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.欧洲与北美地区的农业实践变革，与熊蜂属（Bombus spp.）昆虫的分布范围缩减及局部灭绝密切相关。为遏制并扭转此类种群衰退趋势，多项农业环境计划（agri-environment schemes）已相继推行，其核心举措多为补充提供熊蜂等传粉昆虫的蜜源植物。尽管已有研究证实这类计划能够吸引大量觅食的熊蜂，但目前仍不清楚它们能否切实提升熊蜂的种群规模。本研究采用标准化样带行走调查法与分子生物技术，对比了实施授粉友好型管理方案的高级管护（Higher Level Stewardship, HLS）农场与作为对照的入门级管护（Entry Level Stewardship, ELS）农场的熊蜂种群规模。样带调查结果显示，HLS农场内的熊蜂种群丰度显著高于ELS农场。分子分析表明，不同熊蜂物种的最大觅食范围存在显著差异：园艺熊蜂（Bombus hortorum）为566米，石熊蜂（Bombus lapidarius）为714米，田野熊蜂（Bombus pascuorum）为363米，大地熊蜂（Bombus terrestris）为799米。且同一熊蜂物种在不同农场类型间的最大觅食范围也存在显著差异。考虑到觅食范围的差异，研究发现园艺熊蜂（47巢/平方公里 vs 13巢/平方公里）与石熊蜂（45巢/平方公里 vs 22巢/平方公里）在HLS农场的筑巢密度显著高于ELS农场。而大地熊蜂（88巢/平方公里 vs 38巢/平方公里）与田野熊蜂（32巢/平方公里 vs 39巢/平方公里）的筑巢密度在两类农场间未表现出显著差异。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提升作用。本研究结果表明，针对性的农业环境计划通过增加适宜蜜源植物的供给，能够切实提升野生熊蜂的种群规模。