadensis above ground and flower biomass; thus promoting S. canadensis invasion in agricultural landscapes with the prominent role of habitat filtering in shaping vegetation structure. Concerning an increasing proportion of settlements, flower biomass was higher and leaf biomass was lower, thereby influencing S. canadensis reproductive potential, maximizing the odds for survival, and indicating high adaptability to exist in an urban landscape. We demonstrated high context-dependency of relationships between functional diversity components and surrounding landscape, strongly influenced by S. canadensis cover, while the effects of surrounding landscape composition per se were of lower importance. Investigating the relationships between the surrounding landscape, invasive species performance, and plant functional diversity, may constitute a powerful tool for the monitoring, controlling, and predicting of invasion progress, as well as the assessment of ecosystem invasibility.

The latitudinal gradient of functional diversity of Miocene marine mollusks from Chile

Understanding latitudinal variations in biodiversity is central for biogeography. Along the coasts of the Southeast Pacific, several taxa show inverse latitudinal patterns of biodiversity, i.e. increasing species numbers from lower to higher latitudes. A plausible explanation for these patterns is that fjords, formed during the Pleistocene glaciations, increased the diversity of available biotopes that allowed for higher diversity in high latitudes. Assessing this hypothesis requires us to analyze latitudinal patterns of functional diversity (which is intimately related to niche use) in the absence of fjords, i.e. earlier than their formation. Here we test if the fossil record before the generation of fjords shows higher functional diversity at lower than at higher latitudes (a ‘regular' functional diversity gradient).We analyzed four components of functional diversity (functional richness, functional divergence, functional dispersion and functional evenness) for a fossil marine mollusk fauna from the lower Miocene (~18 million years ago) across four regions spanning more than 10 latitudinal degrees of the Chilean coast (between ~34°S and 45°S).The functional richness of gastropods and bivalves decreased non‐linearly from low to high latitudes. Contrarily, the functional evenness of gastropods remained relatively constant across the region and that of bivalves peaked at 45°S. The functional divergence and functional dispersion of taxonomic groups did not exhibit clear patterns of latitudinal variation. The multivariate analysis uncovered non‐linear latitudinal patterns in the abundance of functional groups (gastropods and bivalves), with the largest abundance towards lower latitudes.These results suggest that the niche breadth of mollusk assemblages might have decreased with latitude in the lower Miocene. This work can shed light on the mechanisms underlying the latitudinal variation of diversity observed today, offering a better understanding of how these patterns changed over time.

Water management infrastructure alters plant species composition, functional diversity and soil condition in a livestock‐impaired mosaic of wetlands

AbstractAimsWetlands are key ecosystems due to their economic, social and environmental contributions. Because of their highly productive habitats and their dependence on hydro‐meteorologic regimes, they are threatened worldwide by land use and climate change. In most wetlands, intensification of productive activities has been mostly accompanied by the implementation of a water management infrastructure, disrupting water and nutrient dynamics. Our aim was to analyze whether intensification of livestock raising erodes the structure and function of plant communities, as well as the quality and fertility of soils in wetlands.LocationNon‐insular portion of the Lower Delta of the Paraná River, Argentina.MethodsPlant communities were characterized on the basis of their floristic composition, structural and functional diversity. Soil samples were also collected to assess soil fertility, texture and quality. Generalized mixed linear models were used to contrast these attributes across livestock management practices characterized by differing water management infrastructure (polders and channelizations) and livestock type (bovine, bubaline).ResultsRemarkably fertile hydromorphic soils supported a structurally rich and functionally diverse species composition. Nevertheless, most dominant populations were terrestrial, perennial, invasive species, partially adapted to conditions of temporary flooding. Polderized livestock fields exhibited not only the lowest quality, least fertile, most compacted soils, but also lower species richness and diversity, as well as the lowest values in all non‐redundant components of functional diversity. Channelized livestock fields exhibited lower species richness and taxonomic diversity as well as reduced soil quality and fertility, yet an overall increase in most non‐redundant components of functional diversity.ConclusionsPromoting the loss of native flora, water management infrastructure impairs the sustainability of anthropic activities and thwarts biodiversity conservation efforts. Traditional and sustainable practices that embrace the periodicity of the flood pulse are required to preserve the taxonomic and functional diversity of plant communities, as well as the quality and fertility of soils.

