Early warning of discontinuous changes in ecosystem state: Myth, reality, or somewhere in between?

• Kathryn L. Cottingham

Activity	Dates	Further Information
Postdoctoral Fellow	1st August 1996—1st September 1998	Participant List

Abstract

Humans depend on ecological systems for a variety of services. These services are threatened by anthropogenic perturbations that may cause sudden, discontinuous changes in ecosystem state. Consequently, management and regulatory agencies have invested a great deal of effort in developing early warning indicators for these discontinuous changes. However, the theoretical and empirical basis for such indicators is not well developed. I propose to use simulation modeling and literature analysis to test the hypothesis that reliable early warning indicators of discontinuous change do not exist. If affirmed, this hypothesis suggests that the effects of increasing human impacts on ecosystems may not be reliably anticipated. If rejected, this hypothesis suggests that a sound basis for environmental indicators can be developed. Regardless of the outcome, this research will expand our understanding of ecosystem response to anthropogenic perturbations.

Type	Products of NCEAS Research
Report or White Paper	Cottingham, Kathryn L. 1997. Parallel responses to whole-lake experiments: evidence for multiple attractors in zooplankton communities. (Online version)
Report or White Paper	Cottingham, Kathryn L. 1997. Report of progress and activities in prior appointment period. (Online version)
Journal Article	Cottingham, Kathryn L. 1998. Nutrients and zooplankton as multiple stressors of phytoplankton communities: Evidence from size structure. Limnology and Oceanography. Vol: 44. Pages 810-827.
Journal Article	Cottingham, Kathryn L.; Carpenter, Stephen R. 1998. Population, community, and ecosystem variates as ecological indicators: Phytoplankton responses to whole-lake enrichment. Ecological Applications. Vol: 8(2). Pages 508-530.
Report or White Paper	Cottingham, Kathryn L. 1998. Report of progress and activities in appointment period: Sept. 1997 - July 1998. (Online version)
Journal Article	Cottingham, Kathryn L.; Carpenter, Stephen R.; St. Amand, A. 1998. Responses of epilimnetic phytoplankton to experimental nutrient enrichment in three small seepage lakes. Journal of Plankton Research. Vol: 20. Pages 1889-1914.
Journal Article	Cottingham, Kathryn L.; Schindler, Daniel E. 2000. Effects of grazer community structure on phytoplankton response to nutrient pulses. Ecology. Vol: 81. Pages 183-200.
Journal Article	Cottingham, Kathryn L.; Rusak, James A.; Leavitt, Peter R. 2000. Increased ecosystem variability and reduced predictability following fertilisation: Evidence from palaeolimnology. Ecology Letters. Vol: 3. Pages 340-348.
Journal Article	Cottingham, Kathryn L. 2002. Tackling biocomplexity: The role of people, tools, and scale. BioScience. Vol: 52(9). Pages 793-799.
Journal Article	Gram, Wendy K.; Borer, Elizabeth T.; Cottingham, Kathryn L.; Seabloom, Eric; Boucher, V.; Goldwasser, Lloyd; Micheli, Fiorenza; Kendall, Bruce E.; Burton, Rebecca S. 2004. Distribution of plants in a California serpentine grassland: Are rocky hummocks spatial refuges for native species?. Plant Ecology. Vol: 172. Pages 159-171.
Journal Article	Jackson, Leland J.; Trebitz, Anett S.; Cottingham, Kathryn L. 2000. An introduction to the practice of ecological modeling. BioScience. Vol: 50(8). Pages 694-706.
Journal Article	Micheli, Fiorenza; Cottingham, Kathryn L.; Bascompte, Jordi; Bjornstad, Ottar N.; Eckert, Ginny; Fischer, Janet; Keitt, Timothy H.; Kendall, Bruce E.; Klug, Jen; Rusak, James A. 1999. The dual nature of community variability. Oikos. Vol: 85. Pages 161-169.
Journal Article	Rusak, James A.; Yan, Norman; Somers, K.; Cottingham, Kathryn L.; Micheli, Fiorenza; Carpenter, Stephen R.; Frost, Thomas M.; Paterson, Michael; McQueen, D. 2002. Temporal, spatial, and taxonomic patterns of crustacean zooplankton variability in unmanipulated north-temperate lakes. Limnology and Oceanography. Vol: 47. Pages 613-625.
Journal Article	Seabloom, Eric; Borer, Elizabeth T.; Boucher, V.; Burton, Rebecca S.; Cottingham, Kathryn L.; Goldwasser, Lloyd; Gram, Wendy K.; Kendall, Bruce E.; Micheli, Fiorenza. 2003. Competition, seed limitation, disturbance, and reestablishment of California native annual forbs. Ecological Applications. Vol: 13(3). Pages 575-592.