Climate, disturbances, and human activities as drivers of tropical forest and savanna dynamics across temporal scales
Tropical forests and savannas are often described as alternative stable states maintained by feedbacks between disturbances (especially fire) and vegetation structure, although the strength and generality of these feedbacks remain debated. Their limited representation in vegetation models may lead to oversimplified projections and, in some cases, misleading management and conservation strategies. Understanding these dynamics requires looking across time. Ecosystem responses to climate variability, disturbances and land-use change provide insights into these feedbacks, particularly by identifying phases of vegetation resilience as well as conditions that lead to abrupt and potentially irreversible transitions between states. In this seminar, I present results from modern ecosystem dynamics and palaeoecological records, together with ongoing efforts to refine past environmental reconstructions. Overall, this research contributes to a better understanding of the mechanisms underlying ecosystem stability and transitions in the tropics.
I am a CNRS researcher based at CEREGE (the Research and Teaching Centre in Environmental Geosciences, Aix-en-Provence, France). My work focuses on the distribution and long-term dynamics of tropical forests and savannas, with a particular emphasis on Central Africa. I develop an interdisciplinary research combining paleoclimatology, paleoecology, historical ecology, GIS, and modelling to investigate how grass-dominated ecosystems responded to environmental changes during the Holocene, and how they may respond to ongoing global change.
