Socio-economic Causes and Consequences of Future Environmental Changes Workshop a Workshop Sponsored by the U.s. Environmental Protection Agency’s National Center for Environmental Economics (ncee), National Center for Environmental Research (ncer)

Land-use change has received less attention than other threats to natural systems and in particular, exurban development is poorly understood despite the fact that it is the fastest growing type of land use in the United States. In this study, land use and cover information was integrated with watershed variables at two different scales resulting in new insights regarding the importance of addressing the environmental impacts of exurban development. The results from a coarse scale examination of the relationship between land cover and in stream habitat demonstrate that the proportion of agriculture and urban development at a watershed scale can be useful for predicting downstream embeddedness (amount of fine sediment in fish spawning gravels). Findings from our study indicate, for the first time, that urban and exurban development patterns have differential impacts on streams, suggesting that it is no longer appropriate to aggregate these land use types in risk assessment and forecast models. Improved parcel-level land use change models were used to estimate the expected changes to land cover due to land use change and how these changes may impact future stream conditions. This approach provides thresholds of different types of land use change beyond which stream habitat is likely to be impacted from increased sediment, which in turn can influence anadromous fish population recovery.