Two longleaf pine savanna communities, upland woodlands and wet pine flatwoods, occur in Louisiana. Because these communities differ in soil profiles, hydrology, topography, and floral composition and diversity, the objective of this study was to determine how bee diversity and composition differed between them. We surveyed three upland woodlands and one flatwood site over a four year period. Our results indicated higher richness and abundance of bees in uplands compared to the wet flatwood. Upland sites consistently contained about 10 more species and 2.5 times as many individuals. Rarefaction curves indicated similar to higher rates of species accumulation of upland sites compared to the wet site. Similarity in species composition was higher between upland sites than between uplands and the wet site. Differences in diversity are discussed in relation to differences between savanna types, age and size of preserves, and fire management. Size of the preserve appeared to be less important than floral diversity and soil type. From a management perspective, this study suggested newly restored savannas obtain high bee diversity relatively quickly, and small preserves are capable of serving as significant reservoirs of bees.