Macroinvertebrates diversity patterns in the heterogeneous and increasingly dry Patagonian depressional wetlands

EPELE, LUIS BELTRAN; GRECH, MARTA GLADYS; MANZO, LUZ MARÍA; MACCHI, PABLO A.; DROMAZ, WALTER MAURICIO; MISERENDINO, MARÍA LAURA

Congreso; Joint Aquatic Sciences Meeting 2022; 2022

Wetlands are among the most valued habitats of the globe since they disproportionately contribute to people welfare and hold a large diversity of organisms, including macroinvertebrates which play crucial ecological roles. Depressional wetlands from Argentinian Patagonia (southern South America) are relatively little impacted by human activities, constituting ideal systems to test the importance of multiple-scale factors, as well as to track the effects of climate change on macroinvertebrates assemblages. Here we synthesized the results of 15 years studying depressional wetlands macroinvertebrates and their environmental drivers in the heterogeneous Patagonia. We found that main local drivers of macroinvertebrate diversity patterns include aquatic plant cover, dissolved oxygen, electric conductivity, nutrient availability, and geomorphological origin of the wetlands. On a regional scale, the maximum temperature of the hottest month would be the main driver, but westerly winds also seem to exert a significant effect on macroinvertebrates metacommunity structure. Moreover, wetlands existence and consequently their diversity are regionally driven by precipitation patterns, which abruptly shifted since 2010 leading to a “megadrought” period. For example, after just three years monitoring montane depressional wetlands (2020-2022) we already recorded species colonization of wetlands previously inhabited by macroinvertebrates due to snow accumulation. We expect profound impacts on wetland distribution, structure, and functioning in the forthcoming years, with consequent biodiversity loss. We suggest the establishment of more long-term monitoring programs that contribute to understanding the effects of climate change on Patagonian wetlands biodiversity.