Growing food and fiber entails the use of fertilizer and irrigation systems and results in land clearing. These side effects of agriculture can lead to regime shiftsor tipping points which include desertification, salinisation, water degradation, and changes in climate due to altered water flows from land to atmosphere. As human populations shift to more meat-heavy diets, trade of agricultural products increases, and demand for biofuels grows, the pressure on agricultural systems is mounting. The challenge is to figure out how to meet these demands and keep the ecosystem functions that underpin productivity working. So say researchers who will participate in a symposium, Tipping points in the biosphere: Agriculture, water, and resilience during the Ecological Society of Americas Annual Meeting.
Tipping points occur when an ecosystem is overwhelmed by the demands placed on it and can no longer function the way it did before. In other words, it loses its resiliency which ultimately can lead to land that is rendered useless for growing crops.
Elena Bennett (McGill University), organizer of the symposium, says that we need to better understand large scale regime shifts in order to develop policies that sustain, rather than degrade, the very systems upon which humanity depends.
One of the reasons agricultural landscapes are so prone to regime shifts is that our management of them has tended to focus exclusively on improving one type of ecosystem service (e.g. food production, fiber production, biofuels production) at the cost of all others, explains Bennett.
She notes that agriculture is now one of the main driving forces of global environmental change. Bennett and other presenters in this session have identified potential tipping points related to water and agriculture that could have major global consequences.
No human activity has so large an impact on water systems as does agriculture, according to Johan R
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Contact: Nadine Lymn
nadine@esa.org
Ecological Society of America
6-Aug-2007