Honey Bee Colony Resource Acquisition, Population Growth, and Pollen Foraging in Diversified Native Grass-Wildflower Grazing System

Compounding evidence suggests a current or impending sixth mass extinction event and pollinator crisis. While several factors contribute to pollinator declines, the most notable driver is habitat loss and degradation. Agricultural grasslands provide crucial habitat for wild and domesticated fauna, regulate water and nutrient cycles, store carbon, and maintain soil stabilization. However, conventional tall fescue pastures, which dominate the southeastern United States, limit pollinator habitat, reduce ecosystem services, and diminish cattle productivity if infected with toxic endophytes. Establishing wildflowers (WFs) and native warm season grasses (NWSGs) into tall fescue pastures has the potential to boost both pollinator ecosystem services and cattle productivity. This study monitored the differences in honey bee colony health, productivity, and pollen foraging behavior between diversified and conventional grazing pastures in south west Virginia. Chapter 1 sought to evaluate the health and productivity of hives within NWSGW+ diversified and conventional grazing systems. Chapter 2 sought to 1) determine whether honey bees used sown wildflower species in diversified pastures as significant sources of pollen, 2) compare species composition and nutritive value of pollen collected from hives within diversified and conventional pasture systems, and 3) evaluate temporal trends in pollen collection. Floral surveys revealed diversified pastures had almost 4x greater mean bloom density than conventional pastures, with over half of all blooms recorded in diversified pastures belonging to unsown species. Results from this study suggest that colonies in diversified pasture systems may have a slight advantage in population resource acquisition, population growth, and winter survival following the first year of establishment, though further research is needed. Pollen DNA metabarcoding revealed that honey bees in both diversified and conventional pasture systems have similar diets, and that sown species were foraged upon primarily in the fall. Samples collected from diversified pasture systems yielded greater pollen weight, species richness, and protein content. In conjunction with previous research, these results indicate that diversified pastures could ultimately provide a more complex nutritional support system for pollinators in grazing agroecosystems. However, individual pasture renovation may not be large enough to yield statistically significant differences in honey bee colony success.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Larcom, Raven Miranda

Chair dc:contributor.committeechair

• Tracy, Benjamin Franklin

Committee members dc:contributor.committeemember

• Reid, John Leighton
• Wilson, James McKee

• pollination
• pollinators
• southwest Virginia agriculture
• ecosystem services

Statement dc:rights

• Creative Commons Attribution 4.0 International

Licence dc:rights.uri

• http://creativecommons.org/licenses/by/4.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:36598

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/116194