Exploring the Resilience of Playa Lake Ecosystems to Climate Change: A Microbial Perspective

Playa lakes, ephemeral water bodies found in arid and semi-arid regions, are increasingly impacted by climate change. The representative Mexican playa lake Atotonilco has experiences significant water volume decline, leading to higher salinity and shifts in microbial composition. Its sensitivity to drought highlights its vulnerability, making it a valuable model for studying climate change effects on ephemeral aquatic ecosystems. This study investigated the dynamics of physicochemical conditions, the responses of the microbial communities and their contributions to key biogeochemical cycles. Notably, spatial disparities in physicochemical parameters were discerned between sampling locations within the lake and associated canals. The bacterial communities exhibited marked seasonal and depth-related differences. Pseudomonadota were the dominant phylum. The rainy season favored Bacillota, Actinomycetota, and specific other taxa like Campylobacterota, Limnohabitans and Planococcus, which were more abundant during the rainy season, indicating vulnerability to extreme environmental changes like desiccation. During the hot season, physicochemical parameters such as temperature, pH, and dissolved oxygen (DO) increased, promoting the growth of genera like Alishewanella, and Cyanobium_PCC-6307. Additionally, some genera were found to persist in the lake regardless of extreme environmental changes. This study represents a pioneering investigation of microbial dynamics in playa lakes, which remain understudied yet crucial for understanding the ecological impacts of climate change on ephemeral aquatic systems. By unveiling microbial adaptation mechanisms to extreme environmental shifts, the findings lay the groundwork for future studies and provide essential insights for the conservation and management of similar arid region ecosystems.