Burned soils in Europe require attention: post fire soil erosion is long lasting

Annually, millions of hectares of land are affected by wildfires worldwide, disrupting ecosystems functioning by affecting on-site vegetation, soil, and above- and belowground biodiversity, but also triggering erosive off-site impacts such as water-bodies contamination or mudflows. Wildfires consist in an environmental problem with a global dimension, and its occurrence at EU scale is well documented.

However, the estimation of the indirect impacts of wildfires, such as increased soil erosion at wider scales, are still lacking. In this study, we present a soil erosion assessment following the 2017's wildfires at the European scale with the RUSLE model, including an analysis of vegetation recovery and soil erosion mitigation potential (Vieira et al., 2023).

Results indicate a sharp increase in soil losses with 19.4 million Mg additional erosion in the first year following the wildfire when compared to unburned conditions. Over five years, 44 million Mg additional soil losses were estimated, and 46% of the burned area presented no signs of full recovery. Post-fire mitigation with mulching could attenuate these impacts by 63–77%, reducing soil erosion to background levels by the 4th post-fire year. Soil erosion risk based mitigation strategies revealed near optimal mitigation potential when compared with thoses based on burn severity alone.

Our insights may help identifying target policies to reduce land degradation, as identified in the European Union Soil, Forest, and Biodiversity strategies.

 

Vieira, D.C.S., Borrelli, P., Jahanianfard, D., Benali, A., Scarpa, S., Panagos, P., 2023. Wildfires in Europe: Burned soils require attention. Environmental Research, 2023, 217, 114936. https://doi.org/10.1016/j.envres.2022.114936