Diversity and Abundance Comparisons Between Vineyard and Grazing Land Adjacent to Oak Woodland 1

Animal and plant species diversity, abundance, and distribution were examined across a landscape that included areas transformed from annual grass rangeland to agricultural production. Surveys were conducted quarterly over four years within an area recently placed in agricultural use and in undisturbed grassland. Here, we report results from bird and insect components of the surveys. Vineyard habitat and annual grassland habitat were compared with respect to statistical differences in species number, and population number. A higher diversity and abundance of survey organisms was found within the vineyard than in annual grassland habitat. Compared to undisturbed grassland the vineyard areas provide a more complex habitat supporting more species and larger populations of insects and birds. The study raises questions regarding the effect of vineyards on adjacent habitats, the value of vineyard habitats to species other than crop plants, and whether management protocols can prevent development of wildlife sinks within vineyards and orchards.