CARBON AND NITROGEN CYCLING IN AN AGRICULTURAL IMPOUNDED RIVER

The East Fork River is an impounded river that is a tributary to the Ohio River in the Mississippi headwaters. The watershed is primarily used for agriculture, and the reservoir is used both recreationally and for drinking water purposes. The Environmental Protection Agency and the Army Corps of Engineers have been closely monitoring this watershed for nutrient levels, dissolved oxygen and many other factors for years. Understanding how impounding a river in an agricultural watershed affects the cycling of carbon and nitrogen is an important aspect of evaluating global climate change. This study helps cap the carbon and nitrogen cycling in the watershed through a time-series study of dissolved and emitted greenhouse gases.

Floating flux chambers are utilized to collect air samples over six sites across the reservoir. At those six sites samples are collected for analysis of dissolved greenhouse gases, nutrients, and dissolved organic carbon. A YSI sonde is used to measure dissolved oxygen, pH, temperature, chlorophyll, and conductivity. Data from the fall and winter months show that while the values are higher in the fall, methane, carbon dioxide, and nitrous oxide are emitted from all sites across the reservoir.