ASSESING THE DEGRADATION OF TERRESTRIALLY DERIVED DISSOLVED ORGANIC MATTER IN THREE TEMPERATE LAKES
In lake ecosystems, both biodegradation and photodegradation of dissolved organic matter (DOM) can occur. It is not clear which of the above processes are dominant in temperate lakes and on what time-scales these processes operate. Recent research highlights a strong link between a lake ecosystem and its surrounding terrestrial environment. To test the above hypothesis, we conducted short and long-term studies that focused on the processing of terrestrially derived DOM. Three experiments were conducted to determine whether biodegradation or photodegradation was more influential. In all experiments, terrestrial DOM samples were collected via lysimeters, which were installed in wetlands surrounding Lake Lacawac, Lake Giles, and Lake Waynewood (all in the Pocono region of Pennsylvania). The first experiment was conducted at the surface of Lake Lacawac, while the second and third experiments were conducted in the laboratory using controlled environmental chambers. Experiments ranged in length from 48 hours to 90 days. Changes in DOC concentration and quality (absorbance scans) were analyzed. Initial results show that photodegradation is more important than biodegradation, but that the response was variable by lake. Distinct differences were noted between the short and long-term rates of processing.
Chris Dempsey (Co-Presenter/Co-Author), Gannon University, Biology Department, email@example.com;
Sarah Magyan (Primary Presenter/Author), Gannon University, Biology Department, firstname.lastname@example.org;