Wetland Habitats

Marsh and Shrub Wetland comprises 241 acres in Eaton.  Emergent marsh and shrub swamp systems have a broad range of flood regimes, sometimes controlled by the presence or departure of beavers, but mostly controlled by groundwater. This system, which is an important food source for many species, is often grouped into three broad habitat categories: wet meadows, emergent marshes, and scrub-shrub wetlands.  Many wildlife species use marsh and shrub wetlands including common species like red-winged blackbirds, beavers, and painted turtles. Marsh and shrub wetlands are also important for bank swallows, American woodcocks, moose, and bald eagles. Development is a threat to these habitats mostly from driveways and roads that fragment wetlands or change the flow of water. The loss of an upland habitat around a marsh or shrub wetland also increases the amount of pollution and sedimentation threatening the habitat. Another constant threat to marsh and shrub wetlands is invasive plants such as Japanese knotweed that compete with native vegetation. Some conservation strategies for marsh and shrub wetlands are restoration and protection of these important habitats.

Eaton contans 31 acres of Northern Swamps which are forested wetlands including black spruce peat swamps and forest seeps. Black spruce peat swamps are typically found in closed or stagnant basins with limited drainage. These swamps have a forest or woodland structure, but often surround open peatlands. Seeps occur where groundwater emerges at the soil surface and begins flowing into a stream. Despite their small size, they support a distinctive suite of plant species, and have value as wildlife habitat for the tricolored bat, Cape May warbler, American water shrew, purple finch, and hoary bat, as well as some amphibians. Between 2004 and 2015 the New Hampshire Department of Environmental Services documented approximately 950 acres of wetlands lost in New Hampshire through development activities. Development of swamps, surrounding uplands, and impacts from fragmenting features like roads are all threats to this habitat. Other threats include increased temperatures that can cause changes in species composition, and eventual conversion to a different habitat type.

There are 51 acres of Temperate Swamps in Eaton.  These are also forested swamps typically found in isolated or stagnant basins with saturated, organic soils.  They provide habitat for the silver-haired bat, little brown myotis, Canada warbler, and eastern red bat. They also provide a number of functions such as flood control, pollutant filters, shoreline stabilization, sediment retention and erosion control, food web productivity, recreation, and education. Threats to temperate swamps include habitat degradation from insect pests such as the hemlock woolly adelgid, since hemlock is a common component of temperate swamps across New Hampshire. Inputs of sedimentation, insecticides, and fertilizers are sources of pollution that threaten temperate swamp habitats. Actions to conserve temperate swamps include supporting the Division of Forests and Lands in the implementation of the hemlock woolly adelgid action plan, and working with foresters to use Best Management Practices outlined in the document ‘Good Forestry in the Granite State.’

Peatland habitats are extremely important for carbon sequestration on a local and global scale.  They comprise 25 acres of land in Eaton.  The water in peatlands has low nutrient content and typically high acidity caused by limited groundwater input and surface runoff. These environmental conditions are such that plant and animal material take a very long time to decompose. This organic material contains carbon and other nutrients, storing it away and slowly releasing it into the atmosphere. Drainage and destruction of peatlands releases this carbon into the atmosphere more quickly, increasing greenhouse gases today. Conservation of the 11 different natural communities that comprise peatlands is also vital to the continued existence of many rare plant and wildlife species.

The American black duck, spotted turtle, black-billed cuckoo, and olive-sided flycatcher are all species of greatest conservation need found in peatland habitats. Typical vegetation in a peatland includes sphagnum moss, leather leaf, northern white cedar, and American larch. Threats to peatland habitats are development, altered hydrology (amount and flow of water), and unsustainable forest harvesting. Non-point source pollutants, such as road salt, lawn fertilizers, and pesticides, also threaten this habitat by altering the acidity and nutrients. Establishing buffers around this habitat is one conservation strategy that will help minimize the threats to peatland habitats.

Vernal Pools are wetland depressions characterized by small size, physical isolation from other wetlands, and periods of flooding and drying. Vernal pools can be found in almost every other habitat type and many wildlife species use them as a place to take a quick drink as they are passing through the area. Some species though are vernal pool-dependant and the loss of this habitat can result in local extinction of these species such as the blue-spotted salamander, Jefferson salamander, Eastern ribbon snake, and Blanding's turtle.

The loss of vernal pool habitat due to development is therefore a huge threat, but the surrounding habitat is also just as important as the vernal pool itself. Most of the wildlife species that use vernal pools also spend a great deal of time in the surrounding habitat. Removing the tree canopy around a vernal pool also changes the amount of sunlight reaching the pool and can alter the temperature and the flooding and drying cycle. Some of the conservation strategies for vernal pools include habitat protection and supporting regulations that do not allow dredging and filling of vernal pools.

Intermittant Streams are small streams and wetlands at the highest end of a watershed. Many headwater streams are scoured by ice in winter, flood in the spring and fall, and are dry in the summer. Because wide variations in water flow and temperature make life difficult in these streams a unique group of plants, amphibians, and insects are adapted to survive in these difficult conditions. Small streams perform an important ecological funciton by trapping leaves and other nitrogen sources, preventing them from accumulating in the lower reaches of the river.

Headwater streams are places where forest and stream habitats converge, leading to high densities of insects around the streams. Stoneflies, mayflies, and dragonflies, whose larvae live underwater, are found alongside upland insects such as moths, beetles, and grasshoppers. This concentration of food attracts predators from the surrounding forest including northern long-eared bat, red-shouldered hawk, raccoon and ribbon snake.

Many species take advantage of the relative safety of headwater streams for reproduction. Green frogs and spring and two-lined salamanders lay their eggs in intermittent, fishless streams. Common white suckers and rainbow smelt, two fish species, migrate every year into small streams to spawn. Headwater streams also can act as travel corridors for wildlife such as mink, otter, beaver, forest birds, and forest-dwelling bats.

The isolation and harsh conditions of headwater streams can also provide native fish with a refuge from introduced species. Natives such as banded sunfish, redfin pickerel, and redbelly dace can thrive in headwater streams, but are over-run by introduced fish in the more stable and often degraded habitats of larger rivers and lakes.

Despite their ecological value, headwater streams are often overlooked by conservation efforts and are not covered by New Hampshire’s Comprehensive Shoreland Protection Act. Their small size makes them vulnerable to human impacts, particularly those caused by human development. Use of groundwater by residential or commercial wells can cause streams to dry up. Roads, driveways, and poorly designed or placed culverts fragment streams, causing sedimentation, and isolate wildlife populations. Runoff from paved surfaces can introduce pollutants, increase flooding, and cause spikes in stream temperature. These and other threats are compounded by the tendency to dismiss small streams because they don’t command the same recreational and aesthetic appeal of larger lakes and rivers, and because they are often considered too small to provide important habitat.

Conserving land from development around headwater streams will allow for the natural processes that prevent flooding, maintain water quality, quantity, and temperature, recycle nutrients, and provide food and habitat at the source and downstream. Maintaining intact, undeveloped headwaters may also buffer the predicted higher temperatures and increased flooding and rainfall associated with climate change.