Environmental Studies Welcomes
Dr. Steve Carpenter
16 Nov 2009, 4 pm, RNS 150
Steve Carpenter, Director, Center for Limnology, University of Wisconsin-Madison, "Early Warnings of Big Changes in Ecosystems"
Abstract: Many important changes in ecosystems involve regime shifts in which an ecosystem crosses a critical threshold. Examples are collapse of exploited populations of fish or wildlife, eutrophication, epidemics, colonization by invasive species, desertification, conversion of rangeland to shrubland and many others. Ecological thresholds are sometimes difficult to measure, and consequently the precise location of ecological thresholds is highly uncertain. In management, crossings of ecological thresholds often come as surprises. If a critical threshold is approached gradually, however, there are early warnings of the impending regime shift. The status of research on early warning indicators, and their strengths and weaknesses, will be discussed.
Background reading:
Scheffer, M., J. Bascompte, W.A. Brock, V. Brovkin, S.R. Carpenter, V. Dakos, H. Held, E.H. Van Nes, M. Rietkerk and J. Sugihara. 2009. Early warning signals for critical transitions. Nature 461: 53-59.
Press release with a non-technical explanation and links to many examples:
http://www.sciencedaily.com/releases/2009/09/090902133625.htm
17 Nov 2009, 7 pm, RNS 150
Steve Carpenter, Director, Center for Limnology, University of Wisconsin-Madison, "Transformation of Global Ecosystem Services"
Abstract: Ecosystem services – the benefits that humans receive from nature – have changed more in the past 50 years than ever before in the history of our species. About two-thirds of ecosystem services are degrading globally. Among these deteriorating services are the processes that maintain air quality and climate, freshwater supplies, and soil fertility. Most projections indicate that drivers of degradation will intensify until at least mid-century. Scenarios for navigating this crisis fall into three general classes – (1) economic development with reinvestment in natural capital, (2) accelerated technological innovation and (3) emphasis on local adaptation. Pros and cons of these approaches will be reviewed and prospects for processes that draw on the best of all three scenarios will be discussed.
Background reading:
Carpenter, S. R., E. M. Bennett, and G. D. Peterson. 2006. Scenarios for ecosystem services: an overview. Ecology and Society 11(1): 29. [online] URL: http://www.ecologyandsociety.org/vol11/iss1/art29/
Some readable and accurate blog posts about the Millenium Ecosystem Assessment scenarios:
http://www.worldchanging.com/archives/002447.html
http://www.greenfacts.org/en/ecosystems/toolboxes/ma-scenarios.htm
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