Data from: Targeted agri-environment schemes significantly improve the population size of common farmland bumblebee species

Changes in agricultural practice across Europe and North America have been associated with range contractions and local extinction of bumblebees (Bombus spp.). A number of agri-environment schemes have been implemented to halt and reverse these declines, predominantly revolving around the provision of additional forage plants. Although it has been demonstrated that these schemes can attract substantial numbers of foraging bumblebees, it remains unclear to what extent they actually increase bumblebee populations. We used standardized transect walks and molecular techniques to compare the size of bumblebee populations between Higher Level Stewardship (HLS) farms implementing pollinator-friendly schemes and Entry Level Stewardship (ELS) control farms. Bumblebee abundance on the transect walks was significantly higher on HLS farms than ELS farms. Molecular analysis suggested maximum foraging ranges of 566 m for Bombus hortorum, 714 m for B. lapidarius, 363 m for B. pascuorum and 799 m for B. terrestris. Substantial differences in maximum foraging range were found within bumblebee species between farm types. Accounting for foraging range differences, B. hortorum (47 vs 13 nests/km2) and B. lapidarius (45 vs 22 nests/km2) were found to nest at significantly greater densities on HLS farms than ELS farms. There were no significant differences between farm type for B. terrestris (88 vs 38 nests/km2) and B. pascuorum (32 vs 39 nests/km2). Across all bumblebee species, HLS management had a significantly positive effect on bumblebee nest density. These results show that targeted agri-environment schemes that increase the availability of suitable forage can significantly increase the size of wild bumblebee populations.

欧洲及北美地区的农业生产方式变革，与熊蜂属（Bombus spp.）熊蜂的分布范围缩减及区域性灭绝密切相关。为遏制并扭转熊蜂种群的衰退趋势，多项农业环境计划（agri-environment schemes）已得以推行，此类计划的核心多围绕补充饲用植物资源展开。尽管已有研究证实，此类计划可吸引大量觅食的熊蜂，但目前仍不清楚它们在多大程度上可切实提升熊蜂种群规模。本研究采用标准化样带行走调查法与分子生物学技术，对比了实施授粉友好型计划的高级管理（Higher Level Stewardship, HLS）农场与作为对照的入门管理（Entry Level Stewardship, ELS）农场的熊蜂种群规模。样带调查结果显示，HLS农场内的熊蜂丰度显著高于ELS农场。分子分析表明，园林熊蜂（Bombus hortorum）的最大觅食距离为566米，红尾熊蜂（Bombus lapidarius，简称B. lapidarius）为714米，犬熊蜂（Bombus pascuorum，简称B. pascuorum）为363米，地熊蜂（Bombus terrestris，简称B. terrestris）为799米。不同农场类型间，同一熊蜂物种的最大觅食范围存在显著差异。在考虑觅食范围差异的前提下，研究发现园林熊蜂（47个巢/平方千米 vs 13个巢/平方千米）与红尾熊蜂（45个巢/平方千米 vs 22个巢/平方千米）在HLS农场的筑巢密度显著高于ELS农场。而地熊蜂（88个巢/平方千米 vs 38个巢/平方千米）与犬熊蜂（32个巢/平方千米 vs 39个巢/平方千米）的筑巢密度在两类农场间无显著差异。综合所有熊蜂物种来看，HLS管理模式对熊蜂筑巢密度具有显著的正向影响。本研究结果表明，旨在提升适宜饲用植物可获得性的针对性农业环境计划，可显著提升野生熊蜂的种群规模。