Temporary ponds are among the most sensitive aquatic habitats to climate change. Their microbial communities have crucial roles in food webs and biogeochemical cycling, yet how their communities are assembled along environmental gradients is still understudied. This study aimed to reveal the environmental drivers of diversity (OTU-based richness, evenness, and phylogenetic diversity) and community composition from a network of saline temporary ponds, soda pans, in two consecutive spring seasons characterized by contrasting weather conditions. We used DNA-based molecular methods to investigate microbial community composition. We tested the effect of environmental variables on the diversity of prokaryotic (Bacteria, Cyanobacteria) and microeukaryotic functional groups (ciliates, heterotrophic flagellates and nanoflagellates, fungi, phytoplankton) within and across the years. Conductivity and the concentration of total suspended solids and phosphorus were the most important environmental variables affecting diversity patterns in all functional groups. Environmental conditions were harsher and they also had a stronger impact on community composition in the dry spring. Our results imply that these conditions, which are becoming more frequent with climate change, have a negative effect on microbial diversity in temporary saline ponds. This eventually might translate into community-level shifts across trophic groups with changing local conditions with implications for ecosystem functioning.

Primary Presenter: Zsuzsanna Márton, Institute of Aquatic Ecology, Centre for Ecological Research (mzsuzsi06@gmail.com)

Authors:

Zsuzsanna Marton, Institute of Aquatic Ecology, Centre for Ecological Research; National Multidisciplinary Laboratory for Climate Change, Centre for Ecological Research; Doctoral School of Environmental Sciences, ELTE Eotvos Lorand University  ()

Beata Szabo, Institute of Aquatic Ecology, Centre for Ecological Research; National Multidisciplinary Laboratory for Climate Change, Centre for Ecological Research,  ()

Csaba Vad, Institute of Aquatic Ecology, Centre for Ecological Research; National Multidisciplinary Laboratory for Climate Change, Centre for Ecological Research; Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven  ()

Karoly Palffy, Institute of Aquatic Ecology, Centre for Ecological Research; National Multidisciplinary Laboratory for Climate Change, Centre for Ecological Research  ()

Zsofia Horvath, Institute of Aquatic Ecology, Centre for Ecological Research; National Multidisciplinary Laboratory for Climate Change, Centre for Ecological Research; Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven  ()