Wild Bee Assemblages of the Southeast Prairies and Sandstone Prairies Biologically Unique Landscapes

The Southeast Prairies Biologically Unique Landscape (BUL) is part of the Southeast Nebraska Flagship Initiative (a partnership that includes The Nature Conservancy, Northern Prairies Land Trust, Spring Creek Prairie Audubon Center and the Nebraska Game and Parks Commission) which, under the Nebraska Natural Legacy Plan, implements a proactive approach to conserving non–game wildlife and biological diversity. In the Southeast Prairies BUL the overall goal is to determine how to best manage prairies while maintaining plant–insect relationships crucial for system functioning. More specifically, although previous work included taxa such as ground beetles and ants, the most recent and final project focused on wild bee abundance and diversity in grasslands of the BUL with the following objectives:

Goals

• Determine whether wild bee assemblages differ among grassland types: The dominant three types of grasslands in the BUL— remnant prairie, grazed pasture, and CRP plantings—were sampled and bee abundance, species richness, and diversity measured. Species were also categorized by sociality, foraging capacity, nesting behavior, and floral specificity.

• Examine the importance of local habitat quality to the wild bee community: The species richness, abundance, and density of blooming forbs were measured at each study site and correlations to bee species richness, abundance, and diversity were tested. The number of pollen types found on collected bees was also measured to make comparisons between grassland types and to examine similarities to the local blooming forb communities.

• Examine the importance of landscape composition to the wild bee community: The number of land cover types within four foraging ranges of the wild bee community were determined and assigned a habitat suitability score. Several habitat connectivity measurements were calculated for suitable nesting and foraging patches that lay within each foraging range. The importance of each land cover type and connectivity measure were examined and used for modeling the abundance distributions of important bee groups across the whole BUL.

Current Status

All field work has been completed on this project and analyses thus far have revealed the importance of blooming forb abundance for most groups of wild bees, but varying importance of suitable nesting habitats between groups. The scale at which landscape attributes are most influential on the bee community largely corresponds to the estimated foraging capacities of the bees. Finally, upon completion of modeling bee abundance across the landscape, areas where connectivity of suitable habitat patches could be improved are being identified to aid in conservation efforts for pollination services.

A Male bee (Bombus griseocollis) on goldenrod (Solidago canadensis). Photo: Bethany Teeters
A Male bee (Bombus griseocollis) on goldenrod (Solidago canadensis). Photo: Bethany Teeters
Principal Investigator(s)
-Craig R. Allen, NE CFWRU
-Chris Helzer, The Nature Conservancy
Graduate Student(s)
-Bethany Teeters, Ph.D.
Project Duration
June 2009 - December 2015
Funding
-National Science Foundation IGERT Program
-Nebraska Game and Parks Commission
Project Location
Southeast Nebraska (Pawnee, Johnson, and Richardson Counties)