While globally rare, sandplain grassland and heathland vegetation communities currently exist in fairly high abundance on Nantucket and Martha’s Vineyard as well as a few locations on Cape Cod and Long Island. These unique early successional communities are composed of plant species that are adapted to and often require disturbance of some kind to thrive. Disturbance can take the form of strong winds, salt spray, fire, mowing or combinations of these. In the absence or reduction of regular disturbance, sandplain grasslands and heathlands are often out-competed by shrubs and trees over time.
The Foundation’s Head of the Plains property is one of our largest sandplain grassland and heathland sites on Nantucket and a focus of research and management activities designed to maintain and promote these rare communities. Our Science and Stewardship Department is currently conducting a comprehensive research project to examine aggressive soil disturbance as a management technique to reduce woody species and reestablish sandplain grassland and heathland vegetation communities. This research builds off the successful study we completed in 2013 in the Serengeti area of the Middle Moors. As a component of our work at Head of the Plains, we are also studying the response of rare plants, insect communities, small mammal populations and songbirds using these managed areas to document ecosystem-wide effects.
This research is taking place in an area that was overgrown with dense, tall shrubs adjacent to existing, high quality sandplain grassland and heathland habitat that may serve as a seed source for sandplain-associated plants. During the 2016 field season, we set up and conducted pre-treatment monitoring in four study areas: brushcut + harrow (soil disturbance), brushcut + no harrow, and two reference areas with different soil types (one in sandplain heathland habitat and one in sandplain grassland habitat). A disc harrow pulled behind a tractor was used to implement aggressive soil disturbance. The brushcut and harrow treatments took place in late winter 2017.
This research project will be monitored for at least 5 years to follow vegetation shifts and resulting changes in how various wildlife utilize these managed areas. Visual assessment of the brushcut + harrow area indicates that little bluestem grass (Schizachyrium scoparium) and other grassland-associated plants have colonized this area at a much higher rate than in the brushcut + no harrow unit. Additionally, in the second growing season post-treatment, we observed a large population of the rare sandplain blue-eyed grass (Sisyrinchium fuscatum) in the brushcut + harrow area.
The results of this management will be compared to communities that have previously been managed by prescribed fire at Head of the Plains. We are particularly interested in understanding the effects of soil disturbance in this area, which likely has a significant “seed bank” of sandplain grassland-associated plants, including many rare species.
Our science staff are also founding members and active participants in the Sandplain Grassland Network, a regional partnership among researchers and managers that formed in 2016 to advance understanding and effectiveness of the management of sandplain grasslands. Results of the research we are conducting at Head of the Plains is being shared with our regional colleagues through this group.