Stephen P. Broker
SLIDES OF CONNECTICUT’S FRESHWATER WETLANDS.
I have made a series of trips to photograph each of the six wetland habitats described in this unit, selecting the most representative slides depicting the habitats and their bedrock geology, vegetation, wildlife and dynamic processes. Each section below has a brief description of the slides, followed by a set of questions concerning the pattern and process of wetland ecology at the site. These are intended to encourage the student to observe and describe, ask original questions, develop explanations, communicate ideas to others, and apply knowledge to new problems. I can make available more detailed descriptions of these slides than can be presented here.
WEST ROCK RIDGE VERNAL POOL, HAMDEN, CONNECTICUT.
(1,2) West Rock Ridge and Konold’s Pond: the west-facing cliffs and talus slope. View is toward Sleeping Giant State Park. (3,4) West Rock Ridge ridgetop vernal pool, January 1995. The pool is unfrozen, snow dusts surrounding upland. Vernal pool in mid-February 1995. Ice and snow cover the pool, making it indistinguishable from surrounding upland. (5-8) Vernal pool in early March 1995. Snow has melted on upland, but pool is completely ice-covered. Pool in late April 1995, at near-maximum size and depth. (9) Leaves and sticks on bottom: substrate for Spotted Salamander spermatophores. (10) Mass of Wood Frog eggs in vernal pool, late April 1995. (11) Wood Frog tadpole in hand, late April 1995. (12) Spotted Salamander (
Ambystoma maculatum
) from West Rock Ridge ridgetop vernal pool. (13,14) Spotted Salamander egg masses in vernal pool, late April 1995. (15) Vernal pool in late July, now completely dried up and difficult to recognize as wetland habitat.
Questions: How can a wetland form on top of a high ridge? How does this wetland change from one season to the next? What’s the source of energy for all the animals living in this pool? How is the life cycle of the Wood Frog or Spotted Salamander matched to this temporary wetland? How would you go about studying small pool organisms?
DURHAM MEADOWS RED MAPLE-GREEN ASH-TUSSOCK SEDGE SWAMP, DURHAM, CONNECTICUT.
(1,2) Durham Meadows and the Coginchaug River, January 1995. Leafless trees and brown tussock sedges. Durham Meadows and the Coginchaug River, Spring 1994. Broad-leaved trees now leafed out. (3) Southern portion of Durham Meadows. Red Maples, tussock sedges, and emergent vegetation. (4) Coginchaug River with dense growth of Wild Rice grass (
Zizania aquatica
) and red maples (
Acer rubrum
) and green ash (
Fraxinus
pennsylvanica
). Photo taken further north into the wetland than previous photographs. (5) Common Cattail (
Typha
latifolia
.) marsh in gaps in the red maple-green ash stand. (6,7) Red maple-green ash swamp with floating and emergent aguatic vegetation. (8) Close-up of green ash. (9) Coginchaug River with emergent aquatic vegetation. (10) Cinnamon Fern (
Osmunda cinnamomea
) with brown sporebearing fronds. (11) Cowslip (
Caltha palustris
), a spring-flowering plant of streambanks and swamps. (12) Yellow Flag (
Iris pseudacorus
), an exotic escapee. (13) Slender Blue Flag (
Iris
prismatica
), native to wet meadows and marshes of the northeast. Fronds of Sensitive Fern (
Onoclea sensibilis
) in the background. (14) Arrow Arum (
Peltandra virginica
), an abundant emergent plant of shallow streams. A member of the Arum Family (
Araceae
). (15) Violet (
Viola sp.
) growing on windthrow mound. (16) Whitetail Dragonfly male (
Libellula lydia
), common to shallow rivers and freshwater ponds. Males are fiercely territorial and guard mates aggressively. (17) Green Frog (
Rana clamitans
). They feed on beetles, flies and spiders. (18) Common Snapping Turtle (
Chelydra
serpentina
), largest freshwater turtle in New England. This one was found on the banks of the Coginchaug River. It had a snub-tail, bitten off during combat with another male or when it was much younger. Snapping turtles prefer lakes, rivers, backwaters with muddy or peaty bottoms. (19) Nest of Red-winged Blackbird (
Agelaius
phoeniceus
) with two eggs and two freshly hatched nestlings. (20,21) Virginia Rail (
Rallus limicola
) parent (#20) in immediate vicinity of nest (#21). The five year Connecticut Breeding Bird Atlas lists only 12 atlas blocks in the state with confirmed breeding of Virginia Rail. (22) Beaver (
Castor canadensis
) dam in Coginchaug River. This mammal has considerable influence on the Durham Meadows wetland system. (23) Muskrat (
Ondatra zibethicus
) house deep in Durham Meadows. (24) Plowed agricultural land bordering Durham Meadows.
