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Wild bees, which are important for commercial pollination, depend on
floral and nesting resources both at farms and in the surrounding
landscape. Mass-flowering crops are only in bloom for a few weeks and
unable to support bee populations that persist throughout the year. Farm
fields and orchards that flower in succession potentially can extend the
availability of floral resources for pollinators. However, it is unclear
whether the same bee species or genera will forage from one crop to the
next, which bees specialize on particular crops, and to what degree
inter-crop visitation patterns will be mediated by landscape context. We
therefore studied local- and landscape-level drivers of bee diversity and
species turnover in apple orchards, blueberry fields and raspberry fields
that bloom sequentially in southern Quebec, Canada. Despite the presence
of high bee species turnover, orchards and small fruit fields complemented
each other phenologically by supporting two bee genera essential to their
pollination: mining bees (Andrena spp.) and bumble bees (Bombus spp.). A
number of bee species specialized on apple, blueberry or raspberry
blossoms, suggesting that all three crops could be used to promote
regional bee diversity. Bee diversity (rarefied richness, wild bee
abundance) was highest across crops in landscapes containing hedgerows,
meadows and suburban areas that provide ancillary nesting and floral
resources throughout the spring and summer. Promoting phenological
complementarity in floral resources at the farmstead and landscape scales
is essential to sustaining diverse wild bee populations.
252 views reported since publication in 2018.