Effects of native biodiversity on grape loss of four castes: testing the biotic resistance hypothesis

摘要: Abstract. Management of agricultural landscapes can influence the biodiversity and ecological services provided by these ecosystems, such as natural biological pest control. Viticulture is a very important economic activity in most countries with Mediterranean climate, often shaping their culture. Grape production affected number pests diseases, farmers use prophylactic response-driven pesticides to control pests. Here we quantified main biotic causes crop losses four grape castes, two red (Touriga Nacional Baga) white (Arinto Chardonnay), evaluated potential effect native provide resistance outbreaks losses. Specifically, diversity abundance bird insect communities vineyards were divided into functional guilds (pest, neutral or auxiliary), test whether hold naturally (biotic hypothesis) under normal vineyard management (including pesticide application regimes). A association between distance edge was also evaluated. We recorded small proportion (mean  =  0.6 %; max  =  7.5 %), showing preference for castes Baga (red) Chardonnay (white), while avoided caste Arinto (white). color did not caused pests, but birds showed castes. The more vulnerable fungi. Despite low impact on production, insects detected six which entails potentially level this highly managed ecosystem. Further research necessary fully evaluate role vineyards, particularly if alternative processes, organic farming, increase protect against from lower regimes chemical spraying.