On the challenge of treating various types of variables: application for improving the measurement of functional diversity

Pavoine, Sandrine; Vallet, Jeanne; Dufour, Anne‐Béatrice; Gachet, Sophie; Daniel, Hervé

doi:10.1111/j.1600-0706.2009.16668.x

Cited by 133 publications

(196 citation statements)

References 41 publications

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“…If d ij is calculated using the Gower distance (Pavoine et al 2009), the value of the Rao index obtained from the combination of a given set of traits is equal to the average of Q calculated for single traits. Here, Champely and Chessel (2002) noted that for any coefficient of the form 1 2 d 2 ij where d ij is a dissimilarity coefficient that is embeddable in Euclidean space (for details, see Gower and Legendre 1986), it is possible to derive a multivariate version of Eq.…”

Section: Discussionmentioning

confidence: 99%

“…It is easily shown that for d ij = 1 for all i = j, and d ii = 0 for all i, Q reduces to the well-known Gini-Simpson index. Some relevant mathematical properties of the Rao coefficient have been studied by a number of authors (Shimatani 2001;Szeidl 2006, 2009;Pavoine et al 2009), and the reader is addressed to their papers for details. From Eqs.…”

Section: Measuring Single-trait Diversitymentioning

confidence: 99%

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CWM and Rao’s quadratic diversity: a unified framework for functional ecology

2011

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Assessing the effects of environmental constraints on community structure often relies on methods that consider changes in species functional traits in response to environmental processes. Various indices have been proposed to measure relevant aspects of community trait composition from different viewpoints and perspectives. Among these, the 'community-weighted mean trait value' (CWM) and the Rao coefficient have been widely used in ecological research for summarizing different facets of functional composition and diversity. Analyzing changes in functional diversity of bee communities along a post-fire successional gradient in southern Switzerland we show that these two measures may be used to describe two complementary aspects of community structure, such as the mean and the dispersion of functional traits within a given species assemblage. While CWM can be adequately used to summarize shifts in mean trait values within communities due to environmental selection for certain functional traits, the Rao coefficient can be effectively applied to analyze patterns of trait convergence or divergence compared to a random expectation.

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Section: Discussionmentioning

confidence: 99%

Section: Measuring Single-trait Diversitymentioning

confidence: 99%

CWM and Rao’s quadratic diversity: a unified framework for functional ecology

2011

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“…We used the Sørensen index (bsor; Legendre & Legendre, 1998) to calculate pairwise dissimilarity in species composition between all samples (276 dissimilarity values). The distance matrix among species functional traits was calculated using a modification of Gower distance, the coefficient of distance for mixed variables proposed by Pavoine et al (2009). This distance matrix was transformed into a dendrogram using the method of average linkage clustering (UPGMA).…”

Section: Discussionmentioning

confidence: 99%

Patterns in species and functional dissimilarity: insights from periphytic algae in subtropical floodplain lakes

2015

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Understanding spatial and temporal changes in species composition has long demanded the attention of ecologists. However, only recently questions related to changes in species functional traits have been investigated. We explored patterns of species and functional dissimilarity of periphytic algae at six lakes sampled over a year across a subtropical floodplain. We evaluated the importance of turnover and nestedness components across space and time; the influence of environmental dissimilarity, spatial distance, and time on species and functional dissimilarity; and whether functional dissimilarity results from nonstochastic assembly processes. We used six functional traits to describe 155 species. Functional dissimilarity was estimated by functional dendrograms, and stochasticity was evaluated using null models. The turnover component was greater than nestedness for species and functional dissimilarity. Environmental dissimilarity, spatial distance, or time did not significantly explain species or functional dissimilarity. However, functional dissimilarity was significantly greater than expected given the observed species dissimilarity. The main finding of this study is that community assembly was deterministic with respect to traits. Further, each lake contributed similarly to the overall species and traits pool. These results highlight the importance of comparing species and functional dissimilarities to reach a better understanding of the organization of periphytic algal communities.

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“…Gower's mixed-variable distance coefficient was used to calculate functional distance among species (Pavoine et al 2009). This index can integrate quantitative, categorical and fuzzy traits.…”

Section: Functional Phylogenetic and Taxonomic Diversitymentioning

confidence: 99%

Conservation along a hotspot rim: spiders in Brazilian coastal restingas

et al. 2014

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Protected areas are essential for the maintenance of biodiversity, but defining criteria for prioritizing areas to conserve is not an easy task. In general, selection has been based on species richness and endemism of plants and vertebrates; however, these do not necessarily match invertebrate data, hence the need of using other groups in conservation prioritization. Moreover, species richness represents one of several biodiversity facets and does not subsume other facets such as functional and phylogenetic diversity. Restingas are coastal ecosystems within the Atlantic Forest biome, one of the World's biodiversity hotspots. We investigated whether there is congruence between three different spider biodiversity facets: functional (FD, the variety of functional traits of species), phylogenetic (PD, the evolutionary distinctness of species), and taxonomic (TD, the number and the Communicated by Dirk Sven Schmeller.Electronic supplementary material The online version of this article (relative abundance of species), and whether currently protected restingas are effective in protecting these facets. We studied vegetation-living spider communities in 11 restingas along 2,000 km of the Brazilian coast. We found that no value of any biodiversity facet was higher in protected restingas compared with unprotected ones. We demonstrated low congruence between the three biodiversity facets, so that the use of TD as a surrogate of other facets is unwarranted. Whilst some protected restingas hold high values of spider TD, other still unprotected areas present high PD or FD. This result suggests that conservation efforts should be extended to every remaining restinga because they are unique sites to at least one spider biodiversity facet. In particular, we recommend three unprotected restingas as high priorities in future conservation plans based on spider diversity, which corroborate findings for plants and vertebrates in the same sites.

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On the challenge of treating various types of variables: application for improving the measurement of functional diversity

Cited by 133 publications

References 41 publications

CWM and Rao’s quadratic diversity: a unified framework for functional ecology

CWM and Rao’s quadratic diversity: a unified framework for functional ecology

Patterns in species and functional dissimilarity: insights from periphytic algae in subtropical floodplain lakes

Conservation along a hotspot rim: spiders in Brazilian coastal restingas

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