Collaborative Research: Effects of pulsed floral resources on pollinator population dynamics

这项研究将探索景观变化的一个结果，即花朵的时间和可用性，如何影响大黄蜂的种群。大黄蜂是北美许多农作物和野花授粉的一种重要的本地蜜蜂群体。大黄蜂很重要，因为我们吃的三分之一以上的食物来自农作物，这些作物在某种程度上取决于它们提供的授粉类型。尽管非本土蜜蜂仍然是农业授粉的基石，但鉴于蜜蜂面临的持续挑战，本土蜜蜂越来越成为农业关注的焦点。健康的本地蜜蜂种群依赖于持续的花粉和花蜜供应。然而，气候变化带来的变幻莫测的天气，以及包括集约化农业在内的人类活动，极大地改变了这些花卉资源的可获得性。研究人员将研究花期和可获得性的变化如何影响大黄蜂的数量。这项研究与过去的研究相比是一个重大的进步，过去的研究使用蜜蜂访问花朵的模式来得出关于蜜蜂种群和群落的整体健康的广泛结论。相比之下，目前的研究将专注于蜂箱的繁殖成功。这些结果将是制定促进蜜蜂数量旺盛、确保粮食安全以及保护生物多样性的战略的关键。具体地说，该项目结合了操纵性田间实验和原始人口种群模型，以评估年内资源变化(资源脉冲)对大黄蜂种群动态的影响。这些实验将在北加州的一种占主导地位的熊蜂物种--熊蜂身上进行。研究人员将进行实验，系统地改变花朵的可获得性和时间。然后，他们将测量个体群体的生死率(例如，工蚁产量、工蚁存活率和蜂后产量)如何取决于集群生命周期中不同时间的花卉资源的可用性。为了确保一致的蜂群质量基线，所有的测量都将在实验室饲养的蜂群上进行，这些蜂群是从野生收集的蜂王开始的。实验结果将与人口统计模型相结合，以预测不同景观条件下蜜蜂的长期种群生存能力。这项研究将回答正在进行的景观变化将如何影响熊蜂和其他蜜蜂物种的问题。它还将为蜜蜂和其他群居昆虫的种群生存分析提供一个以前缺失的框架。

This research will explore how one result of landscape change, the timing and availability of flowers, affects populations of bumble bees, a prominent group of native bees that pollinate many crops and wildflowers in North America. Bumble bees are important because more than one-third of the food we eat comes from crops that depend to some degree on the type of pollination they provide. Although non-native honey bees remain a cornerstone of agricultural pollination, native bees are increasingly the focus of agricultural attention in light of ongoing challenges facing honey bees. Healthy populations of native bees rely on continuous supplies of pollen and nectar. However, the availability of these floral resources has been dramatically altered by unpredictable weather associated with changing climate, and by human activities, including intensive agriculture. The investigators will study how changes in the timing and availability of flowers affect the number of bumble bees. This research is a significant advance over past studies, which used patterns of bee visits to flowers to make broad conclusions about the overall health of bee populations and communities. In contrast, the current study will focus on reproductive success of bee hives. The results will be key to developing strategies to promote robust populations of bees and ensure food security, as well as to conserve biological diversity. Specifically, the project combines manipulative field experiments and original demographic population models to assess effects of within-year resource variation (resource pulses) on population dynamics of bumble bees. The experiments will be conducted with Bombus vosnesenskii, a dominant bumble bee species in Northern California. Investigators will conduct experiments in which flower availability and timing are systematically altered. They will then measure how vital rates of individual colonies (e.g., worker production, worker survival, and queen production) depend on the availability of floral resources at different times in the colony life cycle. To ensure a consistent baseline of hive quality, all measurements will be made on lab-reared colonies started from wild-collected queens. Experimental results will be combined with demographic models to predict long-term population viability of bees under different landscape conditions. This research will answer questions about how ongoing landscape change will affect Bombus vosnesenskii and other bee species. It also will provide a previously-missing framework for population viability analysis of bees and other social insects.