Monday, August 6, 2007: 1:30 PM-5:00 PM
A2&7, San Jose McEnery Convention Center
SYMP 2 - Tipping points in the biosphere: Agriculture, water, and resilience
Land-use change due to agriculture has often been considered a local issue, but it is now one of the main driving forces of global environmental change. Ecosystem changes are being driven by demand for food and fiber for the world’s growing population, and our attempts to increase agricultural production have indirect effects that may lead to critical tipping points in global system properties.

Rapid, global intensification and extensification of agriculture are being driven by shifts to more meat-heavy diets, increasing trade in agricultural products, growing demand for biofuels, and a growing human population. Efforts to increase agricultural production often focus on production to the exclusion of other ecosystem functions important in sustaining wildlife habitat, high quality water supplies, and places to recreate. Ecosystem resilience may be diminished as a result, increasing the likelihood of crossing “tipping points”. Tipping points are thresholds beyond which the past response of the system no longer predicts the future; they are often triggered by positive feedbacks which can cause a shift to a new regime of system regulation. Crossing tipping points can produce sudden and large shifts in the supply of ecosystem services. In this session we focus on agriculture- and water-mediated tipping points. Examples include eutrophication of freshwater and estuarine systems through fertilizer runoff, salinization from irrigation, and changes in climate caused by alterations of water flows between land and atmosphere. While such tipping points have been studied and monitored at small scales, there have been few synthetic attempts to understand and model large-scale regime shifts. Such understanding is necessary to develop agricultural and development policies that sustain rather than degrade the biosphere.

In this session, we identify potential ‘tipping points’ or regime shifts, related to water and agriculture, that could have major consequences for the future of ecosystem services globally. We present new research assessing potential tipping points, and discuss new methods to detect, assess, and avoid undesired regime shifts.

Organizer:Elena Bennett, McGill University
Co-organizers:Garry Peterson, McGill University
Line Gordon, Stockholm University and Stockholm Environment Institute
Moderator:Garry Peterson, McGill University
1:30 PMTipping points in the earth system: Surprise, resilience, and governance
Garry Peterson, McGill University
1:40 PMPlanet under stress: Why understanding tipping points in the earth system is important
Lance Gunderson, n/a
2:00 PMHuman modification of green water flows: Influencing tipping points in ecosystems
Line Gordon, Stockholm University and Stockholm Environment Institute
2:20 PMSimulating changes in land-atmosphere interactions from agricultural expansion and irrigation in India: Potential impacts on the Indian Monsoon
Ellen Marie Douglas, University of Massachussetts - Boston, Dev Niyogi, Purdue University, Adriana Beltrán-Przekurat, University of Colorado, Roger A. Pielke Sr., University of Colorado
2:40 PMFeedbacks between agriculture and climate: An illustration of the potential unintended consequences of human land-use activities
Navin Ramankutty, McGill University, Christine Delire, Université Montpellier II, Peter Snyder, University of Illinois
3:00 PMBreak
3:10 PMMicroscale to macroscale feedbacks between vegetation and water
Max Rietkerk, Utrecht University, Stefan C. Dekker, Utrecht University, Marc F.P. Bierkens, Utrecht University
3:30 PMTipping points in rangelands: The scales of social-biophysical interactions
Brandon T. Bestelmeyer, USDA-ARS Jornada Experimental Range, Rhonda K. Skaggs, New Mexico State University, Debra P. Peters, USDA-ARS Jornada Experimental Range, Kris M. Havstad, USDA-ARS Jornada Experimental Range
3:50 PMAgricultural land use and climate change: Tipping points along the nitrogen cascade?
Simon Donner, Princeton University
4:10 PMHow can we incorporate resilience and tipping points into management of agriculture and water systems?
Johan Rockstrom, Stockholm Environment Institute, Elena M. Bennett, McGill University, Garry D. Peterson, McGill University, Line Gordon, Stockholm University and Stockholm Environment Institute
4:30 PMConcluding remarks: Finding surrogates to understand resilience in relation to tipping points
Elena Bennett, McGill University
4:40 PMPanel Discussion

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See more of The ESA/SER Joint Meeting (August 5 -- August 10, 2007)