In recent decades, forest vulnerability is rapidly increasing worldwide; forest dieback episodes have been recorded in all biomes affecting different tree species. In particular, several cases of widespread dieback and increased mortality rates have been described for tree and shrub species. These dieback cases are revealing the high vulnerability of some forests, manifested as a loss in tree vigour (leaf shedding, canopy and shoot dieback), growth decline and sometimes tree death. Such dieback phenomena seem to be a response to the rapid temperatures rise and associated drying trends. These cases, extended to a larger scale, can have the potential to rapidly alter forest ecosystem services, with important implications on the carbon-water balance, plant communities and tree population dynamics.
This session focuses on efforts to improve our understanding on how forest ecosystems respond to changes in climate and to increasing occurrence of extreme events such as heat waves and severe drought stress. In particular, there is increasing awareness on the need to evaluate which functional and structural traits make some tree species more prone to drought-induced dieback. Contributions include both observational, theoretical and as well as experimental studies, spanning a range of different biomes, scales and conditions. We further aim at promoting and actively seeking interdisciplinary collaborations with the international
global monitoring network on forest conditions (www.tree-mortality.net).