School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA,USA.
Environ Entomol. 2021 Aug 12;50(4):821-831. doi: 10.1093/ee/nvab036.
Pollination provided by bees is a critical ecosystem service for agricultural production. However, bee populations are at risk from stressors such as habitat loss, pesticides, and disease. On-farm wildflower plantings is one mitigation strategy to provide habitat and resources for bees. In many instances, government programs can subsidize the installation of these plantings for private landowners. Semi-natural habitat (SNH) in the landscape is also important for bee conservation and may alter the effectiveness of wildflower plantings. In this study, we tested the effectiveness of wildflower plantings and interactions with SNH in the landscape for promoting bee abundance and richness. Bee surveys were conducted over 2 yr at 22 sites in eastern Virginia and Maryland. Wildflower plantings, averaging 0.22 ha in size, were installed and maintained by cooperators at 10 of the sites. In total, 5,122 bees were identified from 85 species. Wildflower plantings did not alter bee communities independently, but bee abundance was greater on farms with plantings and 20-30% SNH in the landscape. Bee abundance and richness had nonlinear responses to increasing SNH in the landscape. The positive effects for richness and abundance peaked when SNH was approximately 40% of the landscape. Similar to predictions of the intermediate-landscape complexity hypothesis, increases in bee abundance at wildflower sites were only detected in simplified landscapes. Results indicate that small wildflower plantings in the Mid-Atlantic U.S. only provided conservation benefits to bee communities under specific circumstances on the scale studied, and that conserving SNH across the landscape may be a more important strategy.
传粉是农业生产的关键生态系统服务，蜜蜂是主要的传粉昆虫。然而，蜜蜂种群正面临着栖息地丧失、杀虫剂和疾病等压力。在农田中种植野花是为蜜蜂提供栖息地和资源的一种缓解策略。在许多情况下，政府计划可以为私人土地所有者补贴这些种植的安装。景观中的半自然栖息地 (SNH) 对蜜蜂的保护也很重要，并且可能会改变野花种植的效果。在这项研究中，我们测试了野花种植和景观中 SNH 的相互作用对促进蜜蜂丰度和丰富度的有效性。在弗吉尼亚州和马里兰州东部的 22 个地点进行了为期 2 年的蜜蜂调查。在 10 个地点中的合作者安装和维护了平均大小为 0.22 公顷的野花种植。总共从 85 个物种中鉴定出 5122 只蜜蜂。野花种植并不能独立地改变蜜蜂群落，但在有种植的农场和景观中 20-30%的 SNH 上，蜜蜂的丰度更大。蜜蜂的丰度和丰富度对景观中 SNH 的增加呈非线性响应。当 SNH 约占景观的 40%时，丰富度和丰度的正效应达到峰值。与中间景观复杂性假说的预测相似，只有在简化的景观中，在野花种植点的蜜蜂丰度增加才会被检测到。结果表明，在美国中大西洋地区，只有在特定情况下，规模较小的野花种植才能为蜜蜂群落提供保护效益，而在整个景观中保护 SNH 可能是一种更重要的策略。
