|Mineral Soil Wetlands
Headwater wetlands are temporarily to seasonally flooded wetlands located at the origins of streams. Headwater wetlands have a hydroperiod that is characterized by predictable flooding associated with spring runoff and sporadic flooding associated with localized storm events. Headwater wetlands tend to be discharge wetlands where soil water and groundwater surface to become the origin of streams. Thus, these systems are hydrologically open and soluble inorganic material in groundwater plus soluble organic material in surface outflow are flushed causing headwater wetlands to be less acidic and more fertile than bogs and fens. The hydroperiod for headwater wetlands shows spring time flooding as well as additional frequent flooding associated with even small local storms.
Common vegetation in headwater wetlands includes red maple, black gum, sweet gum, ash, swamp white oak, loblolly pine, nettles, and jewelweed.
Wildlife inhabiting the headwater wetlands include spring salamander, wood turtle, water shrew, common merganser, northern dusky sala? mander, two?lined salamander, beaver and moose and neotropical birds such as the Louisiana waterthrush and mourning warbler.
Landings and equipment storage areas should be kept out of headwater wetlands due to the frequent, unpredictable flooding common to these wetlands. Open hydrologic conditions mean extra care since pollutants introduced here can quickly affect downstream environments.
Streamside wetlands may be narrow in upland areas and expand somewhat as the valleys widen along larger streams. Because these wetlands are associated with streams having larger watersheds, the hydroperiod has a more predictable pattern in which flooding is closely associated with spring thaw and larger, more regionalized storm events. Hydrographs for streamside wetlands also show some delay between storm events and peak flows due to the distance from the headwaters. Like headwater wetlands, streamside wetlands are hydrologically open.
While flooding is somewhat more predictable in streamside wetlands than in headwater wetlands, they are still subject to occasional unexpected flooding. This, along with the relatively small area involved, makes it prudent to locate landings and equipment storage areas outside of these wetlands. When it is absolutely necessary for haul roads and skid trails to be located in the wetland, they must be designed so as not to impede the natural hydrology including the inflow and outflow of flood waters.
Wooded swamps include broad bottomland forests in the floodplains of large rivers with very large watersheds. As a result, the hydroperiod shows a very predictable pattern in which flooding is associated only with spring thaw and prolonged, regional storm events. Hydrographs for wooded swamps show greater delay between storm events and peak flows due to the remoteness of their headwaters. Wooded swamps are also hydrologically open and dependent, to a degree, on floodwaters for the delivery of nutrient laden silts affecting their fertility.
Vegetation includes ostrich fern, royal fern, cinnamon fern, Canada mayflower, goldthread, starry false Solomon's seal, nodding trillium, American false-hellebore, lizard's tail, skunk cabbage, red maple, bald cypress, pin oak, swamp white oak, swamp chestnut oak, overcup oak, willow oak, cherrybark oak, black gum, water tupelo, swamp tupelo, cottonwood, sycamore, loblolly pine and Atlantic white cedar.
Wooded swamps provide habitat for wood duck, hooded merganser, spotted turtle, star-nosed mole, mink, raccoon, water snake, ribbon snake, wood frog, spring peeper, gray treefrog, spotted salamander, great blue heron, green heron, barred owl and neotropical birds such as the northern waterthrush, common yellowthroat, blue-gray gnat-catcher and American redstart.
Spring seeps are broad shallow flows that occur where groundwater emerges on sloping terrain usually on the lower slopes of hillsides and mountains. They are discharging wetlands in these situations and can be the source of small streams. However, they may also percolate back into the groundwater becoming recharging wetlands.
Spring seeps are valuable to wildlife, particularly wild turkey, in severe winters because the emerging groundwater provides snow free feeding sites in winter and are among the first sites to provide green plants in spring.
Spring seeps are used by amphibians such as the northern dusky salamander, spring salamander and by neotropical birds such as the worm eating warbler, veery and wood thrush.
Plants to look for include moist site tree species, skunk cabbage, sedges, water cress, marsh marigold, goldthread, wintergreen and sensitive fern.
Where possible, haul roads and skid trails should be routed above the seep at a distance sufficient to avoid disturbing the flow. When roads or trails must pass below the seep they should pass at a point beyond where the seep has reentered the ground or where a defined channel permits an environmentally acceptable crossing such as a culvert.
