Autor/a:
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Aguilera, Guillermo; Roslin, Tomas; Miller, Kirsten; Tamburini, Giovanni; Birkhofer, Klaus; Caballero-López, Berta; Lindström, Sandra Ann-Marie; Öckinger, Erik; Rundlöf, Maj; Rusch, Adrien; Smith, Henrik G.; Bommarco, Riccardo
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Abstract:
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1. In agricultural landscapes, arthropods provide essential ecosystem services such
as biological pest control and pollination. Intensified crop management practices
and homogenization of landscapes have led to declines among such organisms.
Semi-natural habitats, associated with high numbers of these organisms, are increasingly lost from agricultural landscapes but diversification by increasing crop
diversity has been proposed as a way to reverse observed arthropod declines
and thus restore ecosystem services. However, whether or not an increase in the
diversity of crop types within a landscape promotes diversity and abundances
of pollinating and predaceous arthropods, and how semi-natural habitats might
modify this relationship, are not well understood.
2. To test how crop diversity and the proportion of semi-natural habitats within a
landscape are related to the diversity and abundance of beneficial arthropod communities, we collected primary data from seven studies focusing on natural enemies (carabids and spiders) and pollinators (bees and hoverflies) from 154 crop
fields in Southern Sweden between 2007 and 2017.
3. Crop diversity within a 1-km radius around each field was positively related to
the Shannon diversity index of carabid and pollinator communities in landscapes
rich in semi-natural habitats. Abundances were mainly affected by the proportion
of semi-natural habitats in the landscape, with decreasing carabid and increasing pollinator numbers as the proportion of this habitat type increased. Spiders
showed no response to either crop diversity or the proportion of semi-natural
habitats.
Synthesis and applications. We show that the joint effort of preserving semi-natural
habitats and promoting crop diversity in agricultural landscapes is necessary to
enhance communities of natural enemies and pollinators. Our results suggest
that increasing the diversity of crop types can contribute to the conservation of
service-providing arthropod communities, particularly if the diversification of
crops targets complex landscapes with a high proportion of semi-natural habitats.
KEYWORDS
agricultural intensification, arable land, crop diversity, diversification, ecosystem services,
landscape composition, pollination, predation |