NERC Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom.
Ecol Appl. 2011 Jul;21(5):1760-71. doi: 10.1890/10-0677.1.
The global decline of insect pollinators, especially bees, is cause for concern, and there is an urgent need for cost-effective conservation measures in agricultural landscapes. While landscape context and habitat quality are known to influence species richness and abundance of bees, there is a lack of evidence from manipulative field experiments on bees' responses to adaptive management across differently structured landscapes. We present the results of a large-scale study that investigated the effects of a targeted agri-environment scheme (AES) on bumble bees (Bombus spp.) over three years in the United Kingdom. Forage patches of different sizes were sown with a conservation flower mixture across eight sites covering a broad range of agricultural land use types. Species richness and worker densities (especially of the longer-tongued Bombus species for which the mixture was targeted) were significantly higher on sown forage patches than on existing non-crop control habitats throughout the three-year study, but the strength of this response depended on both the proportions of arable land and abundance of herbaceous forb species in the surrounding landscape. The size of sown patches also affected worker density, with smaller patches (0.25 ha) attracting higher densities of some species than larger patches (1.0 ha). Our models show that a targeted AES can deliver greater net benefits in more intensively farmed areas, in terms of the number and species richness of bumble bees supported, than in heterogeneous landscapes where other foraging habitats exist. These findings serve to strengthen the evidence base for extending agri-environment schemes to boost declining pollinator populations to a larger number of agricultural landscapes across the globe.
全球昆虫传粉媒介（尤其是蜜蜂）的减少令人担忧，因此迫切需要在农业景观中采取具有成本效益的保护措施。虽然景观背景和生境质量已知会影响蜜蜂的物种丰富度和数量，但在不同结构的景观中，针对蜜蜂对适应性管理的反应进行的操纵性田间实验证据不足。我们提出了一项大规模研究的结果，该研究调查了三年内在英国实施的有针对性的农业环境计划（AES）对大黄蜂（Bombus spp.）的影响。在八个地点，不同大小的饲料斑块播种了保护性花卉混合物，这些地点涵盖了广泛的农业土地利用类型。在整个三年的研究中，与现有的非作物对照生境相比，播种饲料斑块的物种丰富度和工蜂密度（尤其是针对该混合物的长舌大黄蜂物种）显着更高，但这种反应的强度取决于周围景观中可耕地的比例和草本植物的丰度。播种斑块的大小也影响了工蜂密度，较小的斑块（0.25 公顷）比较大的斑块（1.0 公顷）吸引了更多某些物种的工蜂。我们的模型表明，与在存在其他觅食生境的异质景观中相比，有针对性的 AES 可以在更集约的农业地区带来更大的净效益，就支持的大黄蜂数量和物种丰富度而言。这些发现为扩大农业环境计划以促进全球更多农业景观中下降的传粉媒介种群提供了更有力的证据。
