Proceedings of the National Academy of Sciences of the United States of America

About the PNAS Member Editor
Name Harrison, Susan P.
Location University of California, Davis
Primary Field Environmental Sciences and Ecology
 Election Citation
Harrison is a leader in the study of ecological diversity at different spatial and temporal scales, and of the mechanisms and processes that maintain diversity. Her work is of fundamental importance for understanding the impact of global change on ecological communities, and for conservation biology from local to global scales.
 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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