Birding at Ponemah (photo by Ben Kimball for the NH Natural Heritage Bureau)

Ponemah Bog

Area:  Ponemah Bog
Trails:  Bog Trail, Bypass Trail
Region:  NH - Southwest  
Location:  Amherst, NH
Rating:  Easy  
Features:  Kettle hole bog, rare plant species
Distance:  0.8 mile  
Elevation Gain:  Minimal  
Hiking Time:  Typical: 0:25  
Outing Duration:  Actual: 0:45   Typical: 1:15  
Season:  Variable
Last Updated:  01/18/2015  
Author:  New Hampshire Natural Heritage Bureau

This information has been reproduced (with permission) from New Hampshire Natural Heritage Bureau. Below you'll find trail information as well as detailed natural information.

Kettle Hole Bogs   

About 18,000 years ago, New Hampshire was covered by a continental ice sheet almost a mile thick. Kettle hole bogs are found where big chunks of glacial ice were stranded and partially buried in the landscape as the glaciers melted. The ice chunks subsequently melted, leaving ponds in depressions in the ground, with no hydrologic inlets or outlets.

Over thousands of years, peat moss progressively filled in the kettle holes from the edges inward toward the pond centers. Most still have a central bog pond with a floating mat border, while some have filled the kettles entirely with peat, obscuring the former ponds under floating or grounded peat mats. Precipitation is the primary water source for these peatlands, but their watersheds are often small and they have very limited terrestrial runoff influence.

Kettle hole bog peatland system at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau) A typical natural community sequence from the upland border towards the center of the kettle hole is marshy moat (not present here), tall shrub fen or black spruce swamp, followed by a dense leather-leaf / black spruce bog zone, and then a floating, reddish-colored open moss carpet with extremely dwarfed shrubs, and patches of Sphagnum moss pools and mud-bottoms. In many examples, such as this one, there may still be open water in the center of the bog.

The vegetation of kettle hole bogs is dominated by species indicative of nutrient-poor conditions, such as scattered, stunted black spruce, numerous dwarf heath shrubs (such as leather-leaf, small cranberry, sheep laurel, and bog laurel), liverworts, bladderworts, and white beak-rushes.

Kettle hole bogs often occur in isolation of other wetland systems. They are broadly distributed in N.H., but concentrated in the central and southern portions of the state where kettle hole formation in glacial outwash was more abundant.
 

Rhododendron canadense (rhodora) (photo by Ben Kimball for the NH Natural Heritage Bureau)

Tuft of cotton grass at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)


Utricularia cornuta (horned bladderwort) flower at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)

Larix laricina (eastern larch) needles at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)

Hawk (Accipiter sp.) at Ponemah (photo by Ben Kimball for the NH Natural Heritage Bureau)
 

Map of Ponemah Bog (map by Ben Kimball for NH Natural Heritage Bureau)


Trail Guide   

Kettle hole bog system (photo by Ben Kimball for the NH Natural Heritage Bureau) The trail network here is about 3/4 mile long and takes about 45 minutes to complete at a leisurely pace. The early part of the trail is a woods path. The part in the bog is all on narrow boardwalks. Please stay on the trails as portions of them cross private land.

From the parking area, head east on the Bog Trail (yellow blazes) into the woods. The dry forest here consists of white and pitch pine trees as well as a variety of oaks and a few red maples. Lowbush blueberry occurs in the understory. Look and listen for whip-poor-wills and eastern towhees. At a trail junction, the Bypass Trail (red blazes) continues straight towards the bog. Bear right and walk to a wooden observation deck overlooking the bog. From here you see most of the site, including the peat mat, the pond, and the upland forest edge.

Continuing on the trail, pass a small marshy swamp. At the next junction with the Bypass Trail, bear right and descend the slope to the wetland’s edge.

Stepping onto the boardwalks, you arrive at the edge of the peatland. Thousands of years ago this entire basin was open water, a pond about 100 acres in size. Over time, shrubs that are specialized in growing at the edges of ponds, such as water willow (Decodon verticillatus) and leatherleaf (Chamaedaphne calyculata), grew out into the open water. Sphagnum moss then grew on the wet stems of these shrubs and the whole mass slowly spread over the surface, providing a mat for other plants to take root in. Eventually, the accumulation of living and dead moss and plant matter allows other plants to grow, and peat gradually fills the pond. This is a classic example of a form of ecological succession called hydrarch succession.

Observation platform at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)


Today, the shrub thicket here at the edge of the bog is a highbush blueberry - mountain holly wooded fen community. Common heath shrubs that can be seen are sheep laurel (Kalmia angustifolia), bog laurel (Kalmia polifolia), leatherleaf (Chamaedaphne calyculata), bog rosemary (Andromeda polifolia var. glaucophylla), highbush blueberry (Vaccinium corymbosum), winterberry (Ilex verticillata), and rhodora (Rhododendron canadense). Many of these plants have adaptations such as hairy leaves that allow them to conserve moisture in the acidic bog environment. Black spruce and larch trees also grow well here.

