Ellis Katherine E, Barbercheck Mary E
Department of Entomology, The Pennsylvania State University, 501 Agricultural Sciences and Industries Building, University Park, PA, 16802.
Environ Entomol. 2015 Aug;44(4):999-1010. doi: 10.1093/ee/nvv086. Epub 2015 Jun 6.
The incorporation of cover crops into annual crop rotations is one practice that is used in the Mid-Atlantic United States to manage soil fertility, suppress weeds, and control erosion. Additionally, flowering cover crops have the potential to support beneficial insect communities, such as native bees. Because of the current declines in managed honey bee colonies, the conservation of native bee communities is critical to maintaining "free" pollination services. However, native bees are negatively affected by agricultural intensification and are also in decline across North America. We conducted two experiments to assess the potential of flowering cover crops to act as a conservation resource for native bees. We evaluated the effects of cover crop diversity and fall planting date on floral resource availability and visitation by native bees for overwintering flowering cover crop species commonly used in the Mid-Atlantic region. Cover crop species, crop rotation schedule, and plant diversity significantly influenced floral resource availability. Different cover crop species not only had different blooming phenologies and winter survival responses to planting date, but attracted unique bee communities. Flower density was the primary factor influencing frequency of bee visitation across cover crop diversity and fall planting date treatments. The results from these experiments will be useful for informing recommendations on the applied use of flowering cover crops for pollinator conservation purposes.
将覆盖作物纳入一年生作物轮作是美国中大西洋地区用于管理土壤肥力、抑制杂草和控制侵蚀的一种做法。此外，开花覆盖作物有潜力支持有益昆虫群落，如本地蜜蜂。由于目前管理的蜂群数量下降，保护本地蜜蜂群落对于维持“免费”授粉服务至关重要。然而，本地蜜蜂受到农业集约化的负面影响，在北美也呈下降趋势。我们进行了两项实验，以评估开花覆盖作物作为本地蜜蜂保护资源的潜力。我们评估了覆盖作物多样性和秋季种植日期对中大西洋地区常用的越冬开花覆盖作物物种的花卉资源可用性和本地蜜蜂访花情况的影响。覆盖作物种类、作物轮作时间表和植物多样性显著影响花卉资源可用性。不同的覆盖作物种类不仅有不同的开花物候和对种植日期的冬季存活反应，还吸引了独特的蜜蜂群落。花密度是影响不同覆盖作物多样性和秋季种植日期处理下蜜蜂访花频率的主要因素。这些实验的结果将有助于为出于传粉者保护目的而应用开花覆盖作物的建议提供信息。
