Through a detailed analysis of the science, policy and design of land use, researchers at the University of Michigan are examining how "exurban" areas outside of American's urban and suburban areas can absorb more carbon from the atmosphere.

The research could lead to changes in how developers, residents and even local planning boards think about land-cover management, the value of land and land-use policies. Ultimately, those discussions could lead to local decisions and rules, zoning policies, educational initiatives, and design innovations that promote patterns of development and landscape design that increase absorption of carbon, which could slow climate change.

"Exurban residential development is widespread and constitutes one of the major forms of land-use and land-cover changes in the eastern U.S. and elsewhere," said Dan Brown, the project's lead researcher and a professor at U-M's School of Natural Resources and Environment. "This sprawl has large impacts on vast landscapes, ecosystem services and quality of life of millions of people."

Exurban areas are often defined as low-density residential developments that exist beyond traditional urban and suburban areas, and which are often disconnected from urban services like sewer and water.

The National Science Foundation is funding the research with a $1.5 million award. This project's research goals are to investigate the process of carbon absorption in the vegetation of exurban residential areas; the preferences of residents for land-cover types and patterns in those areas; and land-management activities of residents and developers.

Researchers want to produce a clearer understanding of the relationships among carbon dynamics, land-management activities and market and non-market values of land-uses, and land-covers - with a focus on how carbon dynamics might respond to various management and policy options for land-cover management.

They will use aerial-photo interpretation, field studies and ecosystem-process modeling that will simulate plant-soil feedbacks and soil-carbon storage as well as allow simulation of landowner management of vegetation and detritus. Surveys and social simulations will be used to understand how large-scale landscape patterns emerge from decisions by individual developers and landowners over time, and will be linked to social survey data.

The results of this computational social-simulation model will be used to understand how the factors that influence decisions of individual developers and landowners ultimately drive land-use change, and how these interactions through the land market influence large-scale patterns of land value.

Other SNRE researchers involved in the project are Joan Nassauer, a professor of landscape architecture, and Bill Currie, an associate professor of terrestrial ecosystems.í‚   Also involved are researchers from U-M's Center for the Study of Complex Systems and George Mason University's Department of Computational Social Science.

"The specific ecosystem service we are focused on is carbon storage," Brown said. "The problem is that existing scientific literature hasn't dealt well with these í¢â‚¬Ëœin-between' landscapes - that aren't really urban or rural. So we don't know enough about how they work in terms of ecological process and people's perceptions and behaviors."

"As a result, the project hopes to improve understanding rather than necessarily produce immediate impacts for use by a local zoning commission, for example," Brown added. "We expect that the research will get people thinking differently. We want developers, residents and policymakers to begin to view exurban areas as ecosystems and to think about policies and incentives that would improve the services they provide."

The research examines data collected in southeastern Michigan, but the findings will be applicable to similar exurban regions across the country, Brown said. Southeastern Michigan will thus be used as a model system to study processes controlling carbon storage over much larger regions.í‚   Data collection will range from surveys of residential preferences that drive land cover change and residential practices such as planting, mowing, and burning, to intensive field studies of soil and vegetation carbon storage, to interpretation of aerial photography and analysis of census data and satellite imagery.í‚  í‚  í‚  

Exurban residential development is an increasingly critical determinant of landscape patterns at the urban and rural fringes throughout the United States. Because of the increasingly large areas defined by these trends, exurban locations are implicated in the carbon dynamics of North America. This important phenomenon has human and natural components while reflecting changes in the way people perceive and use landscapes.

Changes in soils and vegetation associated with exurban development could reasonably be expected to produce either a landscape-scale source or sink (absorber) of carbon to or from the atmosphere. But whether that happens or not depends on the nature of the development. As a result, an opportunity exists to discover how exurban land management and policies might be directed to help keep human-dominated exurban landscapes on the sink side of this balance; to provide an essential ecosystem service; and help mitigate the worst effects of climate change.

In order to seize that opportunity, however, researchers need to provide policy makers with new understanding and intellectual integration of the complex interactions involved, as well as tools, such as computer models, to forecast and evaluate policy implications. Providing this type of integration is the hallmark of research at SNRE.í‚   One of the steps in this project will be to develop new computer modeling approaches that can be applied to address this new and growing set of research questions.

A major gap in current understanding exists in the relationship between exurban development and the resulting effects on the landscape-carbon balance. Increases in productivity across the Northern Hemisphere, at least partially driven by exurban land-use change, have important implications for the balance of carbon globally and thus for efforts to manage landscape-carbon balance to mitigate climate change.

Resident behaviors affect the carbon cycle in several ways, too. Increased open space and mature vegetation generally increase values of residential properties. Meanwhile, new residents bring landscaping management behaviors that may reinforce or degrade the path of carbon sequestration on the newly converted and occupied property. While landowners may not think of their activities as "management", their actions in mowing, mulching, and watering lawns, as well as planting and pruning trees and burning branches and logs, when scaled up to the region, have a dramatic effect on the balance of carbon transferred between the landscape and the atmosphere.

"It will not be possible to understand the drivers of carbon cycling in fragmented, exurban landscapes without linking these causally to human drivers of land-use patterns," Brown said. "As importantly, because natural amenities, open space and other land-based natural resources affect exurban land-use decision making, land-use-change processes contain feedbacks such that changes to land-cover made by one set of actors alter the subsequent social and economic values generated by the landscape, and the decisions of new actors."

About the School of Natural Resources and Environment
The School of Natural Resources and Environment's overarching objective is to contribute to the protection of the Earth's resources and the achievement of a sustainable society. Through research, teaching, and outreach, faculty, staff, and students are devoted to generating knowledge and developing policies, techniques and skills to help practitioners manage and conserve natural and environmental resources to meet the full range of human needs on a sustainable basis.
http://www.snre.umich.edu/

About the Center for the Study of Complex Systems
Established in 1999, í‚ ­í‚ ­the Center for the Study of Complex Systems is a broadly interdisciplinary program designed to encourage and facilitate research and education in the general area of nonlinear, dynamical and adaptive systems. Its more than 50 participating faculty represent nearly every college of the University. More than half of these take an active role in CSCS including participation in grant proposals, research groups and administration.
http://www.cscs.umich.edu/

 

More information on:
Professor Dan Brown: http://www.snre.umich.edu/profile/danbrown
Professor William Currie: http://www.snre.umich.edu/profile/wcurrie
Professor Joan Nassauer: http://www.snre.umich.edu/profile/nassauer