Modelling influences of local and climatic factors on the occurrence and abundance of non-marine ostracods (Crustacea: Ostracoda) across Patagonia (Argentina)

In this study, we tested the significance of environmental influences on non-marine ostracod communities at high taxonomic levels across Patagonia, Argentina. We used a dataset compiled from 243 Patagonian freshwater bodies, representing an area of ~ 900,000 km 2 and covering the main local and climatic gradients. We applied generalized linear models to test the effects of hydroperiod, local and climatic variables on the occurrence and abundance of Ostracoda, and the occurrence of the most frequent families (i.e., Cyprididae, Ilyocyprididae and Limnocytheridae). We found ostracods in 77% of the total sampled sites, driven mainly by dissolved oxygen levels and water temperature (local variables) as well as precipitation and air temperature (climatic variables). Specifically, warmer winters and dryer climates favored ostracod occurrences, which covered wide ecological ranges, such as peat bogs or high-altitude wetlands. For the Ilyocyprididae and Limnocytheridae families, precipitation and pH were important predictors of their occurrence. Furthermore, wind speed, nutrient levels and water depth had positive effects on ostracod abundance. This updated Patagonian freshwater dataset contributes towards filling those knowledge gaps related to the habitat suitability of ostracods communities in this vast region. Our findings could help us understand the past and future responses of ostracods to environmental changes.