Beta redundancy for functional ecology

Abstract

1. Functional beta redundancy has been recently defined as the fraction of species dissimilarity between two plots not expressed by functional dissimilarity. As such, it summarizes to what degree the compositional differences between two plots mirror their functional differences.2. A fundamental condition to obtain an appropriate measure of functional beta redundancy is that the functional dissimilarity between the plots is always lower (or at least not higher) than the corresponding species dissimilarity. However, many of the extant measures of functional dissimilarity do not fulfil this requirement.3. To overcome this problem, a class of tree-based indices of functional dissimilarity that conform to the above 'redundancy property' has been recently proposed.However, functional dissimilarity measures need not necessarily be based on a hierarchical representation of the species functional relationships. 4. In this paper, we introduce an algorithmic index of functional dissimilarity that conforms to the redundancy property. Since it does not rely on a hierarchical species organization, the proposed index allows to calculate functional beta redundancy in a more suitable way to the non-hierarchical structure of the species functional relationships. The behaviour of the proposed measure is illustrated with data on the species functional turnover along real and simulated ecological gradients. K E Y W O R D S algorithmic measure, functional dissimilarity, local versus global scaling, redundancy property, standardized versus non-standardized coefficients | 1063 Methods in Ecology and Evoluঞon RICOTTA eT Al.

Cross-scale effects of land use on the functional composition of herbivorous insect communities

“…While their study was based on taxonomic data, it remains unclear how land-use intensity affects functional b-diversity, i.e. the functional dissimilarity among communities (Ricotta and Burrascano 2008). Functional diversity measures may, however, be better predictors for the functional consequences of land-use intensification than taxonomic measures (Laureto et al 2015).…”

Relative importance of deterministic and stochastic processes for beta diversity of bird assemblages in Yunnan, China

“…Many indices to assess the functional beta diversity among communities have been proposed (e.g., Anderson et al 2006, Ricotta and Burrascano 2008, Villéger et al 2011. We chose two widely used presence-absence weighted functional beta diversity metrics for the bird occurrence data in this study: the mean pairwise functional distance (D pw ) and the mean nearest functional neighbor distance (D nn ).…”

Niche differentiation along multiple functional‐trait dimensions contributes to high local diversity of Euphorbiaceae in a tropical tree assemblage

“…To test functional-trait turnover along environmental dimensions, we first calculated functional beta diversity between subplots at local scale on 20 m × 20 m. For each of the five trait dimensions, we calculated the functional dissimilarity between each pair of subplots using the trait distance (D pw ) of the four traits with the greatest centrality values and all functional traits (Ricotta & Burrascano, 2008).…”