Diversity of planktonic and benthic communities in the high‐altitude Salar de Pedernales basin, Atacama Desert, Chile

Abstract

Salar de Pedernales basin is located at 3370 meters above sea level in the Atacama Desert, Chile, covering an area of 3620km2. This ecosystem is characterized by high exposure to ultraviolet radiation, low humidity, huge variations in ion content andextreme thermal gradients. Despite these extreme conditions, it has a rich fauna and flora. However, the aquatic biodiversityin the basin remains poorly documented. Our study assessed compositional changes of planktonic and benthic communitiesacross several salt flats (Pedernales S-O, Piedra Parada, La Laguna), natural water courses (wetland and creeks), an artificialstream and lagoon (Pedernales N-E), and their relationship with local physicochemical parameters. Our results show that theSalar de Pedernales basin is a highly heterogeneous ecosystem principally influenced by conductivity, pH, and major ions.Community diversity was high at all locations except for the artificial stream. Microalgae were spatially similar with majorchanges observed in the disturbed habitats. The composition of the invertebrate communities strongly varied among habitats butdisplayed distinct composition in the perturbed ones (Salar Pedernales N-E). Distance-based redundancy analysis revealed thatphytoplankton and benthos composition were driven by changes in trace metals and nitrate, whereas zooplankton communitycomposition was mainly related to osmotic stress. Our data highlight the remarkable biodiversity of the natural water bodiesof the Salar de Pedernales basin and the potential effects of anthropogenic perturbations on the biota in these extreme habitats