Abstract

Ecological intensification provides opportunity to increase agricultural productivity while minimizing negative environmental impacts, by supporting ecosystem services such as crop pollination and biological pest control. For this we need to develop targeted management solutions that provide critical resources to service-providing organisms at the right time and place. We tested whether annual strips of early flowering phacelia Phacelia tanacetifolia support pollinators and natural enemies of seed weevils Protapion spp., by attracting and offering nectar and pollen before the crop flowers. This was expected to increase yield of red clover Trifolium pratense seed. We monitored insect pollinators, pests, natural enemies and seed yields in a total of 50 clover fields along a landscape heterogeneity gradient, over 2years and across two regions in southern Sweden. About half of the fields were sown with flower strips of 125-2,000m(2). The clover fields were pollinated by 60% bumble bees Bombus spp. and 40% honey bees Apis mellifera. The clover seed yield was negatively associated with weevil density, but was unrelated to bee species richness and density. Flower strips enhanced bumble bees species richness in the clover fields, with the strongest influence in heterogeneous landscapes. There were few detectable differences between crop fields with and without flower strips. However, long-tongued bumble bees were redistributed toward field interiors and during phacelia bloom honey bees toward field edges. Clover seed yield also increased with increasing size of the flower strip. We conclude that annual flower strips of early flower resources can support bumble bee species richness and, if sufficiently large, possibly also increase crop yields. However, clover seed yield was mainly limited by weevil infestation, which was not influenced by the annual flower strips. A future goal should be to design targeted measures for pest control.

Keywords

biological control; Bombus; ecological intensification; ecosystem services; floral resources; habitat enhancement; pollination; Protapion; red clover; Trifolium pratense

Published in

Ecology and Evolution
2018, Volume: 8, number: 16, pages: 7974-7985
Publisher: WILEY

SLU Authors

• Lundin, Ola

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Bommarco, Riccardo

  • Department of Ecology, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


Sustainable Development Goals

SDG15 Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss
SDG2 End hunger, achieve food security and improved nutrition and promote sustainable agriculture
SDG12 Ensure sustainable consumption and production patterns


UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1002/ece3.4330

Permanent link to this page (URI)

https://res.slu.se/id/publ/96717