Current Nature: Resilient Restoration

On the banks of Long Pond, the Linda Loring Nature Foundation has been working on a restoration project that provides an example of how sea level rise can affect even seemingly inland areas of our island.

As many of you know, Long Pond is connected to Madaket Harbor via the historic Madaket Ditch which was dug in the 1670s by English colonists and native Wampanoag. Because of this estuary connection, Long Pond itself is brackish and undergoes regular tidal turnover. In addition to the water being salty, this connection also means that Long Pond is subject to predicted sea level rise. Looking at various sea level rise scenarios expected with future climate change, even the most conservative projections show that sea level rise will impact the shoreline of the North Head of Long Pond, home to the Linda Loring Nature Foundation.

The Linda Loring Nature Foundation (LLNF) is dedicated to preserving and protecting Nantucket’s biologically diverse ecosystems. As part of the strategic and master planning processes, LLNF determined that portions of the Eel Point Road property are particularly vulnerable to sea level rise (SLR) impacts. Specifically, sea level rise projections show that much of the LLNF property around the North Head of Long Pond will be inundated by salt water in the near and long term. Even the upland areas are vulnerable because the low-lying access to these areas will be cut off by rising water levels.

The LLNF sees itself as a potential mitigation space for climate change impacts; protecting surrounding infrastructure, homes, and creating resilient landscapes to bolster against predicted impacts. To this end, the LLNF began its “Resilient Restoration” project in earnest with funding from the Community Foundation for Nantucket and the ReMain Nantucket Fund. LLNF engaged Wilkinson Ecological, an ecological design and restoration company with a history of work on-island. The design plan enables LLNF to create a native, biodiverse habitat that blends in with the surrounding upland sandplain grassland on the north side and the brackish wetland bordering the pond. The plan incorporates known sea level rise projections and, thus, the planting plan uses plants specifically tolerant to the expected conditions. Establishing a diverse, healthy pond edge and upland with native species will increase biodiversity and act as a buffer to the environmental impacts.

There are three aspects to this project with a focus on building a resilient landscape in the face of climate change: Retreat – removing any structures from the at-risk area, Accommodate – planting the bank of the pond edge with brackish-tolerant species to accommodate rising sea water, and Prepare – planting the upland with native, diverse species to restore the sandplain grassland habitat.

The first step in making the area around the North Head of Long Pond more resilient is to “retreat” by removing all aspects of the built environment and refraining from further building at this site. After removing the man-made structures and fencing this past fall, the next phase of the project involved removing a suite of non-native and invasive plants around the banks of the pond and in the nearby upland. The area was then graded to create a more natural profile and erosion control blankets put into place to help stabilize the soil for the short term. A native seed mix was strewn overtop to initiate planting to further stabilize the area.

Instead of restoring the area to what has persisted there in the past, LLNF is working towards a transitional landscape with the influence of brackish water as part of the planting plan. The plan facilitates the transition from fresh to brackish water – a restoration practice that achieves what would naturally happen, but in a shorter time frame. The pond shore edge is being planted with native, brackish-tolerant plant species.

In addition to the impacts projected with sea level rise, the Nantucket Coastal Resilience Plan (CRP) calls for the ecological restoration of the areas around northern Long Pond and the North Head of Long Pond. One priority project that is proposed in the CRP is the raising of Madaket Road and creating a bridge or multiple culverts where Madaket Road crosses over Long Pond. The LLNF project accommodates more brackish water onto the LLNF property, which is expected with the proposed increased water flow. Initiating this project now, would allow time for the plants to establish properly prior to any future changes to the culverts. In taking on the brackish water resulting from expected sea level rise and storm surge, the LLNF property can help mitigate the effects of climate change protecting the surrounding infrastructure and homes.

LLNF research and conservation staff have been monitoring the salinity of the North Head of Long Pond since 2020, noting tidal influence and fluctuation. In 2022, water level meters were installed at two locations to monitor tide flow. These data will help establish a baseline of information prior to any changes.

Research shows that areas with higher biodiversity are more resilient to change, so the project area will be better prepared for the expected effects of climate change. Relative to most other habitats, healthy and diverse native grasslands may be more resilient to drought and other severe weather events expected to increase with climate change.

For the restoration itself, LLNF has been collecting seeds from the surrounding landscape for the purpose of having site-specific seed for the project. These property-sourced seeds are being supplemented with other seed material as well as adult plants for establishment and soil stabilization. All species will be native and the native ecotypes will be matched as much as possible. The coming growing season will see more plant establishment as the project progresses.

This project has been in the planning phase for the past few years as part of the LLNF’s Master Plan for the property. Recognizing the vulnerability of this site and the role LLNF can play in mitigating for the effects of climate change, the LLNF is committed to retreat and resilient restoration of this area. As a demonstration area for resilient restoration, LLNF hopes that the direct impacts of this project will be broader within the community, allowing people to see what is possible for retreat and restoration.

To see this in-progress project in-person, go to the LLNF website (www.llnf.org) for information on guided walks in the area. As the project gets further underway, LLNF hopes to open the property fully to the public and provide volunteer opportunities to help with plantings and other community projects.