Questions: How is this wetland different (similar to) a vernal pool? Identify a floating plant, an emergent plant, a shrub and a tree from this wetland, and describe how it is adapted to the wetland environment. How do the flowering plants get pollinated here? What predators live here? What is their food? What effect does the beaver have on this wetland? How does nearby farmiand affect marsh life?
CONNECTICUT RIVER SILVER MAPLE FLOODPLAIN FOREST, ROCKY HILL, CONNECTICUT.
(1,2) The Connecticut River at Rocky Hill, with surrounding floodplain forest. Banks of the Connecticut River. (3-7) Back channels of the Connecticut River. Note trees arching into the back channels from each side. (8) Dead Man’s Fingers fungus growing in broken limb of Silver Maple. (9) Royal Fern (
Osmunda regalis
), a tall fern of wooded swamps and moist woodlands. (10) Wood Nettle (
Laportea canadensis
), an herbaceous plant of bottomiand hardwood forests and floodplains. (11) Garlic Mustard (
Alliaria officinalis
), a spring-to-early summer flowering plant of open woods. (12) Poison Ivy (
Rhus radicans
) vine of considerable diameter and age. (13) Boxelder (Aser negundo), common understory tree of floodplain forests and streambanks. A short-lived, fast-growing tree easily damaged in storms or floods. (14) Flood damage to Silver Maples along Connecticut River back channel. (15) Dry back channel immediately adjacent to the Connecticut River. (16,17) Common Snapping Turtle from back channel (slide #15).
Questions: To what extent does change affect this site? What is the topography (surface features) of the site? Is there any evidence of serious floods? Is there evidence of channel migration? Describe the soil found here. How well can this site store water which overflows the river channel during floods? Do the trees grow in zones between river and surrounding farmiand? What advantage do vines have this habitat? Are there any young trees growing up here? What are the main predatory animals living here? How has human activity altered the floodplain? What is the range of human activity at this site?
MOHAWK STATE FOREST BLACK SPRUCE BOG, CORNWALL, CONNECTICUT.
(1) Connecticut’s hilly Western Highlands, from Mohawk Mountain. (2) Boardwalk entering Black Spruce Bog, Mohawk State Forest. (3) University of New Haven graduate students studying bog ecology. (4,5) Eastern Hemlock (
Tsuga canadensis
) trees. Dense ground cover of Cinnamon Fern (
Osmunda cinnamomea
). (6,7) Sphagnum moss (
Sphagnum sp
.) ground cover in black spruce bog. Close-up of sphagnum moss. (8,9) Windthrow hemlocks and Black Spruce (Picea mariana), blown down by the tornado of July 10, 1989. Windthrow mound, which creates uneven topography of a black spruce bog. (10,11) Canada Mayflower (
Maianthemum canadense
), a common, low-growing white-flowering plant of bog margins. Starflower (
Trientalis borealis
), an abundant spring-flowering plant. (12,13) Carnivorous plants of the black spruce bog. Round-leaved Sundew (
Drosera rotundifolia
), whose leaves contain a sunburst of hairs with sticky drops at the tips. Pitcher Plant (
Sarracenia
purpurea
), a plant with pitcher-shaped leaves which attract and capture small to large insect prey. (14-16) Close-up of Black Spruce tree, the species for which these northern wetlands are named. Eastern White Pine (
Pinus Strobus
). Tamarack, Eastern Larch (
Larix
laricina
), a deciduous conifer of the bog. (17) Red Maple (
Acer
rubrum
), the deciduous tree species which threatens the long-term growth of Black Spruce. (18) Limestone outcrop adjacent to the bog, an indication of the proximity of the northern Limestone Valley of northwestern Connecticut.
Questions: How is the climate of northwestern Connecticut different from New Haven’s climate? What types of weather will have greatest impact on this wetland? How have bog plants adapted to living in an environment where the soil is very poor in minerals and nutrients? What are the difficulties faced by the trees growing in this bog? In what ways is this wetland different from the Conn. River floodplain?
CALCAREOUS RED MAPLE-BLACK ASH-AMERICAN ELM SWAMP, SOUTH CANAAN. CONNECTICUT.
