Monitoring Phragmites

The invasive form of Phragmites (Phragmites australis) -of European lineage- grows in wet areas including fresh or brackish marshes, creeks, edges of ponds and lakes, ditches, and the dune systems of barrier coastal islands. Disturbance and eutrophication (increased nitrogen levels), are key factors in the establishment and spread of Phragmites. Even though this invasive lineage is utilized by plants and animals, negative impacts have been reported for birds, plants, fish and other wildlife, as well as wetland biogeochemical processes.

The invasive Phragmites has colonized vast areas of tidal wetlands in the Chesapeake Bay during recent decades; in some areas the invasion is so extensive that management is almost impossible. However, there are still some sub-estuaries where invasion has been minimal and restoration and conservation are still possible. The Patuxent River is one of those sub-estuaries!

One of the most common techniques used for the control and removal of Phragmites is chemical treatment (herbicide spraying). Phragmites patches along the Patuxent River have been sprayed in various occasions to control the spread; the last spraying occurred during the fall of 2014, including a patch located along Jug Bay’s railroad bed.

In an effort to monitor the response and recovery of the marsh after chemical spraying of Phragmites, three transects with five 1m2 plots each were established within the treated area along the railroad bed. All the plots were measured (with the help of volunteers) before the spraying took place to establish baseline data. The plots will continue to be monitored annually to record marsh response and recovery through time. Main variables being measured include species presence and density and diameter of Phragmites stems.