Crop pollination services

Crop pollination by bees and other animals is an ecosystem service of enormous economic value (Losey andVaughan 2006; Allsopp et al. 2008). Pollination can increase the yield, quality, and stability of crops as diverse as almond, cacao, canola, coffee, sunflower, tomato and watermelon. Indeed, Klein et al. (in press) found that 75% of globally important crops benefit from animal pollination. The value of this service, while difficult to quantify properly, has been estimated several times over the past decade (Southwick and Southwick 1992; Costanza et al. 1997; Losey and Vaughan 2006; Allsopp et al. 2008) with a recent estimate of 195 billion Euros (-$200 billion) worldwide (Box 10.1). While much research and policy attention has focused on managed bees (especially the honey bee, Apis mellifera), wild bees and other insect species also contribute importantly to crop pollination. Our models focus on wild bees, because the pollination they deliver represents an ecosystem service from natural systems. In fact, for some crops (e.g., blueberry), wild bees are more efficient and effective pollinators than honey bees (Cane 1997). Diverse bee communities potentially provide more stable pollination services over time, compared to single (managed) species (Greenleaf and Kremen 2006; Hoehn et al .. 2008). Finally, if alarming regional declines in honeybee populations continue (National Research Council of the National Academies 2006; Stokstad 2007; Klein et al., in press), wild pollinators may become increasingly important to farmers.