(1,2) Calcareous swamp of Northwestern Connecticut. These red maple, black ash (
Fraxinus
nigra
) and American elm trees grow above a limestone bedrock in a highly alkaline soil. (3) Red Maple (
Acer rubrum
) saplings showing regeneration of the forest overstory, and herbaceous wetland plants. (4,5) Close-up of American Elm (
Ulmus americana
). Stand of Red Maple trees prior to their leafing out. (6) Ground cover of ferns and grasses. (7-9) Tussock sedges and pooled water of the calcareous swamp. Skunk Cabbage (
Symplocarpus foetidus
) and tussock sedges (
Carex sp.
) of the swamp. Violet (Yiola sp.) in flower. (10) Spreading Globeflower (
Trollius laxus
), a rare and local spring-flowering plant of swamps and moist soils. (11) Yellow Lady’s Slipper (
Cypripedium
calceolus
), a late-spring flowering orchid of alkaline swamps (12) Quarry building where limestone chips are prepared for commercial use. Mineral extraction is an important Conn. industry.
Questions: Why are many acid-loving plants unable to grow in this wetland? How does the bedrock found below these wetland plants affect the types of plants growing here? What does it mean to be an “endangered species”? What sorts of animals live in Robbins Swamp? Why are sites such as this often drained for human purposes? How would you protect a site such as this from development?
ATLANTIC WHITE CEDAR SWAMP, NEW LONDON COUNTY, CONNECTICUT.
(Photographs are from the Atlantic White Cedar Swamp in South Wellfleet, Massachusetts, accessible by an interpretive trail and boardwalk of the Cape Cod National Seashore.) (1,2) Entrance to the Atlantic White Cedar Swamp. Atlantic White Cedar (
Chamaecyparis thyoides
) trees on either side of the boardwalk in the heart of the cedar swamp. (3) Sphagnum Moss (
Sphagnum sp
.), the predominant ground cover of the cedar swamp. (4) Inkberry (
Ilex alabra
), a swamp-loving shrub of the Holly Family. (5) Highbush Blueberry (
Vaccinium corymbosum
), a common cedar swamp shrub which produces tasty berries for wildlife and humans. (6-9) Atlantic White Cedar trees. Medium-aged dense tree growth. Older cedar trees of the swamp. Close-up of Atlantic White Cedar bark. This tree is resistant to fire, and it is the source of weather-resistant and rot-resistant cedar shingles. One of the few young, regenerating Atlantic White Cedar trees in this cedar swamp. (10,11) The Atlantic White Cedar canopy. Tall Red Maple trees (
Acer
rubrum
) grow up into gaps in the canopy.
Questions: Where do white cedar swamps tend to form? What are the most common plants here? In what ways are animals adapted for life in the swamp? Why do these wetlands depend on disturbance?
Lesson Plan #2
IDENTIFYING WETLAND PLANTS.
Numerous field guides are available for use in identifying herbaceous and woody wetland plants (see bibliographies below). The teacher can locate a nearby wetland and collect cuttings from approximately 20 different plants for identifications. Field guides make use of a dichotomous key for identifications, use flower color to refer the reader to the correct guide pages, or use a key based on flower type, plant type and leaf type. I have students collect the following information on identified plants: common name, scientific name (genus and species), plant family, preferred habitat, flowering time, page references (from one or more guides), and any notes which are important for understanding how the plant grows in a wetland environment. Ten to fifteen plants are set out in clearly marked stations, and each pair of students has a specified period of time—often five minutes—to make an identification. At the end of this time period, they are instructed to move on to the next station and try to make identification of the plant there. This enables each pair to see and study a number of plants in a class period. The laboratory activity is completed with a run-through of all plants for their identifications by students.
Lesson Plan #3
INVENTORYING INVERTEBRATE LIFE IN A VERNAL POOL.
Collect a small sample of dead leaves and detritus from the bottom of a vernal pool, and spread the collected material out in a plastic or metal tray. Have students gently probe through the leaf matter to locate any associated invertebrate life. Leaf samples can be made over a period of months, from January through May. The crustaceans (including fairy shrimp), isopods, water mites, mosquitoes, dragonfly nymphs, caddisfly larvae, beetles and bugs, midges, clams and snails can be identified, at least to family level, using one of several guides to aquatic arthropods that are available. Students can attempt to keep invertebrates alive in the classroom, using small fish tanks or other glass containers.
