1. Effects of Prairie Management on Soil Characteristics and Bees METHODS RESULTS  Soil Characteristics Analysis of variance (ANOVA) suggests that there are significant differences between prairie management types in reference to the bulk density and pH of the soil as shown in Figures 1 and 2 which supports our hypothesis. The bulk density of the top soil increased in sites that supported cattle. However, the bulk density of the bottom soil core (6-12 inches) remained relatively constant. This suggests that the top 6 inches of soil is more sensitive to compaction due to the weight of the grazing cattle compared to the soil core below. Overall, the pH of top soils of grazed sites is lower compared to prairies without cattle. This is potentially due to the fact that manure has an acidifying effect on soil which is further supported by the smaller range of pH found within the bottom soil cores throughout all sites. All dominating soil types according to the soil triangle (Cane 1991) are sandy loams for top soils of prairies and half of the bottom soil treatments as shown in Table 1. The other half of the bottom soils have silt loam as the dominant type for the bottom soil cores and these two soil types are relatively close on the soil triangle but are of somewhat different compositions, which is surprising. Christina Vercillo¹, Brittany Buckles¹, ², Alexandra Harmon-Threatt¹, ² ¹ School of Integrative Biology, ² Department of Entomology, University of Illinois at Urbana-Champaign Bulk Density Dry Mass/Volume (g/cm³) pH Mettler Toledo Soil Type Soil Composition REFERENCES 1. Cane, 1991. Soils of ground-nesting bees (Hymenoptera: Apoidea): texture, moisture, cell depth and climate. Journal of the Kansas Entomological Society, 406-413. 2. Håkansson and Lipiec, 2000. A review of the usefulness of relative bulk density values in studies of soil structure and compaction. Soil and Tillage Research 53.2: 71-85. 3. Haynes and Williams, 1992. Changes in soil solution composition and pH in urine‐affected areas of pasture. Journal of soil Science 43.2: 323-334. 4. Kurz, 2010. Is patch-burn grazing damaging Missouri’s native prairie? Privately published (reprints available from Don Kurz at dkurz@ socket. net). 5. Moissett, 2010. Bee Basics: An Introduction to Our Native Bees. USDA, Forest Service. 6. O'Toole and Raw, 1991. Bees of the World. Blandford Press. ACKNOWLEDGEMENTS We would like to thank the coordinator of IB299, Karen Sears for giving us the opportunity to work together on this project, the Missouri Department of Conservation for maps and sampling permits, field assistants: Nick Anderson and Nicole Wonderlin, soil data assistant, Jonathan Balthazar, and Keelan Lang and our local bee expert Michael Arduser for help in identifying bee species. BurnHayPBG NewPBG Old Top Soil Type 65% sandy loam 40% sandy loam 67% sandy loam 55% sandy loam Bottom Soil Type 70% sandy loam 47% silt loam 72% sandy loam 49% silt loam *** ** Figure 1. Differences of bulk density in management type for top soil are indicated by uppercase letters and bottom soil is indicated by lowercase letters. The top and bottom soil cores were significantly different from each other within the management types of burn, hay, and PBG new, as indicated by the stars. Significant differences were observed between PBG new and burn. Figure 2. Differences of pH in management type for top soil are indicated by uppercase letters and bottom soil is indicated by lowercase letters. The top and bottom soil cores were significantly different from each other within the management types of burn and hay, as indicated by the stars. Significant differences were observed in the following: top soil cores in PBG new and burn, PBG old and burn, and PBG new and hay, bottom soil cores in hay and burn, PBG new and burn, PBG old and burn, and PBG new and hay. Table 1. Soil type is determined by using respective percentages of sand, silt, and clay layers found in the soil samples collected from each site. The soil triangle shown to the left was used to identify soil type categories. The table below shows which soil types were recorded most frequently in each site type and the percentages of those soil types. The total core was a foot long and the division between top and bottom was made at six inches.  Prairie Management Types Prescribed burning and haying are common prairie management types. Haying involves mowing and drying grass to create feed for cattle. Patch burn grazing is a process in which the prairie is divided into patches and burned in a rotation, then cattle are introduced to graze. 4 Sites classified as PBG new were burned about 2 years ago and sites classified as PBG old were burned more than 2 years ago.  Soil Characteristics Prairie management types have the potential to affect certain characteristics of the soil. Soil is the basis for biodiversity which makes it an important factor in conservation efforts. Surprisingly, 80% of bee species nest in the soil. 6 Some species may have limited distribution because of a lack of suitable nesting soil. 5 The three soil characteristics of interest in this study are bulk density, pH, and soil type based on insightful evidence and suggestions from scientific literature. 1,2,3  Hypotheses Prairie management will affect soil characteristics such as bulk density, pH, and soil types which may alter wild bee communities. For example, some bee species avoid nesting in silt or clay, 1 cattle waste could make the soil too acidic, 3 or excessive compaction from the cattle may result in a bulk density that is too high for suitable nesting. 4 INTRODUCTION CONCLUSIONS Figure 3. Total numbers of bees found in prairie sites per management site. Although none of these values are significantly different from each other, burn sites are shown to have the highest abundance.  Bees Although no significant difference was found in bee abundance between management types, burned sites had the highest average bee abundance (Figure 3) compared to the others. The trends in burned sites are as follows: lowest bulk densities among management types in both top and bottom soils, the highest pH among management types in both top and bottom soils, and a predominantly sandy loam soil core. It is possible that ground-nesting bees prefer these soil conditions. Burn HayPBG