Functional richness, functional evenness and functional divergence: the primary components of functional diversity

Abstract Functional diversity (FD) approaches have been increasingly used to understand ecosystem functioning in bird communities. These approaches typically rely on the assumption that species are perfectly detected in the field, despite the fact that imperfect detection represents a ubiquitous source of bias in biodiversity studies. This may be notably important in FD studies, because detection may depend on the functional traits used to compute FD metrics. However, little effort has been devoted to account for imperfect detection in FD studies, and therefore the degree to which species traits and detectability affects FD remains poorly understood. We predict that observed FD metrics may either underestimate or overestimate detection-corrected FD, because FD has multiple independent dimensions with different data properties. We assessed whether detection was related to bird traits (body mass, diet, and foraging stratum), accounting for habitat type, season, and phylogeny. We then used a multi-species occupancy model to obtain detection-corrected FD metrics (functional richness [FRic], functional evenness [FEve], and functional divergence [FDiv]), and compared observed and detection-corrected FD estimates in bird communities from east-central Argentina. Some functional types of birds (raptors and insectivores) were more easily overlooked, whereas others (seed and leaf eaters) were more easily detected. Some observed FD metrics underestimated detection-corrected FD (FRic and FDiv), whereas some others (FEve) overestimated detection-corrected FD. Both observed and detection-corrected FRic revealed differences between seasons, but not between habitat types. However, detection-corrected FEve and FDiv showed differences between seasons, contrary to observed estimates. Our results indicate that failure to account for unequal ease of detecting species can lead to erroneous estimates of FD because some functional types of birds are more easily overlooked. We outline some guidelines to help ornithologists identifying under which circumstances detection may be a concern and warn against the indiscriminate use of FD metrics without accounting for species detection.

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Global change in the functional diversity of marine fisheries exploitation over the past 65 years

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.0889 ◽

2020 ◽

Vol 287 (1933) ◽

pp. 20200889 ◽

Cited By ~ 1

Author(s):

Isaac Trindade-Santos ◽

Faye Moyes ◽

Anne E. Magurran

Keyword(s):

Functional Diversity ◽

Functional Divergence ◽

Marine Ecosystem ◽

Temporal Trends ◽

Functional Trait ◽

Marine Fisheries ◽

Large Marine Ecosystems ◽

The Past ◽

Functional Richness ◽

Spatial And Temporal Trends

Overexploitation is recognized as one of the main threats to global biodiversity. Here, we report a widespread change in the functional diversity of fisheries catches from the large marine ecosystems (LMEs) of the world over the past 65 years (1950 to 2014). The spatial and temporal trends of functional diversity exploited from the LMEs were calculated using global reconstructed marine fisheries catch data provided by the Sea Around Us initiative (including subsistence, artisanal, recreational, industrial fisheries, and discards) and functional trait data available in FishBase. Our analyses uncovered a substantial increase in the functional richness of both ray-finned fishes (80% of LMEs) and cartilaginous species (sharks and rays) (75% of LMESs), in line with an increase in the taxonomic richness, extracted from these ecosystems. The functional evenness and functional divergence of these catches have also altered substantially over the time span of this study, with considerable geographic variation in the patterns detected. These trends show that global fisheries are increasingly targeting species that play diverse roles within the marine ecosystem and underline the importance of incorporating functional diversity in ecosystem management.

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Influences of the area, shape and connectivity of coastal lakes on the taxonomic and functional diversity of fish communities in Southern Brazil

Zoologia (Curitiba) ◽

10.3897/zoologia.36.e23539 ◽

2019 ◽

Vol 36 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Sandra Maria Hartz ◽

Elise Amador Rocha ◽

Fernanda Thiesen Brum ◽

André Luís Luza ◽

Taís de Fátima Ramos Guimarães ◽

...

