Mapping vineyard expansion provides information on agriculture and the environment

Vineyards are expanding rapidly in California's coastal counties due to a booming wine market. This change in land use has led to public debate over natural habitat removal, overproduction of wine grapes, loss of agricultural diversity, and changing scenery. Using a geographic information system (GIS) to map and analyze vineyard expansion in Sonoma County, approximately 11,600 acres of new vineyards were identified from 1990 through 1997. The total acreage was calculated to be at least 48,000 acres in 1997, 20% more than reported by county agricultural officials. Compared to vineyards established before 1990, a higher percentage of vineyards planted between 1990 and 1997 were located on hillsides that supported oak woodlands. Oak woodlands support a majority of the region's biodiversity, provide ecosystem goods and services, and have aesthetic value. This research was designed to document the effects of recent vineyard expansion on Sonoma County's hardwood rangelands and to provide tools for informed discussion and decision-making by land-use planners, farmers, residents and environmentalists