Diversity patterns of wild bees in almond orchards and their surrounding landscape

Abstract

Insect pollination is essential for almond production, and most growers rely exclusively on honeybees for pollination. However, the number of honeybee hives has declined drastically over the last few decades and their efficiency in pollinating almond might be limited. Wild bee communities inhabiting the habitats surrounding almond orchards may provide significant pollination services to almond, but this has yet to be studied. In this preliminary investigation, we looked at spatial diversity patterns of wild bees in almond orchards and their surrounding landscape. The study was conducted in the Judean Foothills, a region with a Mediterranean ecosystem in central Israel, during almond bloom in 2008. We sampled bees and blooming plants in natural habitats, almond orchards, a weedy orchard (where wild flowers had been allowed to grow), and the margin between orchard and natural habitat. The margin and natural habitats had a significantly higher abundance of wild bees compared to the orchard, while the weedy orchard showed intermediate abundances. No significant differences were found among habitats in the number of wild bee genera, but there were significant differences in genera composition between the natural and orchard habitats. Honeybees were the main bee visitor to almond flowers. Nevertheless, the diverse and abundant wild bee community surrounding the orchards warrants further investigation of their role as almond pollinators.

Keywords:

• almond
• biodiversity conservation
• ecosystem service
• pollination
• wild bee