The effect of spatial configuration of habitat capacity on β diversity

Abstract

Abstract. Patterns of b diversity are commonly used to infer underlying ecological processes. In this study, we examined the effect of spatial configuration of habitat capacity on different metrics of b diversity, i.e., b diversity measured as turnover and as variation. For b diversity as turnover, a monotonic species spatial turnover pattern is typically considered as a benchmark for species distributions driven only by dispersal process. Deviations from a monotonic curve are attributed to local environmental filtering (i.e., the same environmental factors affecting different species differently). However, we found nonmonotonicity in species spatial turnover in models without environmental filtering effect. This nonmonotonicity was caused by variation in a diversity, introduced by spatial configuration of habitat capacity. After applying a recent null-model approach-designed to tease out the effect of variation in a diversity-species spatial turnover remained non-monotonic. This non-monotonicity makes it problematic to use species spatial turnover to infer the underlying processes for species distribution, i.e., whether it is driven by environmental filtering or dispersal processes. Spatial configuration of habitat capacity also influences landscape connectivity. Small-habitat capacity sites may constrain movements of organisms (i.e., dispersal) between sites supporting high capacity habitats. We showed that in a landscape where smallhabitat capacity sites were located in positions important for dispersal (e.g., in the center as opposed to on the edge of a landscape) has a higher spatial variation of species composition, hence, higher b diversity. Ecologists who use different measures of b diversity should be aware of these effects introduced by spatial configuration of habitat capacity.

Convergent diversity and trait composition in temporary streams and ponds

“…It has been suggested to use Chao similarity to make among‐site comparisons because in a simulation study turnover beta diversity patterns may be influenced by differences in habitat capacity among sites (Dong et al. ); however, our results were similar regardless of the similarity index employed.…”

“…Overall, ponds had lower trait dissimilarity (mean 0.28) than streams (mean 0.43) indicating pond trait compositions were more similar and had less trait turnover between ponds. It has been suggested to use Chao similarity to make among-site comparisons because in a simulation study turnover beta diversity patterns may be influenced by differences in habitat capacity among sites (Dong et al 2015); however, our results were similar regardless of the similarity index employed.…”

Interpreting beta‐diversity components over time to conserve metacommunities in highly dynamic ecosystems

“…; Dong et al. ). Third, the covariation between beta diversity components may fluctuate over time in response to environmental variation (Angeler ; Ruhí et al.…”

“…Second, both intrinsic and extrinsic factors (e.g., dispersal strength of organisms, and habitat connectivity and heterogeneity) may influence these processes independently (Heino 2013). For instance, dispersal-driven homogenization or mass effects may reduce replacements (Mouquet & Loreau 2003), low dispersal capacities may increase them via stochastic colonization and priority effects (Vanschoenwinkel et al 2013), and habitat capacity may influence richness gradients (Chase et al 2011;Dong et al 2015). Third, the covariation between beta diversity components may fluctuate over time in response to environmental variation (Angeler 2013;Ruhí et al 2015;Datry et al 2016a).…”

Partitioning β-diversity reveals that invasions and extinctions promote the biotic homogenization of Chilean freshwater fish fauna

“…Analysis based on β-diversity are more adequate to evaluate biotic homogenization [ 43 – 45 ] because it is considered that changes in β-diversity respond to two different phenomena: species nestedness and turnover [ 43 – 45 , 48 , 49 ]. The nestedness corresponds to β-diversity’s component due to changes by gain or loss of species among samples [ 44 – 47 ], while the species turnover can be defined as the ‘true’ replacement of species among biotas [ 49 ], as result of environmental and geographical limitations that have been established over time [ 43 , 50 , 51 ]. Thus, the rationale of approaches based on β-diversity is that species widely distributed provide a decreased β-diversity among assemblages, evidencing ultimately, the role of turnover and nestedness as spatial processes underlying biotic homogenization.…”