A Multiscale Approach to the Study of Biotic Response to Climate Change

EPA Grant Number: U915979
Title: A Multiscale Approach to the Study of Biotic Response to Climate Change
Investigators: O'Keefe, Kim B.
Institution: Stanford University
EPA Project Officer: Michaud, Jayne
Project Period: January 1, 2001 through January 1, 2004
Project Amount: $102,000
RFA: STAR Graduate Fellowships (2001) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Climate Change , Global Climate Change


Climatic change affects communities and populations through changes in the physiology and behavior of individuals. Our ability to predict the effects of global warming on biotic communities ultimately depends on our understanding of how individual organisms cope with and respond to environmental stresses at multiple scales. There are several ways in which organisms can respond to changes in climatic conditions, ranging from shifts in species distribution to in situ evolution. However, for many species, particularly those that have low dispersal ability, adjustments in life history may be the first-order response to a changing environment. Understanding this first-order response is key to understanding how many populations will respond to climate change more broadly. I hypothesize that the environmental pressures that define a local habitat, in conjunction with the energetic demands of the individuals in that environment, are what drives intraspecific differences in life history and ultimately species response to a changing environment. The objective of this research project is to gain insight into the mechanistic processes that govern biotic response to climate change by characterizing the effects of climate and individual energetics on ground squirrels at multiple scales (geographic, temporal, and biologic).


I assess how microclimate influences life history strategies and what implications those differences in life history have on the local population dynamics of three populations of Spermophilus armatus existing across the elevational range of the species. I investigate the current genetics of these populations and assess whether differences in life history between these populations has a genetic basis. I explore genetic response to the climatic changes of the late Holocene by contrasting the patterns of modern and ancient genetic variation. Finally, I ascertain the role of individual energetics in shaping the species response to climate by applying a biophysical model based on first principles of energetics, and test whether this model accurately describes the patterns of life history variation, population dynamics, and past and present distributions of S. armatus. The results from this research project will provide a mechanistic link to biotic response to climatic change across many spatiotemporal scales, thus yielding predictive value to climatic-change models and improving our understanding of the ultimate impact of climate change on animal populations over time.

Supplemental Keywords:

fellowship, climate change, biotic response, global warming, Spermophilus armatus, population dynamics, life history variation, climatic-change models, ground squirrels., RFA, Scientific Discipline, Air, Hydrology, climate change, Air Pollution Effects, Economics, Atmosphere, ecosystem models, environmental monitoring, biodiversity, gateway communities, ground squirrels, terrestrial ecosystems, economic models, water quality, biotic response, aquatic ecology, landscape characterization, land use

Progress and Final Reports:

  • 2001
  • 2002
  • Final