Susan Harrison is an ecologist known for her work on the dynamics of natural populations and the diversity of ecological communities. Early in her career she was mainly known for testing and revising theories about the influence of naturally fragmented habitats on population persistence and community dynamics. More recently she has become known for analysing how plant communities respond to natural climatic variation and recent climate change. She was born and raised in Sonoma, California. At UC Davis she received a bachelor?s degree in Zoology in 1983 and a Master’s degree in Ecology in 1986. At Stanford University she was awarded a PhD in Biology in 1989. She was a postdoctoral fellow at the Centre for Population Biology, Imperial College at Silwood Park from 1990-1991, following which she joined the faculty of Environmental Science and Policy at UC Davis in 1991. She is a Fellow of the California Academy of Sciences and a Fellow of the Ecological Society of America, and has been a Vice-President of the American Society of Naturalists.

Research Interests

Research in the Harrison lab seeks to understand the processes that shape and maintain plant species diversity at the landscape scale, where small-scale forces such as competition and facilitation interact with large-scale forces such as niche evolution and dispersal. Studying the highly diverse and endemic-rich Californian flora, they found that major patterns in diversity at the species, functional, and phylogenetic scales align with the region?s strong climatic gradients in a way that suggests an overriding influence for regional biogeographic history. In turn, diversity within local communities strongly reflects these larger-scale regional influences. Working in both northern Californian grasslands and southern Oregon forest understories, they found that plant community diversity has declined in response to the warmer and/or drier climate of recent decades, and that species with functional traits indicating drought-intolerance were especially likely to have been lost. However, these effects of climate on diversity appeared to be weaker in settings where nutrients rather than water are the most limiting resource, and where the physical environment selects for species with stress-tolerant functional traits.

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Primary Section

Section 63: Environmental Sciences and Ecology