What is the Best Urbanization or Conservation Strategy?

Dave Levitan, writing for Conservation Magazine: Conservation this Week:

Scorpions and Centaurs; Flickr

Scorpions and Centaurs; Flickr

Cities are going to get bigger. With more than half the world now living in urban areas, and that percentage growing steadily, that means the concrete and steel will have to stretch out into areas that are currently forest and farm and grass. But just letting that process happen without a plan is likely to be a very bad idea.

A study published in the journal Landscape and Urban Planning simulated the urbanization process in the Piedmont region of North Carolina out to 2032. The question the authors posed was, essentially, what land will suffer in favor of the ever-growing city?

“The application of conservation planning scenarios in land change modeling is often implemented by simply treating priority areas as protected, essentially removing them from eligibility for development,” the authors wrote. “However, full protection of all priority resources is highly unlikely in urbanizing areas.” By understanding what types of policies are likely to result in the best use of land, that type of failed prohibition might be avoided.
Monica A. Dorning, Jennifer Koch, Douglas A. Shoemaker, and Ross K. Meentemeyer

Land that is of great value for conservation can also be highly suitable for human use, resulting in competition between urban development and the protection of natural resources. To assess the effectiveness of proposed regional land conservation strategies in the context of rapid urbanization, we measured the impacts of simulated development patterns on two distinct conservation goals: protecting priority natural resources and limiting landscape fragmentation. Using a stochastic, patch-based land change model (FUTURES) we projected urbanization in the North Carolina Piedmont according to status quo trends and several conservation-planning strategies, including constraints on the spatial distribution of development, encouraging infill, and increasing development density. This approach allows simulation of population-driven land consumption without excluding the possibility of development, even in areas of high conservation value. We found that if current trends continue, new development will consume 11% of priority resource lands, 21% of forested land, and 14% of farmlands regionally by 2032. We also found that no single conservation strategy was optimal for achieving both conservation goals. For example, strategies that excluded development from priority areas caused increased fragmentation of forests and farmlands, while infill strategies increased loss of priority resources proximal to urban areas. Exploration of these land change scenarios not only confirmed that a failure to act is likely to result in irreconcilable losses to a conservation network, but that all conservation plans are not equivalent in effect, highlighting the importance of analyzing tradeoffs between alternative conservation planning approaches.