DISSOLVED ORGANIC CARBON IN SURFACE WATER AND GROUND WATER SYSTEMS IN THE CUMBERLAND GAP NATIONAL HISTORICAL PARK

Dissolved organic matter (DOM) is an important pool of reduced carbon that enters freshwater systems through partial decomposition of plant litter, microbial and animal wastes, and soil leaching. It plays a major role in aquatic systems because microorganisms use it for respiration. DOM is also a part of the aquatic food system. Because DOM is a complex mixture of organic compounds, it is most commonly measured as dissolved organic carbon (DOC) concentration. This project will test the levels of DOC in surface water and groundwater systems in the Cumberland Gap National Historical Park (CUGA), and to compare Total Organic Carbon (TOC) and Dissolved Organic Carbon (DOC) fractions obtained by filtering water samples through filters with 0.45 and 0.22 µm- pore-diameters. TOC and DOC analyses will be correlated with seasonal physio-chemical field parameters that reflect the different geological settings in the Park. Bulk DOM will also be isolated into its macromolecular components using weak anion exchange chromatography and analyzed via spectroscopic analyses. This research will establish the baseline for future investigations on how variations in weather, climate, vegetation, flow conditions, and lithology affect carbon cycling in these forested headwaters system. The broader impacts of this project integrate interdisciplinary critical zone science into the development of a long-term environmental monitoring framework for CUGA and the upper Powell River watershed. This will allow researchers to look at different aspects of the CUGA; including geology, soil science, ecology, meteorology, geomorphology, and hydrology.