USING BIOCLIMATIC INDICATORS TO ANALYSE THE PRESENCE OF CLIMATIC MISMATCHES AMONGST LOCAL AMPHIBIAN ASSEMBLAGES OF AMERICA

Abstract

Species are facing an ongoing struggle to keep up with rising temperatures. This is leading to a disequilibrium between species communities’ thermal tolerances and the magnitude of climatic warming. In cases where species fail to adapt to climatic shifts, they exhibit a lagged response and, therefore, accumulate a climatic debt. Current information is primarily focused on plant, insect, and bird communities in temperate regions. Here, we examine the variation of climatic lag amongst 80 amphibian assemblages from the Hylidae family across America. For our analyses, we calculated the climatic lag for each assemblage as the difference between community temperature indices (CTI) and average historical temperatures for both maximum and minimum values. Using generalized linear mixed models, we evaluated a potential set of variables driving climatic debt. Trends in assemblage responses were visible and varied across sites. Higher lag values were concentrated in southern provinces of America, suggesting that assemblages in these areas may face difficulty in adapting to increasing temperatures, hence lower thermal ranges. Tropical assemblages seemed to be adapting quicker, displaying less lag or, in some cases, climatic credit. However, out of all the tested variables, only changes in evenness and heterogeneity may have an impact on lag. These results could suggest that the scale of our investigation was too large, encouraging further analyses at a regional scale as well as additional research into the complex nature of climatic lag and the variables that shape the lag dynamics effect.