Functional diversity and species diversity in flooded and unflooded tropical forests

Functional diversity and species diversity provide information to understand differences between plant communities from a contrasting environment and the complementary on regional scale. Environmental variation determines which plants can persist in the community via species sorting processes; forest exposed to extended inundation each year has shown divergence in plant community composition, structure, and functional diversity, compared with unflooded dense forest. Here, we researched flooded and unflooded forests in the upper Magdalena River Valley (Colombia) to quantify and compare the plant species diversity and plant functional diversity. We calculated three components of functional diversity (i.e., functional richness, functional evenness, and functional divergence), we also used a measure of functional richness weighted by species abundance. Our results show that the plant community in the unflooded forest has higher stem density and lower basal area than flooded forests. Also, we show that tree communities in the flooded forests had higher specific leaf area, but lower wood density, suggesting an acquisitive resource strategy. Species diversity and functional diversity were higher in the plant community from the unflooded forest. Our findings of the functional traits and the functional diversity components reinforce the idea that the variation between flooded and unflooded forests is going beyond the species list in the plant communities. However, it is still unclear whether any general patterns exist regarding differences between flooded and unflooded tropical forests.

荒漠植物性状权衡策略及功能多样性研究进展

PDF HTML阅读 XML下载 导出引用 引用提醒 荒漠植物性状权衡策略及功能多样性研究进展 DOI: 10.5846/stxb202107151909 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（41961007）；甘肃省重点研发计划项目（21YF5FA082） Research progress on the trade-off strategy and functional diversity of desert plants 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:荒漠植物是干旱区具有独特功能性状与资源权衡表征的地带性植物。植物功能性状及其多样性格局与资源权衡策略对群落结构优化和生态系统功能改善起着关键作用。该综述主要从荒漠植物组织、器官功能性状特征、功能性状权衡策略、功能多样性组分及测度3个方面梳理了荒漠植物性状权衡策略与功能多样性研究的进展脉络：1）荒漠植物独特的根、茎、叶功能性状特征揭露了植被对环境变化的响应以及对生态系统功能的影响，基于植物功能性状的研究有助于解决许多生态学的关键性问题；2）作为植物功能性状之间存在的最普遍的联系，权衡策略是经过自然筛选后形成的性状组合，关键性状已经被发掘并创造性的提出了"经济谱"概念。荒漠植物研究过程中，应分析其根、茎、叶的特征属性筛选关键性状，着眼于关键性状间及整株植物性状间的权衡策略；3）功能多样性是影响生态系统运行和发挥作用的生物多样性的重要组成部分，荒漠植物功能多样性能预测和指示群落中物种对于荒漠生态系统功能发挥和过程变化的影响。功能多样性的组分可以从不同角度反映群落的生态位占据状况和资源利用程度，指数的选择要体现在群落内部物种的功能特征之间的差异程度，同时要考虑这些物种自身在群落内的优势程度。本研究为未来荒漠植物功能性状及多样性研究梳理了一些新的研究方向和内容，期望为荒漠植物生理生态学研究的选题和发展提供一些新的思路。 Abstract:Desert plants are zonal plants with unique functional traits and resource balance in arid areas. Plant functional traits and their diversity patterns and resource balancing strategies play a key role in the optimization of community structure and the improvement of ecosystem functions. This review summarized the research progress on functional diversity and trade-off strategies from three aspects:the functional traits of desert plant tissues and organs, the trade-off strategy of functional traits, components and measures of functional diversity. 1) The unique root, stem, and leaf functional traits of desert plants reveal the response of vegetation to the environmental changes and the impact on ecosystem functions. Research based on plant functional traits can help solve many key ecological problems; 2) As the most common relationship between plant functional traits, the trade-off relationship is a combination of traits formed after natural screening. Key traits have been discovered and the concept of "economic spectrum" has been creatively proposed. In the process of desert plant research, the characteristic attributes of desert plant roots, stems and leaves should be analyzed to screen key traits, focusing on the trade-off relationship between key traits and the whole plant traits; 3) The functional diversity is an important part of biodiversity that affects the operation and function of ecosystems. The functional diversity of desert plants can predict and indicate the impact of species in the community on the functioning and process changes of desert ecosystems. The components of functional diversity can reflect the niche occupancy status and resource utilization degree of the community from different angles. The choice of index should be reflected in the degree of difference between the functional characteristics of the species within the community, and at the same time, the species themselves should be considered the degree of dominance within the community. Finally, this article combs some new research directions and contents for future research on the functional traits and diversity of desert plants, and hopes to provide some new ideas for the topic selection and development of desert plant physiology and ecology. 参考文献 相似文献 引证文献

