Monday, August 3, 2009

PS 7-76: On the emergence of conservation behavior in a simple model of land-use with ecosystem services

Andres Baeza, University of Michigan, Mercedes Pascual, University of Michigan AND Howard Hughes Medical Institute, and Andy P. Dobson, Princeton University.

Background/Question/Methods

Ecosystem services are a key concept in conservation. They represent the connection between the ways in which ecosystem's function and human welfare; they lie at the interface between ecological and economical considerations. One important goal in the study of ecosystem services for decision management is to find functions that describe how ecological processes can be transformed into the benefits that humans receive from ecosystems. However this connection depends strongly on how humans interpret the benefits they receive from the environment, making human behavior central to transforming ecosystem services into conservation.

To examine the conditions for the emergence of a conservation strategy, we extended a previous model of land use change that incorporates ecosystem services and population growth (Dobson et al, 1998, 2008). Our new model is spatially explicit and follows the transition of land between different states including pristine forest, agriculture, degraded and abandoned land, and land populated by humans for agriculture and other explicit economic activities. The model further allows the human population to evolve conservation strategies that reflect the ways in which they value either the natural habitat, or the ecosystem services it supplies to agricultural lands. As humans migrate through the landscape they adopt and change the degree to which they conserve the natural resources on the pristine land. As more land transitions to agriculture, the human population increases but the productivity and lifespan of agriculture itself decreases as the forest area also diminishes.  

Results/Conclusions

Our initial results suggest that conservation strategies only evolve at the population level under relatively restricted condition; under most conditions humans adopt instead a fugitive strategy of ‘swidden agriculture’ that depletes the natural resource locally as they move through the landscape. Specific conditions that result in a conservation strategy include the consideration of not just the duration ,but also the quantity of the ecosystem service, and of a shape and strength of the functions that couple ecosystems services to natural ‘pristine’ habitats. The work suggests that the emergence of successful conservation strategies, depends significantly on both the functional form of the ecosystem services, the direct local benefit of the natural resource to humans, and how accurately humans perceive and quantify these connections.