Wild pollinators improve production, uniformity, and timing of blueberry crops

Animal pollination is an important input to the global food system, affecting 2/3 of crops and worth more than $100 billion annually. Mounting evidence of pollinators' importance, and of their decline worldwide, has prompted efforts to conserve and restore wild bees within agricultural regions. To date, however, research on the value of wild pollinators has focused largely on crop productivity per se and on intensely managed landscapes. Here, we combine field experiments, bee observations, and economic methods to estimate the impact of wild pollinators on the quantity and quality of blueberry crops within a low intensity agricultural landscape in Vermont, USA. Visits by wild bees reduced pollination limitation and increased seed set by up to 92%, fruit mass 12%, and fruit set 12%. Visitation also increased the uniformity of fruit size by up to 11% and advanced the timing of harvest by 2.5 days, both of which can increase crop value. For five out of six groups of wild bees, increased visits improved seed set relative to hand-pollinated controls. The potential economic value of relieving pollen limitation (and therefore improving fruit set and fruit mass) varied widely among farms. On most, production could increase 1-6% (representing $500-$4000 per year in additional revenue), but the maximum increase was 36% (representing $137,000 per year). Conserving wild pollinator communities, therefore, can increase crop quantity, quality, and farm revenue, but some farmers will benefit more than others. Farm-specific studies and recommendations are needed to best inform local and regional management decisions.