Vulnerability of forest ecosystems to fire in the French Alps

• DOI: 10.1007/s10342-019-01206-1
• Publication Date: 2019-06-20T07:24:17Z
• Authors: Sylvain Dupire; Thomas Curt; Sylvain Bigot; Thibaut Fréjaville
• Keywords: [SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture; environment/Bioclimatology; 550; Vulnerability; 01 natural sciences; Tree mortality; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems; [SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry; [SDV.EE.ECO] Life Sciences [q-bio]/Ecology, environment/Ecosystems; [SPI.GCIV.RISQ]Engineering Sciences [physics]/Civil Engineering/Risques; Climate change; [SPI.GCIV.RISQ] Engineering Sciences [physics]/Civil Engineering/Risques; 0105 earth and related environmental sciences; 580; Alps; forestry; Forest fire; 15. Life on land; [SDE.BE] Environmental Sciences/Biodiversity and Ecology; [SDV.EE.BIO] Life Sciences [q-bio]/Ecology, environment/Bioclimatology; 13. Climate action; [SDV.EE.BIO]Life Sciences [q-bio]/Ecology; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; Mountain forest; [SDV.SA.SF] Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.EE.BIO]Life Sciences [q-bio]/Ecology, environment/Bioclimatology; environment/Ecosystems

Forest fires are expected to be more frequent and more intense with climate change, including in temperate and mountain forest ecosystems. In the Alps, forest vulnerability to fire resulting from interactions between climate, fuel types, vegetation structure and tree resistance to fire is little understood. This paper aims at identifying trends in the vulnerability of Alpine forest ecosystems to fire at different scales (tree species, stand level and biogeographic level) and according to three different climatic conditions (cold season, average summer and extremely dry summer). To explore Alpine forest vulnerability to fire, we used surface fuel measurements, forest inventory and fire weather data to simulate fire behaviour and ultimately post-fire tree mortality across 4438 forest plots in the French Alps. The results showed that cold season fires (about 50% of the fires in the French Alps) have a limited impact except on low-elevation forests of the Southern Alps (mainly Oak, Scots pine). In average summer conditions, mixed and broadleaved forests of low elevations suffer the highest mortality rates (up to 75% in coppices). Finally, summer fires occurring in extremely dry conditions promote high mortality across all forest communities. Lowest mortality rates were observed in high forest stands composed of tree species presenting adaptation to surface fires (e.g. thick bark, high canopy) such as Larch forests of the internal Alps. This study provides insights on the vulnerability of the main tree species and forest ecosystems of the French Alps useful for the adaptation of forest management practices to climate changes.