Seminar Abstract

Wednesday, July 09, 2008 • 12:15 PM • Medium Conference Room, SFI

Ehud Meron Ben Gurion University of the Negev, Isreal

Patterns of Biomass, Resource and Species Diversity in Dryland Vegetation

Landscapes of water-limited systems are mosaics of patches that differ in resource concentration, biomass production and species richness. Two processes affecting their structure and dynamics have attracted considerable attention during the past decade, self-organized patchiness and interspecific facilitation. Self-organized patchiness is a pattern formation phenomenon whereby positive water-biomass feedbacks at the level of a single patch result in vegetation patterns at the landscape level. A striking example of this phenomenon is banded vegetation on hill-slopes. Interspecific facilitation is a phenomenon whereby one species facilitates the growth of other species, by ameliorating their micro-environments. Facilitation often emerges when an environmental stress develops. Shrubs facilitating the growth of annuals in arid regions is a well studied example. In this talk I will present a platform of mathematical models for dryland plant communities, capable of upscaling plant-level attributes to species assemblage properties, and patch level interactions to landscape patterns and dynamics. I will further describe applications of this platform to studies of vegetation pattern formation, transitions from interspecific competition to facilitation along a rainfall gradient or as a result of spatial patterning, and species diversity along rainfall and consumer-pressure gradients. Theoretical results predicted by the models will be compared with aerial photographs and experimental data.

Host: Jennifer Dunne