The role of local environmental heterogeneity in shaping soil mesofauna communities of Argentine high Andean wetlands

Abstract

In the Argentine Puna, a particular type of wetlands called vegas are considered unique, as they are the main biodiversity hotspots in this arid high-elevation environment. Also, they provide essential ecosystem services. Despite their ecological significance, these ecosystems remain poorly studied. Particularly soil mesofauna, which play critical roles in nutrient cycling and organic matter dynamics, remain to be explored. We investigated the composition, abundance, and richness of taxa and feeding guilds of soil mesofauna communities across 10 vegas. These wetlands were distributed along an environmental gradient, in an elevation range of 3 323–4 748 m a.s.l., where we analysed soil properties and plant communities. We collected a total of 5 239 invertebrates, from which Acari was the most abundant group, followed by Collembola. Regarding feeding guilds, detritivores and predators dominated soil mesofauna communities. Variability in taxa abundance and richness was strongly influenced by local soil properties, such as organic matter, carbon-to-nitrogen ratio, and phosphorus content, as well as plant community attributes, particularly cushion plant cover. However, no soil or vegetation variables explained the differences in taxa identity across vegas. These findings highlight the critical role of local heterogeneity in shaping soil mesofauna communities and provide the first insights into these understudied ecosystems.