Exotic species elicit decoupled responses in functional diversity components of freshwater fish assemblages in Chile

In the freshwater basins of central Chile, 28 exotic species have been introduced, which have contributed to increase taxonomic diversity. Nevertheless, how these species have modified the components of functional diversity in these assemblages, a key aspect in learning about their present and future stability within an ecosystem, is unknown. In this study, we analyzed how the introduction of exotic species affects the functional diversity components of richness (FRic), divergence (FDiv), specialization (FSpe), and functional originality (FOri). Additionally, we simulated the effect of the loss (extinction/extirpation) of threatened native species. To do so, we gathered information on the distribution and functional characters of native and exotic species. Through Principal Coordinates Analysis (PCo), we obtained three independent axes (PCoA1, PCoA2, and PCoA3), which allowed us to define a multidimensional space and then to calculate FRic, FDiv, FSpe, and FOri. Our results indicate that richness and functional originality have increased significantly with the introduction of exotic species (263% and 32%, respectively). In contrast, functional divergence and specialization have remained the same. The possible extinction of threatened native species may promote increases in functional originality, decreases in functional richness and divergence, and unchanged functional specialization. On the other hand, a subset of exotic species presents novel features, while another shows redundant features with native ichthyofauna. We emphasize that the possible extinction of native species currently classified as threatened may lead to the disappearance of unique functional groups, which puts at risk the persistence and stability of these assemblages.

Critical areas for retaining multiple dimensions of bird diversity in the Cerrado

The taxonomic, phylogenetic, and functional components of diversity in communities show different spatial patterns that respond to climate and land-use change and are geographically convergent, i.e., areas with high species richness usually hold very different evolutionary lineages. The opposite – known as biotic homogenization – can also occur, which means that some sites end up concentrating closely related lineages or species that perform very similar roles in the system. Here, we assessed current relationships among the taxonomic, phylogenetic, and functional diversity components. We also analyzed how expected climate and land-use changes may alter such patterns in bird communities inhabiting the Cerrado. For this, we assessed the species range exposure to climatic variables and land use between the current period and 2050. We considered that the species would no longer occur in sites in their range where the climatic conditions in 2050 would exceed the limits currently tolerated and simultaneously lose native vegetation. In general, we found a high spatial incongruency among the three diversity components. We found that the higher the number of species in a site, the higher the number of different lineages it shelters. However, sites containing many species do not necessarily have more functional traits. We also found that due to climate changes and land use, only a small set of areas is expected to lose several bird species, while most Cerrado will lose few. Because of such expected species loss, bird communities might become more clustered in the future – both phylogenetically and functionally – and only a few areas will simultaneously safeguard this group's phylogenetic and functional diversity components.

Functional diversity response to geographic and experimental precipitation gradients varies with plant community type

