Amphibians and aquatic invertebrates have complex life histories that link aquatic and terrestrial food webs. It has been suggested that amphibian reproduction is an important source of carbon to some aquatic systems. This process of energy flow may be shaped by shifts in habitat selection in response to predators. We hypothesized that predators decrease colonization and oviposition of prey, reducing active inputs. Thus predation risk is expected to shift the relative amounts of active and passive subsidies. We manipulated the presence of fish predators in aquatic mesocosms. Results suggest hylid treefrog eggs and hydrophilid beetles were less abundant in predator treatments. This difference in oviposition and colonization translated into small reductions in calories and ash free dry mass of active inputs. However, passive allochthonous inputs were more than double active amounts and variable, therefore relative amounts of active and passive inputs did not differ across the levels of predation risk.

Historic cartographic sources, historical accounts, and ethnographic and archaeological data are used help reconstruct past settlement patterns and land uses that together acted to shape the changing cultural landscape of the Virginia Commonwealth University Walter and Inger Rice for Environmental Studies (Rice Center). The Rice Center is located in Charles City County along the north bank of the James River between Richmond and Williamsburg. Presented is a baseline description of the present day condition of the Rice Center property. This is followed by a detailed account of the physiographic and ecological changes that occurred along the Lower James River since the end of the Pleistocene. A cultural context section summarizes the prehistory and history of the Rice Center setting from when humans are first known to have arrived approximately 11,500 years ago through present day. Land use and land use impacts are then analyzed within the chronological/cultural units detailed in this cultural context section. This information is synthesized and applied to a time line reconstruction of the Rice Center environment. While the naturally occurring changes to the Lower James River setting are detailed, emphasis of this study is on how human land use helped shape the Rice Center environment through time.

Differences in microbial function via extracellular enzyme activity (EEA) were investigated to determine the potential effects of hydrology and plant-soil-microbe interactions in a young non-tidal freshwater riparian wetland. To study these relationships, three plots were established along a moisture gradient (Wet, Intermediate, Dry) within VCU Rice Center Within each main plot, five subplots were left undisturbed while another five were cleared of all above-ground plant biomass. Homogenized soil cores (top 10 cm) were analyzed for pH, redox, C:N, soil organic matter (SOM) content, saturation, and temperature. Microbial function was assessed using extracellular enzyme analysis. For most enzymes, a site difference was observed due to soil moisture content, which had an effect on soil pH, redox potential, and plant community composition. For most extracellular enzymes the presence of vegetation was associated with higher activity. It is important to note that reestablishing native hydrologic and vegetated conditions are paramount in achieving previous functionality.