Changes in β‐diversity of saproxylic beetles along environmental gradients in temperate forests depend on species relative abundances

Abstract

Aim: Understanding the processes that structure biological communities along environmental gradients remains one of the main aims of ecological research. A leading question is how differences in species composition between sites, that is, β-diversity, change in habitats ordered along environmental gradients and how such changes vary with species relative abundances. The existing literature remains descriptive, mostly comparing communities from different parts of a gradient, but not tracking sequential changes of β-diversity along the entire gradient.Location: Temperate deciduous forests in Central Europe.Taxa: Saproxylic beetles. Methods:We applied a generalized concept of Hill numbers to data on the distribution of saproxylic beetles to test (i) whether community dissimilarities correlate with dissimilarities in major environmental variables (canopy openness, tree diameter and tree genus) and (ii) which mechanisms explain sequential changes of β-diversity along these environmental gradients. Furthermore, we illustrate changes in the mean (αdiversity) and total (γ-diversity) number of species along the gradients.Results: Dissimilarities in saproxylic beetle communities were positively correlated with dissimilarities in all studied environmental variables. Changes in β-diversity along the gradients differed for different weighting of rare, common and dominant species, with rare and dominant species always showing opposite trends. β-diversity increased simultaneously with increasing γ-diversity when weight was given to dominant species. On the other hand, β-diversity decreased when weight was given to rare species. Main conclusions:The different response of rare and dominant species indicates a similar importance of stochastic and deterministic processes in determining β-diversity.Although the changes in β-diversity detected along the environmental gradients were relatively slight, major community dissimilarities were found when comparing communities in different locations of the environmental gradients.

Different facets of alpha and beta diversity of benthic diatoms along stream watercourse in a large near‐natural catchment

“…For example, rare species may be more spatially restricted and have higher habitat specialization, so are much more vulnerable to environmental changes than common species (Benone et al., 2022 ). Furthermore, previous studies have found that dominant, common, and rare species can contribute different weights to the variation of beta diversity (Sebek et al., 2022 ) and altering species relative abundances and/or changes to the size of species pool can also influence local diversity variation (Blowes et al., 2022 ). Hence, these findings highlight the need for further research on the relative roles of common and rare species to biodiversity patterns in order to provide deeper insights into underlying mechanisms.…”

“…For instance, the relationship of beta diversity in different facets and different spatial or environmental scales (even less concerned) can help us understand the maintenance processes of biodiversity (Meynard et al., 2011 ). Additionally, increasing studies have found that differences in species relative abundance (i.e., common or rare species) or species evenness could also put importance on the stochastic and deterministic processes of beta diversity, which was another important component of diversity (Li et al., 2019 ; Sebek et al., 2022 ; Wilsey & Potvin, 2000 ). Furthermore, effective conservation strategies require comprehensive knowledge considering multiple facets of biodiversity, including alpha/beta components of species richness, taxonomic and functional diversity, and their relationships (Kang et al., 2018 ).…”

Native diversity contributes to composition heterogeneity of exotic floras

“…First, diverse native communities with fuller niche partitioning and lower resource availability may have limited exotic establishment and propagule production. Some studies show that beta diversity correlates with species rarity, which may be caused by the poor reproductive performance of rare species (Hubbell, 1979; Sebek et al, 2022). Exotic plants often occur at multiple sites via high propagule pressure, which can lead to increased community similarity, especially during early establishment (Kempel et al, 2013; Muthukrishnan & Larkin, 2020).…”