Tropical rainforests are key ecosystems for livelihoods, carbon storage and biodiversity. They are adapted to a relatively moist and thermally stable climate and are therefore suggested to be particularly vulnerable to climate change. Unusually warm and dry conditions during recent decades have caused shifts in tree community composition and declines in forest carbon sink. These negative effects are thought to be caused by increasing tree mortality rather than by decreasing productivity of living trees. Drought- and heat-induced tree mortality is generally triggered by a catastrophic failure of the vascular system transporting water from roots to leaves. Thorough understanding of tree hydraulics is therefore crucial for reliable projections of tree and forest responses to climate change. However, knowledge on tree hydraulics and the mechanisms behind tree mortality is currently limited for tropical species, hampering predictions of the fate of this biome in a changing climate. During this talk, I will introduce basic concepts on tree
hydraulic functioning and present some of the current knowledge on plant adaptive strategies to drought. I will tackle two main questions: 1) Why are certain species more vulnerable than others? 2) Will adjustments of specie’s hydraulic functioning minimize their vulnerability to heat and drought? To do so, I will focus on both lowland and montane tropical forests, including
results from a recent study conducted in Rwanda within the Rwanda-TREE project.
20 сен 2024
