Meeting Abstract

P3.33  Friday, Jan. 6  Effects of climate on seasonal abundance of native bees and flowers - Implications for plant-pollinator communities in the face of climate change NATER, O.H.A.*; BRUNO, J.R.; DILLON, M.E.; University of Wyoming, Laramie; University of Wyoming, Laramie; University of Wyoming, Laramie onater@uwyo.edu

Discerning the role of climate in shaping the relationship between pollinator and floral abundance is crucial for developing conservation strategies to address a potential ‘pollination crisis’. However, for most systems we lack even rudimentary data on the relationship between climate and population fluctuations of pollinators and flowers. Here we present preliminary data from an ongoing census of native bees and their floral resources. We sampled bees and plants weekly throughout the growing season (late May to mid-September) at two sites in southeastern Wyoming. We collected bees in standardized “bee cups” as well as by fixed-effort netting, and counted all flowers in 100 1-m2 quadrats in each of the sites. Native bee abundance tracked mean temperature for the first half of the growing season (late May to early July). Beginning in July, mean temperature and bee abundance diverged, with bee numbers decreasing and temperatures continuing to rise. A sharp drop in floral resources at this time likely played a role in this divergence. While bee numbers peaked in mid-June, floral abundance was highest in mid-July. Given the strong dependence of bee abundance on spring climate, the duration of the lag between peak bee and floral abundance may be driven by climate, suggesting that current and future climate change could lead to phenological mismatch between plants and their bee pollinators in this community. Further investigation of the drivers of plant-pollinator interactions and network structure will be required to predict and mitigate the potentially disruptive effect of climate change on plant-pollinator communities.