Studying geo-ecological succession in the deglaciating Alps and Andes combining ground NIR camera and satellite imagery with field data

Abstract:

Ecosystem development in recently deglaciated landscapes is usually studied over wider areas through satellite imagery or over smaller areas using in situ floristic evaluations. Each approach has strengths and limitations: satellite imagery is recurrent and covers large areas, but it lacks fine resolution, and field data collection has the fine resolution but lacks the breadth and is laborious. Here, we couple field data collection and satellite analysis to study the distribution and composition of pioneer alpine communities in glacier forelands. For a total of nine proglacial landscapes distributed between the Alps (France and Switzerland) and the Tropical Andes (Peru) we combined imagery from multiples sources (Pleiades, Sentinel, Landsat) with ground land cover data using a ground infrared camera and floristic evaluation to test for long term (1952-2018) primary geo-ecological succession in the context of recent climate change. We use the normalized difference vegetation index (NDVI) to assess vegetation development, predict biomass, and to connect field observed variables—i.e., species richness, plant cover, and soil properties—with global ecosystem functioning and services and upscale local patterns to regional processes. In addition, this approach allows us to couple the space for time substitution approach with geomorphological dynamics and landforms. We hypothesize that spatial heterogeneity will reflect gradual successional trajectories related to small variations in physical habitat conditions and abiotic and biotic processes combine to drive the pioneer stages of plant succession after glacier retreat.