Distinct Amphibian Elevational and Seasonal Phylogenetic Structures Are Determined by Microhabitat Variables in Temperate Montane Streams

SIMPLE SUMMARY: Phylogenetic structure can be used to understand various ecological patterns. The main objective of the present study was to understand the elevational and seasonal amphibian phylogenetic structures in temperate montane streams. This study was conducted in 13 streams located in lowland and highland sites of Tianping mountain, China, in April, June, August, and October 2017, separately. We found that the elevational spatial patterns were not significantly different, but the seasonal temporal patterns differed significantly for amphibian phylogenetic structures, associated with the variation of microhabitat variables. ABSTRACT: Phylogenetic structure is a key facet of biodiversity, reflecting the evolutionary history of species, and thus can be used to understand various ecological patterns. Although amphibian phylogenetic structures have been tested across space and time separately, simultaneous quantifications are still needed. In the present study, amphibians in streams of Tianping mountain, China, were selected as the model to investigate their elevational spatial and seasonal temporal patterns of phylogenetic diversity. Specifically, 13 streams located in lowland and highland sites were sampled for amphibians and measured for microhabitat variables in April, June, August, and October 2017, separately. Four phylogenetic structural indices, including Faith’s PD, standardized effect size (SES) of Faith’s PD, mean pairwise phylogenetic distance index (MPD), and SES.MPD, were calculated. Our results revealed that amphibian phylogenetic patterns were not significantly different between lowland and highland sites, but differed significantly between four seasons, associated with distinct community assembly rules (phylogenetically overdispersed vs. phylogenetically clustered). Importantly, these patterns were strongly determined by microhabitat variables such as rock cover, water temperature, and water depth. Our results provide fundamental knowledge to better protect amphibian diversity. Both elevational and seasonal variations are important to understanding the general patterns of amphibian community assembly rules.