LONG-TERM CHANGES IN NATIVE BEE DIVERSITY, ABUNDANCE, AND PHENOLOGY

(WYO-449-10)

Dramatic declines in honey bee populations in the US over the last 25 years have prompted calls for alternative wild and managed pollinators that could offset some of the lost pollination services. Native bees are particularly appealing as they are already responsible for over $3.5 billion worth of food and feed crops in the US. Unfortunately, recent studies in the UK and continental Europe suggest that many native bee populations are declining rapidly. Despite the current economic and ecological importance of native bees in the US and our potential increased dependence on them, we know very little about the status of native bee populations in this country. However, extensive collections of native bees in the Laramie area 35 years ago provide a unique opportunity to assess the status of a diverse native bee community. Tepedino and Stanton sampled native bees and bee-pollinated flowers weekly throughout the growing season in 1975 and 1976 using standardized methodologies. Their collections reside in the UW Insect Museum, which also has native bee records extending back to 1888. We propose to re-sample at the same sites with the same techniques and to mine museum records to determine whether the phenology and diversity of the native bee and plant communities has changed over the last 35 to 100 years. Mean temperatures in the area have increased by nearly three times the global average over the last 35 years. Such striking changes in climate may lead to similarly pronounced changes in the phenology and diversity of native plants and bees. In addition to assessing the effects of long-term climate change on these communities, we will also look at finer-scale determinants of bee activity and abundance. Micro weather station data combined with temperature measurements of bee models in the field will allow us to generate "climate envelopes" for individual species, thereby allowing us to look for mechanistic explanations for larger-scale patterns of abundance and diversity. Native bees provide important pollination services for food and feed crops and are therefore critical for protecting our natural resource base and guaranteeing the future safety of our food supply. This study will provide important baseline data on the status of native bee populations which may have several applied outcomes. Understanding the effects of global climate change on the match between phenologies of pollinators and the plants they pollinate is critical for crops that depend on this match (e.g., almonds). Pollinators can be excellent indicators of ecological recovery after restoration, but their use in this capacity depends on extensive baseline data, which this study will provide. Finally, the extensive data on the relationships between floral resources and bee abundance and diversity could prove useful in developing effective strategies for leveraging native bees for increased agricultural production.

USDA CRIS Project Information Link: 0221014