Submitted to: Conservation Biology
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2006
Publication Date: 6/29/2006
Citation: Greenleaf, S., Baumgartner, K. 2006. Intact natural habitat protects vineyards from lethal pierce's disease in napa, ca. Conservation Biology.
Technical Abstract: Research on vectored crop diseases has focused on the disease triangle, which is limited to three species and the interactions among them: the crop plant, pathogen, and vector. Failing to consider the ecosystem and landscape context can lead to ineffective managment practices. For example, in Northern California, Pierce's disease of grapevines, which has caused substantial economic damage, is vectored by a native insect. Anecdotal reports reflect the belief that Pierce's disease occurs primarily near riparian habitat; consequently, growers are extirpating riparian vegetation and applying pesticides to riparian corridors, despite no evidence that these practices reduce disease incidence. We present a conceptual model of how the components of a mixed agricultural and wild landscape interact to affect disease incidence. We also present results from our landscape scale investigation of the spatial distribution of Pierce's disease. We found no Pierce's disease in vineyards situated in a landscape dominated by natural habitat. However, when vineyards were in a landscape dominated by both agricultural and urban habitats, Pierce's disease occurred; furthermore, in this landscape context, disease was most likely to occur in vineyards adjacent to riparian habitat. These results suggest that where large areas of natural habitat remain intact, vineyards are protected from disease but that when natural habitat becomes sufficiently reduced and fragmented Pierce's disease increases.