DRYTIP – understanding drought-induced changes in ecosystem functioning across Europe

Abstract

Terrestrial ecosystems are increasingly confronted with environmental changes such as climate change, natural disasters, or anthropogenic disturbances. Prolonged droughts, heat waves and increasing aridity are generally considered major consequences of ongoing global climate change and are expected to produce widespread changes in key ecosystem attributes, functions, and dynamics. Europe has been heavily affected by consecutive and increasingly severe droughts in the past decades, leading to large-scale vegetation die-offs and land degradation. This enhanced frequency in the past, combined with potential impacts of future climate change, makes it important to understand how these droughts affect ecosystem stability functioning and induce changes in ecosystem functioning, which is the aim of the DRYTIP project.  As carbon gain in terrestrial ecosystems is a compromise between photosynthesis and transpiration, a ratio that is also known as water-use-efficiency (WUE), assessing changes in WUE plays a key role in assessing changes in terrestrial ecosystem functioning. We used a remote sensing-based approach to describe changes in ecosystem functioning (similar to the approach suggested in Horion et al. (2019)) across Europe between 2000 and 2023.  We investigate how the severity and duration of droughts relates to the intensity of the change in ecosystem functioning, as well as what are the characteristics of ecosystems where abrupt changes in WUE were observed as a result of drought. We expect to find regional differences in the WUE response scenarios to drought and we will explore the underlying ecosystem conditions in exemplary cases. We finally hypothesise that these differences in ecosystem response to drought can be linked to ecosystem resilience.  We are looking forward to presenting and discussing preliminary results at the General Assembly.