Saving Block Island one blade of grass at a time

Sat, 04/21/2018 - 6:00am
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“A steady sea wind sweeping across the beach carries grains of sand inland. When its motion is interrupted by a log or grass clump, the wind drops its burden of sand. Slowly, a mound builds up. Growing higher, broader, merging with other mounds, it becomes a hillock, a ridge — a dune. Rolling up the face of the dune and tumbling over its crest, the wind-blown sand gives the dune its characteristic shape — a gentle slope on the windward side and a sharp drop on the lee.”

The above description, from Dorothy Sterling’s “The Outer Lands,” is an excellent explanation of how a sand dune builds and shifts over time. 

The following passage from Sterling is also apt:

“Few places are as subject to sudden change as the dunes. Although dune life tends to progress from bare sand to dense woods, a hurricane, a fire or the hand of man can halt the progression and destroy centuries of growth in short order. The death of a single clump of Beach Grass on the crest of a dune may be enough to free the sand hill from its bonds and set it in motion.”

Beach grass (Ammophila breviligulata — ammophila meaning “sand lover”) is uniquely adapted to its environment. Beach grass thrives in nutrient-poor, dry, sandy conditions. It can withstand harsh winds and salt spray. When the plant is covered over with sand it puts up new shoots from its buried stems and rhizomes, growing a stabilizing mesh of plant parts below and within the dune. But, the rhizomatous root structure cannot endure soil compaction caused by foot or vehicle traffic.

Block Island’s dunes are nothing if not dynamic. They can be built and moved by prevailing winds. And, they can be destroyed when high winds and surf eat into the sub-dune structure of woven beach grass roots and stems.

Block Island’s dunes are also an incredibly important protective system, which functions as the ramparts for our island home. In this epoch of climate change, leading to increasing sea level rise and more extreme weather events, we have seen our dune structures compromised. Dune systems along Crescent Beach that have built up over decades (since the the 1938 hurricane) have been under siege, and in some areas, breached.

Rebuilding a sand dune system quickly is not easy. It requires a source of sand, new vegetation, and good luck. Over the past four years there has been a considerable effort made to stabilize the island’s dune systems, most notably along the south end of Corn Neck Road. The Town of New Shoreham has orchestrated the effort by placing sand, blown into the Town Beach parking lot during the winter, on the severely diminished “dune.” Beach grass culms (stems) have been purchased by the town, with donations from Block Island Residents Association, and this year, from ConserFest. Then the real work begins.

Between November and April, 9,600 culms were planted by Block Island School students, with more to be planted. The Nature Conservancy has continued the work of coordinating beach grass planting as part of the nature education program at the Block Island School.

This is the fourth year of the beach grass planting program, and thanks must go to the town for its infrastructure and budget support, to the non-government organizations for their monetary and volunteer support, and to Block Island students for their work, saving Block Island, one beach grass culm at a time.

So, spread the students’ admonishment: Stay off our beach grass!