An essential step toward ultimate protection of the Potomac River is monitoring the watershed’s streams and buffers to determine the value of restoration actions. Streams run through many land uses, creating a patchwork of buffer characteristics. Monitoring shows where buffers could be restored with streamside forests.

Thirty monitoring sites have been selected in Maryland and Virginia. All monitoring sites are properties with a history of cattle grazing and/or pasture habitat, since these land use activities are prevalent throughout the Upper Potomac Watershed. Each property was enrolled in a riparian forest buffer restoration plan under the Conservation Reserve Enhancement Program. Riparian forest buffers fulfill several important functions by reducing the amount of nutrients and pollution entering a stream and by stabilizing erodible stream banks. They also benefit fish, insects and other wildlife by shading the stream channel and lowering water temperatures to acceptable levels for these organisms.

Each spring and summer, teams from the Virginia Department of Forestry, Maryland Department of Natural Resources, and Ducks Unlimited Inc. visit these sites and collect a variety of data, to measure the success and performance of the riparian tree plantings. These teams monitor a half-acre plot of trees at each site to determine what species are planted, whether or not each planting is still alive, and how tall each planting is. Within this same half-acre plot the degree of natural regeneration occurring each year is monitored. Natural regeneration includes the grasses, trees, and other plants that germinate and establish without being planted by human hands. These plants may also include invasive species, which are undesirable non-native plants that compete with the tree plantings for resources and may ultimately negatively influence the survival and growth of our riparian plantings.

A second aspect of the monitoring program focuses on in-stream conditions and how they are impacted by riparian restoration activities. The science teams monitor various water quality parameters, from nutrient levels of nitrates and phosphates to measures of stream acidity and oxygen levels. Furthermore, samples of aquatic insects called benthic macroinvertebrates are collected, which provides a measure of stream health based on the composition of species and their sensitivity to levels of pollution. Other factors being examined are stream temperature and the stability of the stream bank and stream channel.