Climate change-induced background tree mortality is exacerbated towards the warm limits of the species ranges

Adrien Taccoen (1) , Christian Piedallu (1) , Ingrid Seynave (1) , Anne Gégout-Petit (2) , Jean-Claude Gégout (1)

1 SILVA - SILVA
2 IECL - Institut Élie Cartan de Lorraine

Key message : An influence of the recent changes in temperature or rainfall was demonstrated, increasing background tree mortality rates for 2/3 of the 12 studied tree species. Climate change-induced tree mortality was exacerbated towards the warm or dry limits of the species ranges, suggesting in these areas a progressive replacement by more xeric species. Context : Despite the identification of climate change effects on tree mortality in various biomes, the characterization of species-specific areas of vulnerability remains poorly understood. Aims : We sought to assess if the effects of temperature and rainfall changes on background tree mortality rates, which did not result from abrupt disturbances, were linked to climate change intensity only, or if they also depended on the tree’s location along climatic gradients. Methods : We modelled background mortality for 12 of the most common European tree species using 265,056 trees including 4384 dead trees from the French national forest inventory. To explain mortality, we considered variables linked to tree characteristics, stand attributes, logging intensity and site environmental characteristics, and climate change effects. Results : We found an influence of temperature and rainfall changes on 9 species out of 12. For 8 of them, climate change-induced tree mortality was exacerbated towards the warm or dry limits of the species ranges. Conclusion ; These results highlight that tree mortality varies according to the climate change intensity and the tree location along temperature and rainfall gradients. They strengthen the poleward and upward shifts of trees forecasted from climate envelope models for a large number of European tree species.

Mots clés: Climate warming; Vulnerability; Temperate forests; Temperature warming; Tree species niche; Tree species shifts

Domaines: Bioclimatologie; Sylviculture, foresterie; Applications [stat.AP]

Adrien Taccoen, Christian Piedallu, Ingrid Seynave, Anne Gégout-Petit, Jean-Claude Gégout. Climate change-induced background tree mortality is exacerbated towards the warm limits of the species ranges. Annals of Forest Science, 2022, 79 (1), pp.23. ⟨10.1186/s13595-022-01142-y⟩. ⟨hal-03694879⟩