Interannual lake fluctuations in the Argentine Puna: relationships with its associated peatlands and climate change

CASAGRANDA, ELVIRA; NAVARRO, CARLOS; GRAU, H. RICARDO; IZQUIERDO, ANDREA E.

REGIONAL ENVIRONMENTAL CHANGE

SPRINGER HEIDELBERG

Año: 2019

1436-3798

High elevation ecosystems are likely more sensitive to climate change. But, due to paucity of instrumental records, such effectsare poorly studied, particularly in mountains outside Europe and North America. Here, we quantified water body area fluctuationsfor the last 32 years in 15 lakes spread over an area of 14.3 million ha in the Argentine Puna, through the classification ofLandsat images; and we quantified peatlands NDVI (a proxy of vegetation productivity) from MODIS images.We evaluated thepairwise similarity between lakes interannual fluctuations and their relationship with climate models (TRMM3B43 v7; CRU TS4.10) and potential controls (ENSO index); and the correlations between water body area and the NDVI variation of its associatedpeatlands. Lakes were grouped in two clusters defined by their synchronic water body area variability and these clusters definetwo main geographic zones: NE and SW. Consistent with previous observations of an overall aridization trend, water body areagenerally decreased but showed large variability among lakes. Peatlands productivity was more correlated with lake variabilitythan with modeled precipitation, and lake water body area was weakly related to indices of ENSO, providing an additional tool torelate local climate with continental and global climate models. The analysis shows that lake behavior is highly variable spatiallyand temporally, and that satellite-based monitoring is a valuable tool for assessing ecological conditions of wetlands in the region,characterized by the lack of climatic instrumental records; and to explore the vulnerability of wetlands to climate change.