Appreciating these vital lands
By Bonnie Phillips / ecoRI News staff
“It’s warmer now,” she said. “It’s moving more.”
She had found the salamander in the damp, chilly soil under
a rock in the North Woods at the University of Rhode Island, 225 acres of
forest, wetlands, and streams adjacent to the college campus on Flagg Road.
It was a rainy, cool, late April evening, and the salamander
was sluggish in the cold at first. After spending some time in the 18-year-old
West Greenwich resident’s warm hand, it became more active, scooting around her
palm.
Andrews said it wasn’t her first time holding one of the
creatures.
“These are like the ones in my garden,” she said. “I catch
them all the time in my yard.” Her mother Sandy, standing nearby, laughed and
added, “We live for this.”
The family, including Sandy’s husband Gary, were attending what was expected to be a springtime peeper walk in the woods, led by Michelle Peach, a clinical assistant professor in URI’s Department of Natural Resources Science. It was part of the North Woods Project with URI’s Digital Writing Environments, Location and Localization (DWELL) Labs.
But a collective decision by the peepers, apparently, not to come out that evening instead turned the focus of the discussion on the value of wetlands in the natural world.
Peach, addressing a rapt audience that included students
from nearby schools and members of a 4H club, stood knee-deep in a small pool
wearing waders and brandishing a small net.
“Wetlands benefit people really disproportionate to their
size,” she said. “A big, important thing wetlands give us is they provide
habitat for lots and lots of species.”
Diverse habitat
Wetlands are among the most productive ecosystems in the
world, comparable to rain forests and coral reefs, according to the
Environmental Protection Agency. As Peach pointed out, an immense variety of
species of microbes, plants, insects, amphibians, reptiles, birds, fish, and
mammals can be part of a wetland ecosystem.
Factors including climate, landscape shape, geology, and the
movement and abundance of water determine the types of plants and animals that
inhabit specific wetlands and benefit from their food webs.
Wetlands meet different needs for different creatures,
according to Peach. Green frogs, for example, don’t breed in wetlands. They
eat. “They are here to prey on things,” she said.
“But there are the peepers that we talked about, they will
climb trees. There are wood frogs that are going to be up in trees. Bullfrogs
are going to live in the water almost all the time,” she added.
When it comes to food, wetlands can be a type of biological
supermarket, providing diverse types of meals that attract many animal species.
Dead plant leaves and stems break down in the water to form small particles of
organic material, which feed insects and small fish which, in turn, are food
for reptiles, amphibians, birds, and mammals.
A wetland’s functions and value depend on its complex
relationships with other ecosystems in the watershed — the area where water,
sediment, and dissolved materials drain from higher ground to a shared outlet
such as a stream, lake, aquifer or estuary.
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| Liam Corcoran, a master’s student at the University of Rhode Island, holds a green frog. (Bonnie Phillips/ecoRI News) |
Wetlands are vital to watershed ecology. Their shallow, nutrient-rich waters support organisms at the base of the food web that sustain fish, amphibians, shellfish, and insects. Many birds and mammals also depend on wetlands for food, water and shelter, especially during migration and breeding.
Wetlands’ microbes, plants, and wildlife are part of global
water, nitrogen, and sulfur cycles. Scientists now know wetlands may also help
maintain the atmosphere. By storing carbon in plants and soil instead of
releasing it as carbon dioxide, wetlands help moderate the global climate.
“Wetlands help remove toxins from runoff entering streams,
ponds and groundwater,” Peach said. “Wetlands also are really, really good at
preventing flooding.”
Wetlands act as natural sponges, trapping and slowly
releasing surface water, rain, snowmelt, groundwater, and floodwater. Trees,
root mats, and other wetland plants also slow floodwaters and spread them
across the floodplain. Together, this storage lowers flood peaks and reduces
erosion.
Wetlands in and downstream of urban areas are especially
valuable because they offset the increased runoff from pavement and buildings.
Their water-holding capacity helps control floods and prevent crop
waterlogging.
More than one-third of U.S. threatened and endangered
species live only in wetlands, and nearly half use them at some point in their
lives.
“Anywhere from 25% to 75% of endangered species in the U.S.
rely on wetlands for summer or all of their life,” Peach said. “Globally, 40%
of amphibians are considered endangered.”
Many other plants and animals also depend on wetlands for
survival. Coastal wetlands are essential to estuarine and marine fish,
shellfish, birds, and some mammals. Many commercial and game fish breed and
raise their young in coastal marshes and estuaries. Fish such as menhaden,
flounder, sea trout, spot, croaker, and striped bass, along with shrimp,
oysters, clams, and blue and Dungeness crabs, rely on wetlands for food,
shelter and breeding grounds.
Types of wetlands
Marshes are among the most recognizable freshwater wetlands. Water depth and duration vary: some marshes flood seasonally, while others hold water year-round.
Marshes provide habitat for wildlife, serving as breeding,
nursery, feeding, and resting areas. They also improve water quality by
filtering excess nutrients, sediment, and pollutants from surface water.
Ponds: Rhode Island’s landscape includes hundreds of
freshwater lakes and ponds covering 20,749 acres, according to the Department
of Environmental Management. Whether called ponds, lakes or reservoirs, these
waterbodies offer recreation, important aquatic habitat, and drinking water.
Rivers and streams are common, easily recognized
habitats. Their channels may be wide or narrow, deep or shallow, with sandy,
muddy or rocky bottoms shaped by their origin and the speed and volume of flow.
Rivers and streams connect vegetated wetlands, carrying water and supporting
aquatic wildlife movement.
Vernal pools are shallow waters that fill in
spring or fall with rain or snowmelt. Some are isolated woodland depressions,
while others occur within wetlands such as red maple swamps. Because they lack
a permanent water source, they often dry up by mid-summer.
Their seasonal drying prevents fish populations, creating a
unique habitat and valuable breeding ground for wildlife. In Rhode Island,
spotted salamanders, marbled salamanders, and wood frogs depend on vernal pools
for breeding and survival.
Vernal pools and the species that rely on them are highly
sensitive to urbanization, agriculture and logging. These species need both the
pools for breeding and the surrounding upland habitat for the rest of their
life cycle.
Swamps are the most common wetland type in Rhode
Island. Dominated by trees or shrubs, they occur along rivers and streams, pond
shorelines, in isolated areas, and on hillsides. Because they are not always
obviously wet, they can be hard to identify. Some have surface water in spring
and dry out by summer. Many never flood but have water near or just below the
surface. Their soil may be saturated and mucky, though not always where no
surface water is present.
In the past, swamps had a bad rap, according to Peach.
“Historically, people really didn’t like wetlands. They were
called dismals and mires, all these really negative words, partly because they
are breeding grounds for mosquitoes,” she said.
As a result, some swamps were drained in the past, she
added.
Now, the state has “really good wetland regulations,” Peach
said. “Wetlands are protected in Rhode Island much better than they are in lots
of other places.”
State law includes wetlands protection, with permits
required for development and other activities near freshwater wetlands. DEM and
the Coastal Resources Management Council have jurisdiction over lands near
freshwater wetlands and share standards for wetland buffers based on resource
protection, watershed needs, and existing land use.
Although the spring peepers didn’t make their presence known
during Peach’s discussion, they and other frog species found in Rhode Island, including the
green, northern leopard, wood, pickerel, and gray tree frog and the American
bullfrog, rely on wetlands for survival.
“I just hope [people] leave feeling like wetlands are pretty
amazing,” Peach said. “That’s my goal.”
