Sustainable Grazing to Control Phragmites australis

November 20, 2012

ENST graduate student Jennifer Brundage examines the effectiveness of grazing by goats to control common reed, an invasive wetland grass known as Phragmites Australis.

Phragmites Australis—An Invasive Grass in Wetlands
In many regions of North America, land managers are using herbicides to control the invasive grass Phragmites australis. While herbicide control is often effective, it is labor, cost, and energy-intensive and often results in impacts to non-target native plants. Now, Marine-Estuarine-Environmental Science major Jennifer Brundage is studying how to control this grass in a sustainable way – through grazing by goats.

Phragmites australis is found in wetlands throughout temperate regions of the world. While native genotypes exist in America, Eurasian genotypes have been spreading widely in the Chesapeake Bay watershed for about 200 years. Phragmites typically replaces diverse natural marsh plant communities with monocultures. “This grass is usually controlled with herbicide, which can have damaging environmental impacts,” Jennifer explains.  As an alternative to these harmful methods, she is conducting research using goats to eliminate the grass in an environmentally and economically sustainable way.

Using Grazing Instead of Herbicide

Jennifer’s study, “Prescribed Grazing as a Means to Control Common Reed in Maryland Wetlands,” is one of the first of its kind in the U.S.– only one published study has been conducted in North America previously, which used goats, sheep and cattle to control Phragmites populations in New Jersey. Jennifer is expanding on this past work. “I am taking their research to the next level by studying whether this grazing has any negative effects on nutrient cycling,” Jennifer explains.  Nutrients are a leading cause of impaired water quality in the Chesapeake Bay, and this study will examine whether grazing can be a sustainable means of reaching the Chesapeake 2000 Bay Agreement goals for reducing invasive species without endangering goals for water quality. While grazing is a common management tool in Europe for restoring biodiversity, this goes against prevailing wisdom in the U.S., especially for wetlands.  

Goat Grazing in Beltsville

Jennifer conducts her research at a Phragmites patch at the U.S. Department of Agriculture’s Beltsville Agricultural Research Center. The patch has been randomly divided into four grazed and four ungrazed plots. Goats, which use less land than cattle, have had proven results in past research. Jennifer monitors changes in the vegetation, soil nutrients, and groundwater nutrients. USDA staff care for the animals and monitor their health.

After she gathers her results, Jennifer hopes her findings will encourage land managers in the Chesapeake Bay region and elsewhere to use sustainable grazing practices for controlling invasive species, rather than environmentally-damaging herbicides. She also hopes that future ENST graduate students will be interested in continuing and expanding on her study. 

Aiming to Find an Outdoor Career 

Jennifer believes  that her coursework and research in ENST and her ecological consulting job in England have prepared her for an outdoor career after graduation in 2009. “I am interested in working as an ecologist in a variety of areas, like wetlands, stream restoration, and forest ecology. This research and my coursework have raised my interest in getting involved in Chesapeake Bay restoration efforts in my future career,” Jennifer says.