Abstract Precipitation is a primary determinant of plant community structure in drylands. However, the empirical evidence and predictions are lacking for how plant functional diversity in desert and steppe communities respond to altered precipitation regimes. We examined how precipitation changes along the natural and experimental gradients affect different components of functional diversity in desert‐shrub and steppe‐grass communities. We compared the associations of precipitation changes with community‐weighted means (CWMs) of six traits, functional divergence (FDvar) of each single‐trait and multi‐trait functional richness (FRic) and dispersion (FDis) for shrub and grass communities along the natural and experimental gradients. We also disentangle the roles of species turnover and intraspecific variations in affecting the responses of different functional diversity to precipitation changes. We found that in general, the similar responses of functional traits or diversity to both the natural and experimental precipitation gradients were dependent on plant community type. Across both two gradients, precipitation was positively associated with CWM of plant height and negatively associated with the CWM of SLA and leaf thickness in grass community, while positively associated with FDvar of four traits and FDis in shrub communities. Both species turnover and intraspecific variations contributed to the responses of grass community traits to precipitation changes across both two gradients, and to FDvar of traits and FDis in shrub community along the natural gradient. In contrast, species turnover variations contributed to FDvar of traits and FDis in shrub community in experiment. These results suggest that there is better concordance between the effects of naturally and experimentally increased precipitation on functional diversity of plant communities, but different mechanisms behind the relationship of functional diversity–precipitation between shrub and grass communities. Grass communities can adapt to precipitation changes by average trait differences, while shrub communities persist through FDvar of single‐trait and multi‐trait dispersion, thus highlighting the important differences in adaptive strategies between shrub and grass communities. Our findings demonstrate that short‐term responses of plant communities to manipulative precipitation changes can reflect long‐term shifts at spatial scales depending on the specific functional trait and diversity. A free Plain Language Summary can be found within the Supporting Information of this article.

The effect of community‐wide phytochemical diversity on herbivory reverses from low to high elevation

Abstract Theory predicts that a large fraction of phytochemical diversity—the richness of individual chemical compounds produced by plants—governs the complexity of interactions between plants and their herbivores. While the effect of specific classes of chemical compounds on plant resistance against herbivores has been largely documented, the effect of community‐level variation in phytochemical diversity on plant–herbivore interactions has so far received minimal consideration. We hypothesized that plant communities bearing on average higher levels of phytochemical diversity should sustain lower herbivory rates, overall. Yet, the magnitude of this effect could vary across different environmental conditions, potentially because of climate‐mediated effects on phytochemical production and changes in herbivore community richness and composition. To address these hypotheses, we used previous knowledge of species‐level phytochemical make‐up for more than 400 plant species of the Swiss Alps. Using common garden experiments, we estimated season‐wide herbivore damage on low (average 3,500 unique molecules) and high (average 4,500 unique molecules) phytochemical diversity plant communities that were planted in the colline, mountain and alpine vegetation sites along two elevation transects in the Alps. We found that high phytochemical diversity plant communities showed reduced levels of herbivore damage in the colline (low elevation) sites, but this pattern reversed in the alpine (high elevation) sites. Our results suggest that the outcome of phytochemical diversity on plant–herbivore interactions depends on the characteristics of the local herbivore communities, together with trade‐offs between chemical defences and other plant traits (i.e. physical defences and plant palatability). Synthesis. Phytochemical diversity is a key component of functional diversity, influencing community composition and dynamics. We show that the effect of phytochemical diversity on herbivory is environmental‐dependent, generating ecological switches when moving from low to high elevation. Through upward movement of plants under climate change, phytochemical community structure will be likely modified, ultimately disrupting local community assembly processes.

Species and functional diversity — A better understanding of the impact of urbanization on bee communities

We examined site patterns in bee species for diversity and functional diversity in urban, suburban and rural areas. We sampled bees from all three habitat types and compiled a database of functional traits for each species.While species diversity decreased with urbanization, as expected, components of functional diversity showed differences between urban and suburban habitats. Functional dispersion (FDis) increased significantly in suburban areas as compared to urban sites, while functional divergence (FDiv) and functional redundancy (Fred) were higher in urban areas. Functional richness (FRic) and evenness (FEven) were not affected by urbanization. Moreover, assemblages in highly urbanized environments have a substantially different functional composition. Solitary species, cleptoparasites, soil nesters, bees with trophic specialization, and those with a short flight period turned out to be more sensitive to urbanization changes. This study highlights the importance of examining functional diversity in assessing human-induced biodiversity loss and its impacts on ecosystem functioning in urbanized areas.These results have significant implications for improving our understanding of the mechanisms of suburban community ecology and conserving bees in urban habitats.

