Drivers of parasite β-diversity among anuran hosts depend on scale, realm and parasite group

A robust understanding of what drives parasite beta-diversity is an essential step towards explaining what limits pathogens' geographical spread. We used a novel global dataset (latitude -39.8 to 61.05 and longitude -117.84 to 151.49) on helminths of anurans to investigate how the relative roles of climate, host composition and spatial distance to parasite beta-diversity vary with spatial scale (global, Nearctic and Neotropical), parasite group (nematodes and trematodes) and host taxonomic subset (family). We found that spatial distance is the most important driver of parasite beta-diversity at the global scale. Additionally, we showed that the relative effects of climate concerning distance increase at the regional scale when compared with the global scale and that trematodes are generally more responsive to climate than nematodes. Unlike previous studies done at the regional scale, we did not find an effect of host composition on parasite beta-diversity. Our study presents a new contribution to parasite macroecological theory, evidencing spatial and taxonomic contingencies of parasite beta-diversity patterns, which are related to the zoogeographical realm and host taxonomic subset, respectively. This article is part of the theme issue 'Infectious disease macroecology: parasite diversity and dynamics across the globe'.

Automated summary

Understanding the drivers of parasite beta-diversity is crucial in explaining the limitations of pathogen geographical spread. A global study on helminths of anurans revealed that spatial distance is the key factor influencing parasite beta-diversity, with climate playing a bigger role at regional scales. Trematodes were found to be more responsive to climate changes compared to nematodes. Host composition did not show significant effects on parasite beta-diversity.