Investigating post-wildfire effects in contrasted Mediterranean ecosystems

Abstract Purpose: This review examines the effects of wildfires in Mediterranean and contrasted ecosystems (e.g. in terms of topography, vegetation cover, wildfire history) through the prism of ecosystem components. This approach considers the multiple components of the ecosystem, including soils and sediments, water, and biota, as well as external stressors such as chemical contaminants, to assess the multiple impacts of wildfires. These impacts, which spread from upper to lower catchment areas, affect all ecosystem components, physical, biological, and functional, in a cumulative process along the entire trajectory. Their extent and nature depend on both the intrinsic characteristics of the environment, such as topography, vegetation cover, soil type, and hydrological connectivity, and the characteristics of the wildfire, including its intensity, severity, extent, and frequency. By investigating erosion processes, biodiversity changes and their impacts via environmental DNA analysis, the redistribution of fire retardants, and sediment transport, the aim is to provide a comprehensive understanding of wildfire effects. The main objective of the current review is to synthesize existing knowledge and to identify critical gaps in our understanding of the interactions between these factors, including wildfire, biodiversity, erosion, and contaminants. Methods: Relevant journal articles were extracted from the Clarivate Web of Science database as of September 9, 2025. A total of 161 publications were analyzed, and their findings were categorized into three thematic axes related to wildfire effects: post-wildfire erosion and sediment dynamics, biodiversity assessment using environmental DNA (eDNA), and the transfer of contaminants such as flame retardants and Polycyclic Aromatic Hydrocarbons (PAHs). Results and Conclusion: The results highlighted the complex relationships between wildfire-induced erosion, sediment dynamics, biodiversity and the effects of contaminant transfers in impacted areas. Accordingly, the need to implement comprehensive long-term research, conducted over more than two decades and conducted at integrative spatial scales (e.g. at the catchment level), to improve our understanding of ecological connectivity, sediment transport dynamics, and the cumulative effects of wildfires is demonstrated.