Plants = Habitat
Insects, fish, birds, and mammals rely on a vast green infrastructure
Plant communities translate the geophysical variation of the land—its soil, topography, and so on—into the living habitats that sustain life. Conserving several intact examples of every habitat is an important strategy for sustaining the natural benefits plants provide and for maintaining the full diversity of species that depend on them.
To this end, we have collaborated with The Nature Conservancy on a new report that sets the targets, down to the parcel level, for land protection that ensures plant diversity across the entire region in the face of climate change.
We also work to bank the seeds of rare species for the future and help to restore habitats on public lands. When necessary, we improve degraded environments as we restore plant populations—adding soils, removing invasive plants, or bolstering eroded slopes.
Stories about some of our restoration projects appear below.
Native Plants Return to a Mountaintop
Though only 1,528 feet high, the summit of Cadillac Mountain in Acadia National Park in Maine is one of the most visited on the eastern seaboard, receiving about 500,000 visitors a year. Their trampling feet, along with pummeling rains, have worn down the summit’s alpine plants and fragile soils.
In 2015, the National Park Service contracted with Native Plant Trust for a multi-year experimental restoration of the summit’s plant communities. The project started with an inventory of the summit’s vascular (leafy) plants funded by Friends of Acadia. Our survey establishes a baseline for monitoring these plant communities going forward.
Our research botanist Arthur Haines and contract botanist Jill Weber combed the entire 18-acre summit and created a list of 145 species. They also staked out 147 plots along four transects (measured lines) and determined the percentage of each species within each plot. They identified five rare plant species and found the first climate change signal: some species, such as pitch pine (Pinus rigida), have already moved up from lower elevations and established small summit colonies.
For the next phase, Conservation staff marked locations for more than 60 restoration test plots, including several areas already fenced off to prevent trampling. With Acadia staff and contractors, we collected 20,000 seeds from 25 species on the summit, both common and rare plants, so that we could propagate plants for restoration experiments. We then sowed portions of the seed in 2-square-meter experimental plots to test different seed-sowing methods, or treatments—and learned that simply adding seeds to the poor soils may not be enough to support restoration. We had more success the next season (2017) , when we planted seedlings grown at our Nasami Farm nursery from seed collected at Cadillac.
In 2018, we began testing ways to add and hold organic matter and soil on the windy summit and steep slopes. We have sterilized soil; used coir mats to keep soil, seeds, and seedlings in place; and installed 12 x 16-inch flats of small plugs that have already rooted together.
The work continues, as we seek to learn which techniques are the most effective, least expensive, and can be replicated on other degraded mountaintops.
Collecting Seed to Restore a Storm-ravaged Coast
After a multi-year project to collect seeds to restore coastal native plant communities damaged by Hurricane Sandy, replanting is underway.
If you lined up the 868 bags of seeds Conservation staff and interns collected along coastline damaged by Hurricane Sandy in five New England states, the grapefruit-sized sacks would fill a school bus.
The seeds come from plants native to the coastal habitats that were flooded, washed out, or buried by the 2012 superstorm. Over three years, we visited 127 sites and collected seed from more than 215,000 plants. These represent Native Plant Trust's contribution to a $2.3 million initiative, in partnership with North Carolina Botanic Garden and Mid-Atlantic Regional Seed Bank, to ensure that locally sourced, genetically appropriate plants are available for restoration projects from Maine to Virginia.
The partners collected seed from fifty species of native plants in our respective parts of the coastline to restore all types of coastal habitat—from sub-tidal zones, dunes, and salt marshes to freshwater wetlands, forests, rivers, and streams. To date, we have provided seed for fourteen restoration projects in New England, five of which have begun propagation or planting.