Keyword(s):

Functional Diversity ◽

Fish Communities ◽

Taxonomic Diversity ◽

Analytical Framework ◽

Freshwater Species ◽

Coastal Lakes ◽

Causal Connections ◽

Functional Richness ◽

Dispersal Abilities ◽

Functional Evenness

In this study we investigated the influence of landscape variables on the alpha taxonomic and functional diversity of fish communities in coastal lakes. We built an analytical framework that included possible causal connections among variables, which we analyzed using path analysis. We obtained landscape metrics for the area, shape and connectivity (estuary connectivity and primary connectivity to neighboring lakes) of 37 coastal lakes in the Tramandaí River Basin. We collected fish data from 49 species using standardized sampling with gillnets and obtained a set of traits related to dispersal abilities and food acquisition. The model that best explained the taxonomic diversity and functional richness took into account the shape of the lakes. Functional richness was also explained by estuary connectivity. Functional evenness and dispersion were not predicted by area or connectivity, but they were influenced by the abundant freshwater species. This indicates that all lakes support most of the regional functional diversity. The results highlight the importance of the dispersal process in this lake system and allow the conclusion that considering multiple diversity dimensions can aid the conservation of local and regional fish communities.

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Linking functional diversity to ecological indicators: A tool to predict the anthropogenic effects on ecosystem functioning

Environmental Reviews ◽

10.1139/er-2021-0093 ◽

2022 ◽

Author(s):

Leticia Bonilla-Valencia ◽

Silvia Castillo-Argüero ◽

José Alejandro Zavala-Hurtado ◽

Francisco Javier Espinosa-García ◽

Roberto Lindig-Cisneros ◽

...

Keyword(s):

Functional Diversity ◽

Plant Traits ◽

Functional Divergence ◽

Seed Mass ◽

Ecosystem Processes ◽

Ecological Indicators ◽

Ecological Indicator ◽

Dry Matter Content ◽

Weed Species ◽

Functional Richness

Functional diversity is related to the maintenance of processes and functions in ecosystems. However, there is a lack of a conceptual framework that highlights the application of functional diversity as an ecological indicator. Therefore, we present a new initiative for motivating the development of ecological indicators based on functional diversity. We are interested in showing the challenges and solutions associated with these indicators. We integrated species assemblage theories and literature reviews. We considered plant traits related to ecosystem processes and functions (specific leaf area, leaf dry matter content, wood density, phenology, and seed mass) to show the application of a selection of functional diversity metrics that can be used as ecological indicators (i.e., Community Weighted-Mean, Functional Divergence, Functional Richness and Functional Evenness). We caution that functional diversity as an ecological indicator can be misinterpreted if species composition is unknown. Functional diversity values can be overrepresented by weed species (species established in disturbed sites) and do not maintain original processes and functions in ecosystems. Therefore, we searched for evidence to demonstrate that weed species are ecological indicators of functional diversity changes. We found support for two hypotheses that explain the effect of weed species on ecosystem function: functional homogenization and functional transformation. Likewise, we showed the application of some tools that can help study the anthropogenic effect on functional indicators. This review shows that the paradigm of addressing the effects of disturbances on ecosystem processes by using functional diversity as an ecological indicator can improve environmental evaluation, particularly in areas affected by human activities.

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Temporal heterogeneity affects the process of succession but not its direction in abandoned croplands in a semi-arid area of northwest China

10.5194/egusphere-egu2020-12288 ◽

2020 ◽

Author(s):

Fujiang Hou ◽

An Hu ◽

Shenghua Chang ◽

Xianjiang Chen

Keyword(s):

Functional Diversity ◽

Aboveground Biomass ◽

Functional Divergence ◽

Wiener Index ◽

Northwest China ◽

Temporal Heterogeneity ◽

Slow Increase ◽

Artemisia Capillaris ◽

Semi Arid ◽

Functional Evenness

Spatial heterogeneity has been widely used in the study of succession in abandoned croplands worldwide, and it is often accompanied by time heterogeneity. However, the effect of temporal heterogeneity on succession dynamics over decades is not well understood. Here, we used croplands with same history in northwest China that were abandoned in 1998, 1999, and 2000 and continuously monitored vegetation characteristics for ten years. Croplands were left undisturbed throughout the study. Non-metric multidimensional scaling was used to interpret changes in the plant community, and taxonomic and functional diversity measures were compared in three treatment over time. Our results show that the directions of succession in all three croplands were similar, from single superior community (Salsolacollina Pall.) with higher aboveground biomass to multi-superior community (Artemisia capillaris Thunb., Stipa bungeana Trin., Lespedeza davurica (Laxm.) Schindl, Heteropappus altaicus (Willd.) Novopokr) with lower aboveground biomass. Taxonomic and functional diversity increased rapidly in the first 4&#8211;6 years, followed by a slow increase, decrease or stabilization. Temporal heterogeneity had no effect on species richness after the 7th year, on the Shannon-Wiener index, species evenness, modified functional attribute diversity, or functional divergence after the 8th year, or functional evenness after 5th year. We conclude that temporal heterogeneity can affect the process of secondary succession but has no effect on the direction of community succession. Our findings provide evidence for using temporal heterogeneity to study succession in abandoned croplands in semi-arid areas.&#160;

