ICG2022-20

Wildfires and Soil Erosion
Conveners: Lea Wittenberg, Luciano Lourenço, Fantina Tedim, António Bento-Gonçalves

Fire is a (semi) natural part of the disturbance regime that has shaped the earth's surface for millennia. Once established, fires shaped the landscape of most terrestrial ecosystems via vegetation structure and soil-forming processes. In recent years, however, frequent wildfires have erupted globally, scorching places that rarely burned before. Fires intensify runoff and erosion by removing vegetation, changing soil properties, and providing erodible sediment and easily-transported ash. Accelerated rates of fire-induced erosion might trigger a rapid redistribution of sediment and pyrogenic debris, affect landscape evolution, nutrient cycling and ecologic dynamics, and pose many environmental, social and economic implications. Given the complexity of the interacting (natural and anthropogenically-driven) forces, fire-induced erosion varies markedly across spatio-temporal scales. A broad array of fire-induced hydrologic and sedimentologic responses ranging from no effect to deadly floods has been documented in various places worldwide. Furthermore, the progression of ecosystem recovery may last decades, during which the soil remains exposed to elevated erosion, considerably higher than the natural soil formation rates. Despite numerous studies across all spatial scales, our understanding of the processes and mechanisms contributing to post-fire runoff and erosion is limited. This focus is essential given the rapid changes in fire regimes due to multiple interacting global change drivers such as climate change, land use, and direct human impacts via ignition and suppression. A better understanding of these processes might lead to improved predictive capabilities of post-wildfire erosion and facilitate mitigation and management strategies. Therefore, this session highlights research focused on the response of earth surface systems to wildfire, including, but not limited to, the alteration of soils and sediments across large ranges of spatial and temporal scales. We welcome studies that provide insight into the causes, impacts, and/or management of post-wildfire soil erosion; we encourage contributions that creatively highlight field or laboratory experiments using novel techniques and methodologies.