UTILIZATION OF SPECIFIC ULTRAVIOLET ABSORBANCE TO CLASSIFY VARIABLE LABILITY OF DISSOLVED ORGANIC CARBON COLLECTED IN TERRESTRIAL AND STREAM ENVIRONMENTS

Dissolved organic carbon (DOC) is a component of all soil and aquatic ecosystems. DOC is a gage of ecological productivity in ecosystems and is a staple bioavailable energy source for microbes. Yet, in high concentrations it can also facilitate the transport of metals. These variable effects of DOC in ecosystems are partially determined by the quality of the DOC. This study sought to better understand if the quality of DOC can be traced to identifiable sources from within variable soil types. Sampling was conducted in the Wolf Creek watershed in western North Carolina during the fall of 2015. Sample sites were selected because of their locations within two primary areas: thin, organic soils over bedrock and organic horizons over deep (> 30 cm deep) soils. Filtered samples from these sites were analyzed for specific ultraviolet (UV) absorption at 254nm and results were plotted against DOC concentrations to investigate whether or not the two areas generate different qualities of DOC. This study will provide a broad scope understanding of variable DOC sources and the quality of DOC they contribute to watershed ecosystems. This understanding of DOC characteristics could potentially aid in further studies assessing the pooling and continued transport of DOC and potentially associated trace metals in ecosystems. Finally, this study will lead to a better understanding of topographically regulated sources/sinks of DOC in headwater catchments.