The natural distribution of forests on Earth is determined to a large extent by climate conditions. This implies that in the face of global climatic change large new areas will become suitable for forest, while at the same time extensive areas of existing forest may become unstable, in the sense that even in the absence of human pressures they may turn into savanna-like or treeless vegetation. It is becoming clear that in climate zones ranging from the boreal to the tropics such shifts can have the character of critical transitions between alternative stable states.
We work with Milena Holmgren, Terry Chapin and Marina Hirota to improve the our understanding of the mechanisms that regulate such stability properties. We also search for ways to determine the resilience of forests from remote sensing data.