Vegetation greenness and thermal heterogeneity as proxies of climate change resilience in Argentina

OLIVERA SILVEIRA EDUARDA; MARTINUZZI SEBASTIÁN; PIDGEON ANNA; MARTINEZ PASTUR GUILLERMO; LIZARRAGA LEONIDAS; POLITI NATALIA; RIVERA LUIS; OLAH ASHLEY; RADELOFF VOLKER

Congreso; North American Congress for Conservation Biology; 2020

Vegetation greenness and thermal conditions shape speciesranges due their influence on resources availability and physiology. Heterogeneityin vegetation greenness and temperature offer mobile species options from which toselect, and may contribute to resilience during extreme conditions. Remotesensing data allow wall-to-wall mapping of greenness and thermal habitatheterogeneity across broad scales. Our goal was to characterize vegetation greennessand thermal heterogeneity across Argentina?s,15 major ecoregions. To estimate vegetation greenness heterogeneity, using the Enhanced Vegetation Index (EVI) derivedfrom Landsat 8, we extracted the 90th EVI percentiles from 2013 to2018, and then calculated first order image texture standard deviation (STD)for each years within an 11 x 11 pixel moving window. For thermalheterogeneity, we assessed land surface temperature in warm and cold periods, fromBand 10 of the thermal infrared sensor of Landsat 8. We calculated the STD within11 x 11 pixel moving windows, and then calculated the median values. Vegetationgreenness heterogeneity was highest in the northeast, center and southwestareas of Argentina, mainly in ecoregions covered by forest or cropland. Thermalheterogeneity was greatest in areas of highest altitudes influenced by the relief.However, vegetation greenness and thermal spatial variability were weaklycorrelated (r = 0.22 based on warm data and r = 0.02 based on cold data). Our maps of vegetation greenness and thermalheterogeneity across Argentina identify potential climate refugia under extremeconditions, and can be useful for conservation planning.