Lecturer:  Prof. Ehud Meron, Ben-Gurion University of the Negev
Abstract:
Climate change and the development of drier climates threaten ecosystems’ health and the services they provide to humans. Understanding ecosystem response to drier climates may provide clues on improving their functioning and resilience. This response is likely to involve mechanisms operating at different levels of ecological organization. At the single-plant level, phenotypic changes can occur; at the population level, spatial patterns can form; and at the community level, community reassembly and biodiversity changes may take place. These mechanisms must affect one another, as stress relaxation by one mechanism weakens the driving forces of other mechanisms, but complex ecosystem responses involving coupled mechanisms have hardly been studied. In this talk I will focus on the interplay between phenotypic changes and spatial patterning and between spatial patterning and community reassembly. Using mathematical models of water-limited plant communities, I will show that incorporating phenotypic plasticity into vegetation pattern-formation theory can resolve two outstanding puzzles associated with the fascinating Namibian fairy circle phenomenon and describe a predicted buffering effect of spatial patterning on community composition along rainfall gradients. Possible implications of these results to ecosystem functioning in stressed environments will be discussed.