Nutrient loading to streams from adjacent land surfaces can either be retained by the stream organisms or exported downstream. This research will investigate how land use influences nutrient removal by the thin mats of algae and microbes that cover most substrates in streams (biofilms). Understanding how changes in biofilm composition can affect nutrient removal is essential as land use change continues to increase worldwide. Studies have often focused on the consequences of altering availability of a single resource such as nitrogen (N), phosphorus (P), or carbon. Many changes in land use result in changes in the availability of more than one resource, thus, there is a need to better understand the potential interactions of simultaneously varying multiple resources on biofilm community composition. Experiments supported by this award will quantify the changes that occur in the composition and function of stream biofilm in response to varied resource gradients by manipulating N+P and carbon concentrations in experimental chambers.
As landscapes are increasingly impacted by agriculture, urbanization, and industrialization, understanding the response of stream ecosystems to nutrient loading will help predict nutrient retention and export capacity of surface waters. This research will identify how biofilm community interactions alter nutrient cycling and inform land managers of potential consequences of changes in land use.