A little farther along, the shrubs diminish and you enter a zone where the species composition changes and the peatland is more open. Here soft tufts of cotton-grass (Eriophorum virginicum) bob in the breeze. The natural community type transitions to Sphagnum rubellum - small cranberry moss carpet, with occasional microhabitats and other communities (such as mudbottoms) embedded within.

Andromeda polifolia var. glaucophylla (bog rosemary) (photo by Ben Kimball for the NH Natural Heritage Bureau) Scars from old peat-harvesting ditches are apparent here a short way from the boardwalk, sometimes looking like muddy lines in the peat mat. Features that may be similar in appearance are the tracks made by animals that live in and around the bog as they head for the open water.

In addition to the bog’s acidity, which inhibits the growth of many species, it is a very nutrient-poor setting due to anaerobic (low oxygen) conditions which slow the decomposition of dead organic matter. Several species offset the lack of nutrients by trapping and digesting insects. These include pitcher plants (Sarracenia purpurea), horned bladderworts (Utricularia cornuta), and tiny sundews (Drosera rotundifolia), all of which can be seen low to the ground on the mat.

A typical characteristic of this saturated, nutrient-poor setting is dwarfed vegetation. Trees that are able to survive out here do so in a stunted, bonsai-like form, putting on little woody growth each year and never rising very high.

A few acres of open water remain in the center of the bog, surrounded by the Sphagnum mat, which is likely floating. Turtles are often spotted sunning in various locations around the pond. Muskrat and heron can also be seen here. Plants found in and around the water of the pond include arrow arum (Peltandra virginica), water willow (Decodon verticillatus), and white waterlily (Nymphaea odorata).

An assortment of native New Hampshire orchid species grow in this bog. Their showy blooms can best be seen in the late spring and early to mid summer. A wide variety of birds can be seen at the Sanctuary throughout the year, including blue jay, hawks, warblers, nuthatches, and sparrows. Additionally, the bog is home to many colorful dragonflies and damselflies of the Odonata family.

Follow the rest of the trail to return to the parking area. Be careful leaving the bog as there is sometimes more water at the edges (a "moat") due to runoff from the upland.
 
Acer rubrum (red maple) at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)


Drosera rotundifolia (round-leaved sundew) on the Sphagnum mat at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)


 


NH - Southwest



Trail at Ponemah Bog (photo by Ben Kimball for the NH Natural Heritage Bureau)

Decodon verticillatus (coastal water willow) at Ponemah (photo by Ben Kimball for the NH Natural Heritage Bureau)
  Driving Directions   

From Nashua:
  • Take Rte. 101A west for 5 miles.
  • Turn right on Boston Post Rd.
  • Go 2 miles, then turn left on Stearns Rd.
  • Go 0.3 miles, then take a left on Rhodora Dr. and go straight ahead to parking for the Sanctuary.

From Milford/Amherst:
  • Go east on Rte. 101A for 0.5 miles, then turn left on Rte. 122.
  • Immediately turn right on Stearns Rd and go 1.1 miles.
  • Turn right on Rhodora Dr. and go straight ahead to parking for the Sanctuary.

Property Use Guidelines   

Please, for the protection of the area and its inhabitants, and for everyone’s safety and enjoyment:
  • Foot travel only; please stay on the marked trails
  • Walk only on the boardwalk in the bog
  • No pets, horses, bicycles, or motor vehicles allowed
  • No hunting, firearms, camping, fires, swimming, or smoking
  • Do not collect or disturb plants or animals
  • Please respect private property

Credits   

Ponemah Bog trailhead (photo by Ben Kimball for the NH Natural Heritage Bureau) This property owned and managed by New Hampshire Audubon.

New Hampshire Audubon is an independent statewide membership organization whose mission is to protect New Hampshire's natural environment for wildlife and for people. It operates nature centers throughout the state that provide educational programs for children and adults. It is also involved in research projects, protects thousands of acres of wildlife habitat, and advocates for sound public policy on conservation issues. For information on New Hampshire Audubon, including membership, volunteering, programs, and publications, call (603) 224-9909 or go to their website at www.nhaudubon.org.

See Audubon's guide to Ponemah Bog Sanctuary.

This brochure was created by the New Hampshire Natural Heritage Bureau as part of a series designed to educate the public about the state’s special plants and natural communities. For more brochures, visit: New Hampshire Natural Heritage Bureau.

NH Division of Forests & Lands - DRED
172 Pembroke Road - PO Box 1856
Concord, NH 03301-1856
Tel: (603) 271-2215
Fax: (603) 271-6488
The DFL is an equal opportunity employer and educator.

This brochure was paid for with funds from the NH Conservation License Plate www.mooseplate.com
  Locator map (map by Ben Kimball for NH Natural Heritage Bureau)

Locator map (map by Ben Kimball for NH Natural Heritage Bureau)

 

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