The influence of exurban landscapes and local site characteristics on riparian vegetation

The southern Appalachian Mountains have experienced large population growth and a change in land use in the past 30 years. The majority of development has been low density, suburban land, known as exurban development. The long-term effects of exurbanization on riparian vegetative communities in the southeastern Appalachian Mountains are not well known. We sought to determine if vegetative community composition and structure change as a function of watershed–level variables such as time since neighborhood development or percent impervious surface within the watershed. We also assessed local–scale measures of disturbance such as canopy cover and basal area. Over two years we sampled a total of 27 streams in exurban watersheds ranging in age from four to forty-four years, along with eight forested streams. Watershed–scale variables such as neighborhood age and impervious surface cover did not influence the aspects of riparian vegetation community we measured. Canopy cover, a measure of local habitat disturbance, offered better predictions of vegetation community metrics. Exurban neighborhoods and their landowners may have the potential to manage for riparian vegetation through the use of maintained stream buffer zones along the entire length of the stream.