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Community-weighted mean traits but not functional diversity determine the changes in soil properties during wetland drying on the Tibetan Plateau

Solid Earth ◽

10.5194/se-8-137-2017 ◽

2017 ◽

Vol 8 (1) ◽

pp. 137-147 ◽

Cited By ~ 7

Author(s):

Wei Li ◽

Howard E. Epstein ◽

Zhongming Wen ◽

Jie Zhao ◽

Jingwei Jin ◽

...

Keyword(s):

Tibetan Plateau ◽

Soil Properties ◽

Leaf Area ◽

Functional Diversity ◽

Functional Divergence ◽

The Tibetan Plateau ◽

Dry Matter Content ◽

Weighted Mean ◽

Functional Richness ◽

Community Weighted Mean

Abstract. Climate change and human activities have caused a shift in vegetation composition and soil biogeochemical cycles of alpine wetlands on the Tibetan Plateau. The primary goal of this study was to test for associations between community-weighted mean (CWM) traits, functional diversity, and soil properties during wetland drying. We collected soil samples and investigated the aboveground vegetation in swamp, swamp meadow, and typical meadow environments. Four CWM trait values (specific leaf area is SLA, leaf dry matter content is LDMC, leaf area is LA, and mature plant height is MPH) for 42 common species were measured across the three habitats; three components of functional diversity (functional richness, functional evenness, and functional divergence) were also quantified at these sites. Our results showed that the drying of the wetland dramatically altered plant community and soil properties. There was a significant correlation between CWM of traits and soil properties, but not a significant correlation between functional diversity and soil properties. Our results further showed that CWM-LA, CWM-SLA, and CWM-LDMC had positive correlations with soil readily available nutrients (available nitrogen, AN; available phosphorus, AP), but negative correlations with total soil nutrients (soil organic carbon is SOC, total nitrogen is TN, and total phosphorus is TP). Our study demonstrated that simple, quantitative plant functional traits, but not functional diversity, are directly related to soil C and N properties, and they likely play an important role in plant–soil interactions. Our results also suggest that functional identity of species may be more important than functional diversity in influencing ecosystem processes during wetland drying.

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Functional, size and taxonomic diversity of fish along a depth gradient in the deep sea

PeerJ ◽

10.7717/peerj.2387 ◽

2016 ◽

Vol 4 ◽

pp. e2387 ◽

Cited By ~ 13

Author(s):

Beth L. Mindel ◽

Francis C. Neat ◽

Clive N. Trueman ◽

Thomas J. Webb ◽

Julia L. Blanchard

Keyword(s):

Species Richness ◽

Continental Slope ◽

Functional Diversity ◽

Deep Sea ◽

Morphological Traits ◽

Fish Assemblages ◽

Functional Divergence ◽

Feeding Guilds ◽

Functional Richness ◽

Size Diversity

Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300–2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf.

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Bird Functional Diversity in Agroecosystems and Secondary Forests of the Tropical Andes

Diversity ◽

10.3390/d13100493 ◽

2021 ◽

Vol 13 (10) ◽

pp. 493

Author(s):

Vanessa Velásquez-Trujillo ◽

Juan F. Betancurt-Grisales ◽

Angela M. Vargas-Daza ◽

Carlos E. Lara ◽

Fredy A. Rivera-Páez ◽

...