One successful project is the restoration of the 11-acre salt marsh at Sachuest Point National Wildlife Refuge in Middletown, RI. The hurricane inundated the salt marsh and made it clear that to save the habitat, it would be necessary to raise its elevation. The U.S. Fish & Wildlife Service refuge manager decided to lay down a new layer of soil and sand, varying from an inch to a foot thick, and sculpt new upland mounds. Over two years, refuge staff and volunteers planted 38,000 plugs (deep-rooted seedlings) of native grasses and rushes grown from seed we collected. Last spring, the staff experimented with sowing seed directly into the ground. Self-seeded asters (Aster spp.), seaside goldenrod (Solidago sempervirens), and other species have filled in around the planted species. Together, the plants literally anchor the marsh, which is critical habitat for migrating birds and the nursery for about a dozen fish species.
The rest of the seed we collected is banked at federal facilities and available for land managers to use to rehabilitate salt marshes, bolster flood resiliency on riverbanks, and establish native species on land exposed after dam removal or clearing invasive species.
Funded by the federal Department of the Interior, the project is also the first large-scale, coordinated seed-banking effort in the eastern United States. Until this initiative, restoration projects in the eastern states have relied primarily on plants and seeds from other parts of the country. This was also the first significant expansion to the east of the western-focused Seeds of Success program, run by the Bureau of Land Management, of which we have been a partner for over a decade.
Why Is This Wild Rice Declining?
A federal agency asked our Conservation staff to find out
By Michael Piantedosi, NEPCoP/Seed Bank Coordinator
Our Conservation staff recently wrapped up three years of experiments to determine what could be causing a decline of wild rice (Zizania aquatica) in two Massachusetts locations owned by the U.S. Fish & Wildlife Service: the Sudbury River and the Great Meadows National Wildlife Refuge Concord Impoundment. Wild rice is a crucial food for many animals, including several duck species, great blue heron, and migrating waterfowl that rely on the Great Meadows refuge.
Anecdotal reports noted a decline in wild rice in these two locations, where the plant had formerly thrived in its favored growing conditions: slow-moving water and freshwater marsh. In recent years, however, invasive aquatic plants had spread in each of these areas. Were the invasive plants choking out the wild rice, or were other factors involved, such as an uptick in wildlife feasting on the rice before it could germinate? The agency contracted with our Conservation staff for three years to research the ecology of wild rice, restoration techniques, and seed germination.
We designed our first experiment to gauge the effects of wildlife—fish, rodents, and waterfowl—on the growth and survival of wild rice. We constructed two types of exclosures, structures that function as fences in the water. The first type was designed to limit access by fish, rodents, and birds. The second type allowed fish to pass through but kept out rodents and birds. Preliminary data from this experiment suggest that none of these animals are eating enough wild rice to inhibit the plant's germination and survival in the research areas.
Anecdotally, some researchers think that invasive species are a major reason for the decline of wild rice. Understanding the dynamic between invasive plants and wild rice is important to our strategy for restoring wild rice. Invasive species of particular concern in the research sites are water chestnut (Trapa natans) on the Sudbury River and American lotus (Nelumbo lutea) at the Great Meadows refuge, which respectively are the dominant competition for habitat and, likely, for nutrients.
Hypothesizing that invasive plants were a significant factor affecting wild rice germination and growth, we built four open quadrats at each location to test this. (Quadrats are square frames that isolate a sampling plot within a larger area. In this case, we located them randomly within potential wild rice habitat.) We sowed half of the quadrats with wild rice seed collected from plants on the sites and did not sow any seed in the other half, which served as control plots. In half of the quadrats, we also regularly removed the invasive water chestnut and lotus.
The highest survival rates appeared in the quadrats where we had sown seed and manually removed invasive plants. We found the most significant negative impact to wild rice when invasive plant plant species were able to enter, either from existing seeds embedded in the mud under the water, or possibly from plants penetrating the quadrats.
The data collected in these experiments allows us to better understand the potential for wild rice restoration at both of the research sites. Regardless, it appears that much of the potential habitat suitable to wild rice proliferation at Great Meadows has been compromised by the complete domination of surface water by American lotus.
From this preliminary data, we strongly recommend future research that focuses on the relationship of invasive plant species, particularly the species noted here, with that of wild rice and its habitat. Further research may also factor in the effects of water chemistry, nutrient loading, and climate-related events (such as storm surges, extensive flooding, drought, etc.) on wild rice and its habitat.