Data for: Hedgerows have contrasting effects on pollinators and natural enemies and limited spillover effects on apple production

Agricultural intensification has resulted in a decline in insect
biodiversity and threatens the provision of valuable ecosystem services.
Agri-environment schemes (AESs) have been implemented in an effort to
conserve biodiversity on farmland and increase agricultural
sustainability, but their effectiveness can vary widely. To better
determine which factors influence AES effectiveness, the relative roles of
local habitat features, habitat quality, and landscape context need to be
further explored. The aim of this study was to determine the most
important factors influencing field margin AES effectiveness in commercial
apple orchards, in terms of arthropod biodiversity conservation and
ecosystem service provision. We surveyed wild bees and aphid natural
enemies in field margins and apple trees in 20 orchards, ten bordered by
hedgerow field margins (an AES) and ten with herbaceous field margins (no
hedgerows present, not an AES). We considered field margin floral
resources and the cover of semi-natural habitat in the surrounding
landscape as indicators of local habitat quality and landscape context,
respectively. We furthermore quantified pollination and pest control as
measures of ecosystem service delivery and the relationship between
arthropod communities and apple yield (initial and final fruit set) and
quality. We found that hedgerow presence strongly predicted both
pollinator and natural enemy communities and that these relationships were
more pronounced than those with local habitat quality and landscape
context. Hedgerows were negatively related to wild bee richness and
abundance within the orchard, and positively related to natural enemy
richness and abundance at the field margin but not within the orchard. We
found no relationships between local and landscape factors and ecosystem
service delivery, and no relationship between wild bee communities and
apple yield, suggesting that apple is not pollen limited in our study
system. There was, however, a negative relationship between natural enemy
richness and initial fruit set. We conclude that annually cut hedgerows
can benefit the conservation of natural enemies, but have limited
arthropod-mediated private benefits for apple production, and likely need
to be supplemented with additional local habitat resources for the
conservation of wild bees. Our findings indicate that local habitat
factors can strongly influence biodiversity regardless of landscape
context, but that AESs likely need to be designed with separate
biodiversity and ecosystem service targets, and specific taxonomic groups,
in mind.