Jeff Price

Assistant Professor
Department of Geological and Environmental Sciences

Phone: 898-4748
Campus ZIP: 205
Building: HOLT, Room 313
e-mail: jtprice@csuchico.edu

Nonlinear dynamics in ecosystem response to climatic: Case studies and policy implications

For a pdf. file of the article, click here.

Excerpt from the Introduction
Since the first United Nations-sponsored assessment of climate change was published by the Intergovernmental Panel on Climate Change (IPCC, 1990), hundreds of reports and journal articles have described the past and potential impacts of climatic change on species and their habitats (Sagarin et al., 1999; Thomas and Lennon, 1999; Hossell et al., 2000; IPCC, 1996, 2001b; NAST, 2000; Australian Greenhouse Office, 2003; Root et al., 2003). Although these studies documented changes that are clearly related to climate trends, they also revealed many challenges in predicting the outcome on species and ecosystems. These difficulties are commonly attributed to the influence of non-climatic variables, variance among thresholds at which species respond to environmental factors, and complex interactions among responses to environmental change. Challenges in disentangling natural and cultural factors have further limited the scope of ecosystem impact assessments. The fact remains, however, that understanding the complexity of potential impacts of climate change on natural ecosystems is essential if resource managers are to minimize the negative consequences of climate change and maximize the potential benefits that it may offer.

Complex and nonlinear physical, chemical, and biological interactions are becoming an increasingly important focus for climate change impact assessments and basic research (Pielke et al., 2003). The International Geosphere–Biosphere Programme of the International Council for Science hosted a workshop on the topic of ‘‘Nonlinear Responses to Global Environmental Change’’ in 2001 and convened a working group in 2003 titled ‘‘Development of Earth SystemModels to Predict Nonlinear Responses/Switches’’. Reports from these meetings challenge scientists to identify manifestations of nonlinear behavior in the Earth’s physical, biological, and chemical systems so that strategies for adaptation will be expanded beyond the current focus on the proportional, linear responses to climate forcing (IGBP, 2003; Pielke et al., 2003).