Spatial and temporal heterogeneity of depositional environment and vegetational cover in a salt flat of the Lickan Antay Territory of Toconao,Northern Chile

Abstract

High-altitude wetlands (HAWs) are important aquatic ecosystems located more than 3000 m a.s.l. in the Andean Altiplano–Puna plateau that include springs, meadows, peatlands, saline lakes, and salt flats. This region experiences arid climate conditions with high evaporation rates, extreme daily and annual thermal variations, intense winds, and exceptionally high radiation levels, creating harsh conditions for life. HAWs depend hydrologically on groundwater and inputs from the scarce rainfalls, streams, rivers, or snowmelt, making them unique to the Andean Altiplano landscape. Since pre-Hispanic times, they have provided essential ecosystem, social, and cultural functions in arid zones. In this study, the spatial heterogeneity of surface sediments in Salar de Quisquiro-Loyoques, in the Puna plateau of northern Chile, was examined. Through an integrated analysis of the normalized difference vegetation index (NDVI) and the normalized difference water index (NDWI) anomalies over the last 30 years supplemented by narratives from the Lickan Antay Community of Toconao about wet and arid events in the Quisquiro wetland, its relation to current and historical processes driven by exogenous forces was examined. Depositional conditions facilitate the formation or entry of sediments into these shallow water environments, making them highly dynamic. Differences in mineralogical, chemical, and magnetic properties were observed in inter- and intra-sampling points, where the salt flat was the most heterogeneous sub-environment analyzed. A close relationship between precipitation and water availability, and vegetation cover is suggested. Given the current potential for increasing non-metallic mining prospecting in the region, it is necessary to highlight the territorial rights, autonomy, and claims of the indigenous communities, who have preserved HAWs through their ancient identification with the territory and the use and comprehensive cultural and management practices in the past and at present.