Rare Wetlands in the Midst of an Old Trash Dump

*Please note, this blog post was originally published in The Inquirer and Mirror on August 11th, 2016  in the article series called Island Ecology. The Foundation’s Science staff will be regularly contributing to our local newspaper and reprinting articles here the following week.*

On the southeast end of Nantucket Island there is a large tract of open land with no real access roads or trails. Just south of the Milestone Road and east of Tom Nevers, before you get to ‘Sconset is a Nantucket Conservation Foundation property called the ‘Sconset Dump. Unless you’re a hunter, birder or hard-core plant enthusiast, you probably haven’t wandered through this area and with good reason. This property is dense shrubby, scrubby, boggy wetlands with few upland areas and no walking trails – but it represents one of the more unique wetland properties owned by the Nantucket Conservation Foundation.

Named the ‘Sconset Dump as a nod to its history, this property hosts the highest variety of wetland communities on island, including a unique man-made wetland with numerous rare plants. From the north-side of the Milestone Road, the ‘Sconset Dump receives water from Gibbs Pond and the Milestone Cranberry Bog. Water from the bogs flows under Milestone Road, moves through this property as a mix of flowing surface water and groundwater that occasionally springs up to the surface and all this water eventually makes its way south to Tom Nevers Pond. In between the Bogs and the Pond exist a dense network of shrub swamps, Tupelo and Red Maple swamps, sandy open fens with carnivorous plants and Sphagnum mossy wetlands with a stream or two running through. Pulses of increased water during and just after cranberry harvest times helped create this vast wetland network of open water, streams and boggy land. All of these different wetlands leads to many unique and even rare plants and also is what makes this a hard place to walk through!

So you might be wondering why this gorgeous and unique property has the name ‘Sconset Dump? Right in the center of the property is a small upland area, surrounded on all sides by wetlands and, at some point, this higher ground started serving as an informal dumping ground for the southeast end of the island. The origination of this dump is lost in the memory of Nantucketers, but a glance at the Nantucket aerial photos from 1938 so the dump area in operation. The actual dump officially closed in 1971 with the Foundation assuming ownership in 1979. Over the years it was open, the Sconset Dump received everything from refrigerators and large metal appliances to everyday household waste. This is one reason no trail network exists on this property; the only upland area is covered in broken glass and rusting metal as a remnant of this unmanaged dump. Common historic practice at the ‘Sconset Dump was to conduct occasional controlled burns to reduce household trash, with the larger, unburnable debris pushed into piles around the dump. Eventually a wide but shallow firebreak was bulldozed in a horseshoe surrounding the upland dumping area to help contain the management fires. This single action of a bulldozer created one of the most botanically unique and rarest wetland types on island!

The wetland in this central bulldozer scrape has very acidic, sandy soil which doesn’t hold a lot of nutrients for growing plants. Additionally, as you many have noticed in your garden, sand soil is porous, making it difficult to hold water. This wetland was formed by a series of groundwater springs and surface water from surrounding areas running right through the scrape, keeping the soil at least moist if not covered in standing water all year long. Only a very select few plants can actually survive in the nutrient-poor and wet soils present in the scrape.

Did you notice the mention of carnivorous plants above? Carnivorous plants – plants that attract, capture and digest prey – thrive in nutrient-poor wetlands. The prey they digest, typically insects, provide nutrients like nitrogen and phosphorus that these plants need to survive and can’t find in the soil. In the scrape at the ‘Sconset Dump, we can find two different species of sundews (Drosera) and a bladderwort (Utricularia), all carnivorous. Sundews use sweet but sticky nectaries on their leaves to attract prey while bladderworts use pressure bladders on their roots to suck in unsuspecting microbes for dinner. (We have blogged about carnivorous plants before – learn more here!)

In addition to the charismatic carnivorous plants, this unique wetland is home to at least 6 plants rare in Massachusetts. The plants that live in this wetland require not only wet, nutrient-poor soils, but also a lack of shade and competition to survive. In 2008, the Foundation got permission to cut and thin out woody shrubs that had begun encroaching into the scrape area. Since then, we have monitored the rare plant populations which have been increasing thanks to our management! Not everything is rare or carnivorous in these wetlands. One of this author’s favorite flowering plants can be found in and around this property, sheep laurel (Kalmia angustifolia) – keep an eye out for its birthday cake flowers in the spring!

From an unregulated dump and variable water flows from a large cranberry production to today, an area of the highest wetland diversity on island, thriving rare plant populations and the occasional carnivorous plant; the Sconset Dump represents one of the very important ways that the Nantucket Conservation Foundation not only protects rare pristine natural habitats but works to improve and promote the places that make Nantucket unique!

The Nantucket Conservation Foundation is a private, non-profit land trust that depends contributions from our members to support our science projects, conservation property acquisitions and land management efforts. If you are not already a member, please join us!  www.nantucketconservation.org