Browsing by Author "Cariveau, Daniel"
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Item Comparison of current and historic wild bee body length, head width, and intertegular distances(2017-04-20) Vohs, Michelle; Cariveau, DanielNative bees are critical pollinators that all life depends on. Body size of of pollinators can influence fitness of individual bees and pollination effectiveness. This study investigated the change in body length, intertegular distance, and head width in several species of bees. Intertegular distance is the space between a bee’s wing bases or tegulae, and can be used to estimate bee body size. The literature has not addressed a comparison study with these measurements in mind. Global changes such as climate and land-use change may influence bee body size may change more over time with successional change with warming temperatures. Some bee species depend only on single species of flowers, or nest in stem cavities, so their bodies must coevolve with that plant species. Seven species of bees were selected for this study from Hennepin, Ramsey, Anoka, and surrounding counties. Current bees from the Minnesota Bee Survey and historical bees from the University of Minnesota Insect Collection were used for this comparison study. Over 300 bees were measured and included historical bees from the early 1900s to the 1940s and current bees from the 1990s to 2016. Then a two-tailed t-test was used to determine if bee body length, head width, and intertegular distances had changed over time. The preliminary results from a t-test have indicated the changes of body lengths on these species of bees was minimal and statistically insignificant, though these findings are still useful and can be applied to future research.Item R Code and Data for: Prescribed fire increases the number of ground-nesting bee nests in tallgrass prairie remnants(2023-02-15) Brokaw, Julia, N; Cariveau, Daniel; Portman, Zachary, M; Bruninga-Socolar, Bethanne; broka028@umn.edu; Brokaw, Julia, NBees were collected using emergence traps from June 13, 2019 to August 22, 2019 from four remnant prairie sites in western Minnesota that were patch burned in spring of 2019 to determine whether ground-nesting bees prefer to nest in burned or unburned areas of prairies. Bees were identified to species and the number of nests was used to determine community similarity using Bray-Curtis index and to determine the Effective Number of Species of bees. For each site and sample round, we also measured various characteristics of the floral community and microhabitat that may relate to bee nesting preferences. We measured floral abundance by counting flowers and determining average flowers per site and round. We also measured flower diversity by identifying flowering species every site and round. We determined floral community similarity using the Bray-Curtis index and determined the Effective Number of Species using the species and abundance data for the floral community. We also measured mean percent bare ground, mean vegetative cover, and mean thatch depth per site and same round.