Isaacson Fen

Fen Preservation at the Isaacson Preserve

Bruce in fen


A fen is a unique wetland environment that receives most of its water from underground sources. This water source leads to an abnormal water chemistry (i.e., high pH, low dissolved oxygen) that supports a rare ecosystem and sometimes, very rare plants. One such fen is found on our Isaacson Preserve but is currently threatened by the aggressively spreading wetland plant, Phragmites australis (commonly referred to as ‘Phragmites’). Phragmites has a reputation of forming dense monocultures, outcompeting native plants and changing the chemistry of the water. In order to prevent the spread of Phragmites into new parts of the fen, we cut its stem at the height of summer before it can move its carbon stores into the safety of its roots. This technique of battling Phragmites has been well studied and the Nature Conservancy has documented its effectiveness. Dr. Ellen Kearns – a volunteer researcher for the PRLC and former board member– began a study of the effectiveness of Phragmites cutting at the Isaacson Fen in spring of 2006. See Dr. Kearns’ report here.

Since 2010, the PRLC has maintained its own study plots in the fen and recorded the abundance of Phragmites stems after successive years of cutting. The results of this research will be published in a Fen Management report, winter 2012. High school and college students interested in plant physiology and ecology are encouraged to contact the Pound Ridge Land Conservancy for more information about volunteer opportunities for research in the fens of the Isaacson.