State of the Plants
How Nantucket measures up with the rest of New England
Last March, the New England Wildflower Society (NEWFS) published its first State of the Plants, the “most comprehensive assessment of New England’s plant communities ever assembled.” This document uses botanical data, historical records, and cultural information to assess the current status of the New England flora, highlighting “Habitats in Trouble”. Organized by habitat, the report focuses on the representative plants, their status, primary threats, and conservation actions for each ecosystem.
It should be a badge of pride for Nantucketers that two of the five habitats highlighted as “at risk” are prevalent on Nantucket and already under protection; the sandplain grasslands/heathlands and estuarine marshes.
Sandplain Grasslands and Heathlands
Nantucket has some of the largest expanses of intact sandplain grassland and heathland habitat. With much of this landscape lost to development up and down the Atlantic coast, almost 90% of the world’s sandplain grassland occurs on Nantucket, Martha’s Vineyard, and a small slice of Long Island. We know these habitats for their Black Huckleberry, sweet Low- and Highbush Blueberries, fragrant Northern Bayberry, and Little Blue-stem grasses rolling in the winds. These plant communities are host to a number of regionally and globally rare species as well including the Eastern Silvery Aster, Nantucket Shadbush, and the spectacular New England Blazing Star, among others.
While plants are the cornerstone for ecosystems everywhere, sandplain grasslands and coastal heathlands support a diversity of life found in few, if any, other locations. Northern Harrier hawks and Short-eared Owls hunt and nest in the grassland/shrub mix. Grasshopper sparrows eat, sleep, and nest on the ground – impossible to do off-island where skunks, raccoons, and other nest predators are about. Grasslands and heathlands are host to a multitude of insect fauna including at least 19 rare species. This includes important pollinators, dragonflies, butterflies, and moths.
These highly productive ecosystems at the land-sea interface are an amazing example of ecosystem engineering; fixing carbon, trapping and building sediments, filtering pollutants, and buffering against tidal surges. Like Nantucketers themselves, plants in these systems must be a hardy lot. They have to be able to conserve freshwater, withstand salt water flooding, with many sequestering or excluding salt.
Throughout New England, it’s estimated that about 37% of salt marshes have been lost to development or other man-made controls. A major threat to existing marshes is salt marsh die-back – a phenomenon with browning (die back) of the high marsh grasses resulting in overall marsh degradation. The phenomenon affects about 60% of New England marshes. Here on Nantucket, the Nantucket Conservation Foundation has begun to notice salt marsh die-back in the Medouie Creek area.
In addition to development, estuarine habitats are threatened by altered hydrology (ditching for example), nutrient loading, and sea level rise due to climate change. Conservation actions under way on Nantucket and elsewhere include restoring tidal flow (as seen at Medouie Creek), reducing nutrient loads (such as fertilizers and septic seepage), and removal of invasives such as common reed (Phragmites australis).
Nantucket was ahead of its time in creating so much open space, and, in doing so, it created some of the best examples of sandplain grassland and coastal heathland on earth. With conservation as well as state and federal regulations, estuarine marshes are also well-protected. We are lucky to be on the side of preservation and maintenance rather than restoration and reclamation seen in other areas.
To learn more about the State of the Plants and what you can do in your own yard to minimize threats, join the Nantucket Biodiversity Initiative Friday, November 13th, 7pm at the Atheneum. Dr. Elizabeth Farnsworth, Senior Research Ecologist with the New England Wildflower Society, will be the keynote speaker for the 6th Biennial Nantucket Biodiversity Initiative Research Conference. Her Keynote Address: “State of New England’s Native Plants: Challenges and Opportunities for Conserving Coastal Habitats” will be in the Great Hall followed by a reception and book signing. Free and open to the public. For more information or to register, go to www.nantucketbiodiversityinitiative.org