Beaver respond to an instinct to impound flowing water. Consequently, beaver ponds usually expand and alter existing streamside wetlands. However, beaver also create ponds and wetlands where none would otherwise exist. Beaver pond ecosystems have their own life cycle.
Trees and other vegetation are killed by the prolonged high water levels until little more than grasses and forbs remain. In time, the beaver's food supply will be depleted resulting in abandonment of the dam, lowering of the water table and a return to forest through plant succession. Once forested, the cycle starts over with beaver reestablishment. The hydrology of the wetland created by a beaver dam reflects the hydrology of the setting in which it is built. If the beaver dam is built in a headwater setting, the hydrology will be similar to that of a headwater wetland.
Many forest plants and animals depend on the site at different stages in the cycle. Snags, large old dead trees, left in the pond from the forest cycle provide preferred nesting sites for herons and nesting cavity species. Hence both forest and pond cycles are necessary to sustain this habitat. Plants typical of beaver pond wetlands include pondweed, arrowhead, cattail, smartweed, alder, red maple, aspen, manna grass, rice cutgrass, bulrushes and sedges.
Wildlife species using beaver dam wetlands include beaver, great blue heron, green heron, red spotted newt, green frog, bullfrog, wood duck, black duck, hooded merganser, snapping turtle, water snake, ribbon snake, star nosed mole, mink, otter, moose, tree swallow, raccoon, spring peeper, gray treefrog, bullfrog. Neotropical birds such as the prothonatory warbler, Philadelphia vireo, tree swallow and ruby crowned kinglet also use beaver ponds.
Regulatory requirements vary from state to state. Check with your state fish and game department before disturbing a beaver pond. Bridging the narrow stream below the dam may be the best alternative for crossing drainages with beaver dams.
Vernal ponds are small ponds that are most obvious in the forest during the spring of the year. Although some vernal ponds may not meet the statutory definition of wetlands, they will be addressed here because the subject comes up whenever wetland forest management is discussed.
The ponds derive their name from vernalis, the Latin word for spring, because they result from various combinations of snowmelt, precipitation and high water tables associated with the spring season. The ponds tend to occur in small depressions and while many dry up in late summer, a few have water year round. The ponds vary greatly in terms of recharge, discharge characteristics, source of water and geology. Those supplied by groundwater from limestone geology tend to be less acid and less variable in acidity. By definition, vernal ponds are free of fish and can, therefore, support a rich community of amphibians and invertebrates that would be difficult to sustain if fish were present.
Typical pond users include salamanders such as the marbled salamander which migrates from burrows in the forest floor to the pond basin with the onset of fall rains. The males leave sperm sacks to be used by the females to fertilize the eggs which are deposited under rocks and leaves on the pond bottom. The adults then return to the forest and as the fall rains fill the pond the eggs hatch and the larvae feed on the invertebrate life of the pond. The Jefferson salamander migrates over the snow on rainy nights in late winter to slip into the pond through cracks in the ice. After mating, the females attach their egg masses to small twigs under water. The spotted salamander arrives after the Jefferson and similarly deposits egg masses on twigs under the water.
These species are followed in turn by wood frogs, spring peepers, spadefoot toads, gray tree frogs, American toads and other amphibians who depend on the pond habitat for reproduction. The developing amphibians prey on fairy shrimp, copepods, daphnia, phantom midge larvae, and mosquito larvae and, in turn, are preyed upon by insect predators such as diving beetles, backswimmers and fishflies (Cassell 1993). Neotropical birds such as the worm eating warbler, veery and wood thrush also use the vernal pond area.
The ponds typically occur under the forest canopy with the pond basin relatively free of vegetation. Thinning of the canopy can result in accelerated evaporation rates shortening the duration of pond flooding and dehydrating the larvae before development is complete. Increased exposure to sunlight
Deep tire ruts in the vicinity of the pond are also a problem. They can be a physical trap for young sala manders and turtles not developed enough to climb out of them. The ruts can also be mistaken for the pond destination by adults who deposit egg masses in the ruts. In both cases, the young will probably be eaten by predators or die of dehydration because the ruts usually dry out before the vernal ponds.
The ponds are easily recognized in early spring when they are filled with water and this is the best time to establish their location. In summer they are more difficult to recognize, but some indicators are blackened and compressed leaf litter, buttressed tree trunks, water marked tree trunks, and the presence of vegetation such as red maple, highbush blueberry and buttonbush.
Management plans should call for marking the location of vernal ponds and any necessary protective zones in the spring when the ponds are filled with water.
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