Assessing changes in post-fire vegetation resilience in Mediterranean basin over the past 22 years

Fire is an integral component of ecological dynamics, playing an important role in biome distribution and biomass variability. Nonetheless, fires can also pose a  threat to both ecosystems and humans, by imposing severe economic and social consequences, and potentially contributing to biodiversity loss, carbon loss and soil erosion, whose effects can last from months to years.

The Mediterranean basin is a fire-prone region where vegetation is in general well adapted to fire, with several species showing resistance to fire itself or being able to recover quickly following fire events. However, as a consequence of climate change, more intense and frequent summer hot and dry conditions are expected to occur, which can promote more frequent and severe wildfires, with return periods potentially outpacing recovery times. Understanding recovery dynamics is therefore crucial to assess the impact of changing fire regimes in ecological dynamics and stability of ecosystems. 

In our study, we use the “Enhanced Vegetation Index” (EVI), remotely-sensed by MODIS sensor with a temporal span of 22 years, to evaluate vegetation dynamics before, during and following large fire seasons. We use a mono-parametric recovery model to assess recovery times in different burn scars across the Mediterranean basin, covering different fire regimes and land cover types. We find a tendency for slower recovery in areas that burned more often, which may indicate a decrease in ecosystems’ resilience in the past 22 years.

This study was performed under the frameworks of the 2021 FirEUrisk project (funded by European Union’s Horizon 2020 research and innovation programme under the Grant Agreement no. 101003890) and of the PhD MIT Portugal MPP2030-FCT programme (Grant no.22405886350).