Niche differentiation, competition or habitat filtering? Mechanisms explaining co‐occurrence of plant species on wet meadows of high conservation value

AbstractQuestionsDue to the diverse abiotic conditions and the extensive, early‐autumn, manual mowing practiced once per few years, Molinia semi‐natural wet meadows are known for their high plant species diversity. However, recent socio‐economic transformations and land‐use changes (i.e. cessation of use) have been contributing to significant biodiversity loss in Molinia meadows. Thus, understanding the mechanisms of species co‐occurrence patterns operating on well‐developed Molinia meadows may be a precondition for the restoration or regeneration success of this type of vegetation. We aimed to identify community‐level co‐existence patterns of the whole set of plant species typical of Molinia meadows, and to assess the role of co‐occurring vegetation in shaping the performance of individual species.LocationNatura 2000 Special Area of Conservation “Łąki Dąbrowskie” (S Poland).MethodsUsing generalised multiple regression techniques on a set of vegetation traits and components of functional diversity, we assessed the role of different ecological mechanisms in shaping co‐occurrence patterns of the entire group of species typical of Molinia meadows, as well as individual species belonging to this group.ResultsWhen the entire group of Molinia meadow species was taken into account, niche differentiation emerged as the main mechanism influencing the co‐occurrence of plant species. When considering individual species, we revealed that their co‐existence patterns were mostly species‐specific, pointing out the predominant role of either niche differentiation, competition, habitat filtering, or a combination of these three drivers in shaping assembly processes.ConclusionsOur results showed that the variability of niches realised by target species typical of Molinia meadows was high. Therefore, conservation of well‐developed Molinia meadows should focus on both the community, and on a single species level, aiming to maintain a complex of specific microhabitat conditions. Considering small‐size patches of these meadows scattered in a transformed, agricultural landscape, conservation of individual target species should be of the highest priority.

Phytoplankton Diversity Effect on Ecosystem Functioning in a Coastal Upwelling System

Species composition plays a key role in ecosystem functioning. Theoretical, experimental and field studies show positive effects of biodiversity on ecosystem processes. However, this link can differ between taxonomic and functional diversity components and also across trophic levels. These relationships have been hardly studied in planktonic communities of coastal upwelling systems. Using a 28-year time series of phytoplankton and zooplankton assemblages, we examined the effects of phytoplankton diversity on resource use efficiency (RUE, ratio of biomass to limiting resource) at the two trophic levels in the Galician upwelling system (NW Iberian peninsula). By fitting generalized least square models, we show that phytoplankton diversity was the best predictor for RUE across planktonic trophic levels. This link varied depending on the biodiversity component considered: while the effect of phytoplankton richness on RUE was positive for phytoplankton RUE and negative for zooplankton RUE, phytoplankton evenness effect was negative for phytoplankton RUE and positive for zooplankton RUE. Overall, taxonomic diversity had higher explanatory power than functional diversity, and variability in phytoplankton and zooplankton RUE decreased with increasing phytoplankton taxonomic diversity. Phytoplankton used resources more efficiently in warmer waters and at greater upwelling intensity, although these effects were not as strong as those for biodiversity. These results suggest that phytoplankton species numbers in highly dynamic upwelling systems are important for maintaining the planktonic biomass production leading us to hypothesize the relevance of complementarity effects. However, we further postulate that a selection effect may operate also because assemblages with low evenness were dominated by diatoms with specific functional traits increasing their ability to exploit resources more efficiently.

Functional erosion and trait loss in fish assemblages from Neotropical reservoirs: The man beyond the environment

AbstractAnthropogenic impacts are altering ecosystems, especially aquatic habitats, resulting in the loss of critical biodiversity. This study aimed to evaluate the influence of human pressure, as surrogated by the human footprint index (HFI), on the functional diversity of fish assemblages from 109 Neotropical reservoirs while considering covariates such as temperature, flooded area and age since damming. We assessed two components of functional diversity (richness and dispersion) and the specific trait composition of each fish assemblage. We found that both components of fish functional diversity decreased with increasing human pressure and that this relationship was stronger in reservoirs near large cities. There was a positive relationship between functional diversity and reservoir area, and a negative relationship between functional diversity and reservoir age. We also observed strong relationships between all the explanatory variables and functional traits, particularly for the HFI. We can infer that the ichthyofaunas of those reservoirs under higher human pressure are likely undergoing a simplification process along with homogenization of functional diversity.