Keyword(s):

Functional Diversity ◽

Functional Divergence ◽

Tail Length ◽

Diversity Indices ◽

Secondary Forests ◽

Tropical Andes ◽

Behavioral Traits ◽

Functional Richness ◽

Wing Chord ◽

Functional Diversity Indices

Agricultural systems have increased in extension and intensity worldwide, altering vertebrate functional diversity, ecosystem functioning, and ecosystemic services. However, the effects of open monoculture crops on bird functional diversity remain little explored, particularly in highly biodiverse regions such as the tropical Andes. We aim to assess the functional diversity differences of bird guilds between monoculture crops (coffee, cocoa, and citrus) and secondary forests. We use four functional diversity indices (Rao Q, Functional Richness, Functional Evenness, and Functional Divergence) related to relevant morphological, life history, and behavioral traits. We find significant differences in functional diversity between agroecosystem and forest habitats. Particularly, bird functional diversity is quite homogeneous among crop types. Functional traits related to locomotion (body weight, wing-chord length, and tail length), nest type (closed), and foraging strata (canopy and understory) are dominant at the agroecosystems. The bird assemblages found at the agroecosystems are more homogeneous in terms of functional diversity than those found at the secondary forests, as a result of crop structure and management. We recommend promoting more diverse agroecosystems to enhance bird functional diversity and reduce their effects on biodiversity.

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Common latitudinal gradients in functional richness and functional evenness across marine and terrestrial systems

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.0745 ◽

2019 ◽

Vol 286 (1908) ◽

pp. 20190745 ◽

Cited By ~ 4

Author(s):

M. Schumm ◽

S. M. Edie ◽

K. S. Collins ◽

V. Gómez-Bahamón ◽

K. Supriya ◽

...

Keyword(s):

Species Richness ◽

Functional Groups ◽

Functional Diversity ◽

Skewed Distribution ◽

Model Systems ◽

Latitudinal Gradients ◽

Ecological Specialization ◽

Functional Richness ◽

The Tropics ◽

Functional Evenness

Functional diversity is an important aspect of biodiversity, but its relationship to species diversity in time and space is poorly understood. Here we compare spatial patterns of functional and taxonomic diversity across marine and terrestrial systems to identify commonalities in their respective ecological and evolutionary drivers. We placed species-level ecological traits into comparable multi-dimensional frameworks for two model systems, marine bivalves and terrestrial birds, and used global species-occurrence data to examine the distribution of functional diversity with latitude and longitude. In both systems, tropical faunas show high total functional richness (FR) but low functional evenness (FE) (i.e. the tropics contain a highly skewed distribution of species among functional groups). Functional groups that persist toward the poles become more uniform in species richness, such that FR declines and FE rises with latitude in both systems. Temperate assemblages are more functionally even than tropical assemblages subsampled to temperate levels of species richness, suggesting that high species richness in the tropics reflects a high degree of ecological specialization within a few functional groups and/or factors that favour high recent speciation or reduced extinction rates in those groups.

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Invasive legume affects species and functional composition of mountain meadow plant communities

Biological Invasions ◽

10.1007/s10530-020-02371-w ◽

2020 ◽

Author(s):

Wiebke Hansen ◽

Julia Wollny ◽

Annette Otte ◽

R. Lutz Eckstein ◽

Kristin Ludewig

Keyword(s):

Species Diversity ◽

Functional Diversity ◽

Plant Communities ◽

Functional Divergence ◽

Ecosystem Change ◽

Species Number ◽

Vegetation Types ◽

Lupinus Polyphyllus ◽

Mountain Meadow ◽

Functional Richness

Abstract Plant invasions are among the key drivers of global biodiversity and ecosystem change. They often cause reductions in native species richness and overall biodiversity. Nitrogen-fixing plants are problematic as they affect soil nutrient availability and outcompete species of nutrient-poor sites. Here we assessed the impacts of the legume Lupinus polyphyllus on species and functional diversity of mountain meadow communities in the UNESCO Biosphere Reserve Rhön. We compared species diversity (richness, evenness and effective species number), functional diversity (functional richness, evenness, divergence and dispersion) and similarity of plots in three characteristic vegetation types (Nardus grassland, mesic and wet mountain hay meadows) between different lupine cover classes. We calculated community weighted means (CWMs) of single plant traits and plotted them against lupine cover classes. The invasion of L. polyphyllus homogenizes vegetation composition since the similarity among plots of the different vegetation types increased with increasing lupine cover. It significantly affected species diversity in terms of richness and effective species number and the functional divergence of the vegetation. The trait set of species occurring together with lupine was shifted towards more competitive trait values. We demonstrate strongly negative impacts of L. polyphyllus on different mountain meadow vegetation types since L. polyphyllus, fosters the growth of competitive species and leads to overall more productive plant communities.

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