An assessment of the native invertebrate pollinator community and floral sources in grasslands of eastern North Dakota
Graduation Date
2015
Document Type
Thesis
Program
Other
Program
Thesis (M.S.)--Humboldt State University, Natural Resources: Wildlife, 2015
Committee Chair Name
Ned H. Euliss
Committee Chair Affiliation
HSU Faculty or Staff
Keywords
Grassland, Pollinators, Floral sources, CRP, Bees, North Dakota, Prairie, Pollen, Humboldt State College -- Theses -- Wildlife, Native
Abstract
Pollinators are critical for the proper functioning of natural ecosystems and they benefit or are required by many agricultural crops. Despite their importance, there is little information available to enhance restoration efforts or manage habitats to benefit pollinators, especially for native species. My study was conceived to determine the abundance, richness and diet breadth of native invertebrate pollinators using native and restored prairie grasslands in the prairie pothole region (PPR) of eastern North Dakota. I compared native pollinators on native grasslands managed by the U.S. Fish and Wildlife Service (FWS) and on Conservation Reserve Program (CRP) grasslands because they collectively constitute the largest land area of potential pollinator habitat in the United States PPR. Using vane traps and collecting pollinators visiting individual flowers, I evaluated change in species abundance, richness and pollinator/plant interactions biweekly from May to September in 2012 and 2013. I did not detect a significant difference in native pollinator abundance or richness between native and restored prairie grasslands. However, I did detect a decrease in native pollinator and a higher species turnover in CRP grasslands relative to my native grassland sites in 2013. Pollinator richness and abundance changed among seasons and locations, likely due to diverse pollinator taxa responding to temporal and spatial variations in the floral community. In total, I observed 283 interactions corresponding to 55 plant taxa and 31 native bee taxa resulting in 177 unique links. Interactions and links were significantly higher on native grasslands, likely reflecting the higher diversity of blooming forbs in native prairie grasslands relative to CRP. Native bees were caught mostly on native plants in native grasslands and on introduced plant species on my CRP sites. My study suggests that pollinator abundance and richness in restored grasslands was similar to that in native grasslands. However, the floral composition varied by grassland type and CRP grasslands may not be as effective at providing stable pollinator habitat. My analyses of pollen loads of individual pollinators identified 53 plant species that could be added to seed mixtures to diversify native and restored sites for pollinators. Similarly, identifying management disturbances for native grasslands and mature CRP restorations would increase the diversity of plant species important to native pollinators to enhance the overall value to a diverse pollinator community.
Recommended Citation
Bryant, Russ Blackwood, "An assessment of the native invertebrate pollinator community and floral sources in grasslands of eastern North Dakota" (2015). Cal Poly Humboldt theses and projects. 1254.
https://digitalcommons.humboldt.edu/etd/1254
https://scholarworks.calstate.edu/concern/theses/fb494b686