Disentangling niche theory and beta diversity change

Abstract

Beta diversity describes the differences in species composition among communities. Changes in beta diversity over time are thought to be due to selection based on species' niche characteristics. For example, theory predicts that selection that favours habitat specialists will increase beta diversity. In practice, ecologists struggle to predict how beta diversity changes. To remedy this problem, we propose a novel solution that formally measures selection's effects on beta diversity. Using the Price equation, we show how change in beta diversity over time can be partitioned into fundamental mechanisms including selection among species, variable selection among communities, drift, and immigration. A key finding of our approach is that a species' short-term impact on beta diversity cannot be predicted using information on its long-term environmental requirements (i.e. its niche). We illustrate how our approach can be used to partition causes of diversity change in a montane tropical forest before and after an intense hurricane. Previous work in this system highlighted the resistance of habitat specialists and the recruitment of light-demanding species but was unable to quantify the importance of these effects on beta diversity. Using our approach, we show that changes in beta diversity were consistent with ecological drift. We use these results to highlight the opportunities presented by a synthesis of beta diversity and formal models of selection.

Partitioning the temporal changes in abundance‐based beta diversity into loss and gain components

“…Temporal partitioning of Hill-number-based beta diversity could thus give us a synthetic understanding of community dynamics. Exploring the potential connections between our method and other partitioning methods that are based on Hill numbers (Godsoe et al, 2021(Godsoe et al, , 2022 would also be an important way forward.…”

Species interactions and diversity: a unified framework using Hill numbers

“…This approach outlines each of the mechanisms described in (Vellend 2010) can be analysed, including speciation, drift and immigration. Extensions to Hill numbers and beta diversity can be found in (Frank and Godsoe 2020; Godsoe et al 2022). Though the development of partitions for diversity change are relatively recent, these techniques draw on a rich literature of partition methods developed for other problems in ecology and evolution (Collins and Gardner 2009; Fox 2016; Loreau and Hector 2001).…”

“…Vellend’s framework emphasizes conceptual insights, but several authors have proposed empirical approaches inspired by this insight. For example, Godsoe et al (2022) showed how models of selection could be used to analyse changes in Shannon diversity at multiple spatial scales, while Tatsumi et al (2021)analysed changes in measures of diversity related to species richness. Though these approaches show promise we currently lack the ability to explicitly compare these explicit and implicit models of biotic interactions.…”

Partitioning the temporal changes in abundance-based beta diversity into loss and gain components

“…Temporal partitioning of Hill-number-based beta diversity could thus give us a synthetic understanding of community dynamics. Exploring the potential connections between our method and other partitioning methods that are based on Hill numbers (Godsoe et al, 2021(Godsoe et al, , 2022 would also be an important step forward.…”