Robust, data-driven bioregionalizations emerge from diversity concordance

Abstract

Aim: Despite the increasing interest in developing new bioregionalizations and assessing the most widely accepted biogeographic frameworks, no study to date has sought to systematically define a system of small bioregions nested within larger ones that better reflect the distribution and patterns of biodiversity. Here, we examine how an algorithmic, data-driven model of diversity patterns can lead to an ecologically interpretable hierarchy of bioregions. Location: Australia. Time period: Present. Major taxa studied: Terrestrial vertebrates and vascular plants. Methods: We compiled information on the biophysical characteristics and species occupancy of Australia′s geographic conservation units (bioregions). Then, using cluster analysis to identify groupings of bioregions representing optimal discrete-species areas, we evaluated what a hierarchical bioregionalization system would look like when based empirically on the within- and between-site diversity patterns across taxa. Within an information-analytical framework, we then assessed the degree to which the World Wildlife Fund′s (WWF) biomes and ecoregions and our suite of discrete-species areas are spatially associated and compared those results among bioregionalization scenarios. Results: Information on biodiversity patterns captured was moderate for WWF′s biomes (50–58% for birds′ beta, and plants′ alpha and beta diversity, of optimal discrete areas, respectively) and ecoregions (additional 4–25%). Our plants and vertebrate optimal areas retained more information on alpha and beta diversity across taxa, with the two algorithmically derived biogeographic scenarios sharing 86.5% of their within- and between-site diversity information. Notably, discrete-species areas for beta diversity were parsimonious with respect to those for alpha diversity. Main conclusions: Nested systems of bioregions must systematically account for the variation of species diversity across taxa if biodiversity research and conservation action are to be most effective across multiple spatial or temporal planning scales. By demonstrating an algorithmic rather than subjective method for defining bioregionalizations using species-diversity concordances, which reliably reflects the distributional patterns of multiple taxa, this work offers a valuable new tool for systematic conservation planning.

Complex ecological and socioeconomic impacts on medicinal plant diversity

“…Previous studies have shown that differences in spatial scales have different effects for evaluating diversity (Chisholm et al, 2018). However, our knowledge of bioregional-scale diversity is fragmented, creating barriers to systematic conservation planning, and knowledge gaps about diversity at spatial scales deserve more attention (Montalvo-Mancheno et al, 2020). Crawley and Harral proposed that at large spatial scales, species richness depends on the number of species and extinction rates.…”

Human land‐use changes the diets of sympatric native and invasive mammal species

“…We used the mammal community in Tasmania (Australia) as a case study to assess the impact of anthropogenic land-use on the architecture of food webs in an invaded community. Tasmania has a relatively uniformly distributed community of mammal species (Chiu-Werner A., Montalvo-Mancheno C.S., Driessen M., Jones M.E., unpublished data; Montalvo-Mancheno et al, 2021), but the abundance of each species varies geographically. For instance, the disease-induced decline of populations of the top predator and scavenger, the Tasmanian devil (Sarcophilus harrisii), has triggered a rise in feral cat (Felis catus) numbers through reduced competition and increased presence of carrion in the landscape (Cunningham et al, 2018(Cunningham et al, , 2020.…”