On a small farm in Calvert County, soil scientist Gary Jellick measures the water levels in pipe wells scattered across what looks to the untrained eye like a muddy field.
It is actually a fledgling forested wetlands. Now there are only tufts of redtop and green rush grasses growing between pools of water. This spring, Jellick will supervise planting of red maple, sycamore and pin oak trees that grow naturally nearby.
Maryland’s forested wetlands are disappearing faster than any other type, according to state data. Scientists also say forested wetlands are most difficult to create through programs requiring developers to replace wetlands that have been lost.
“It can take 30 years before you get a canopy that comes even close to what you impacted. The forested ones are where you get the controversy,” said Jellick, who works for Coastal Resources, an environmental consulting company that specializes in wetlands creation.
Before developers, state highway agencies or county governments receive a permit to build on wetlands, state law requires that they agree to compensate or “mitigate” for those losses by creating new wetlands.
Regulators used to be concerned primarily with tidal wetlands, which develop alongside streams and the Chesapeake Bay. Over the years, their efforts have reduced those wetlands losses to almost zero.
“The battle ground has moved from the marsh type of environment to these wooded areas that may only be wet one month out of the year,” said Jellick.
State data show forested wetlands, prized for their ability to purify water and provide natural habitat, account for almost half the 150 acres of wetlands on which the Department of Environment authorized construction from 1991 to 1995.
Forested wetlands are also tricky to create and monitor, scientists say. Trees can take years to mature and water sources that feed a nontidal wetlands ecosystem — unlike the dependable tides of the Chesapeake Bay — can be unreliable.
For these reasons, state regulations require creating two acres of forested wetlands for every one lost.
But scientists differ on whether humans and bulldozers can successfully replace natural wetlands that have evolved for thousands of years.
“I think it’s inappropriate to use the s-word. Success,” said Mary E. Kentula, a wetlands ecologist for the Environmental Protection Agency who has studied wetlands mitigation projects nationwide.
During the 1980s, when state and federal governments began looking for ways to stem wetlands losses, many mitigation projects across the nation were considered failures.
Some were too dry to qualify as true wetlands, and others turned out to be ponds with standing water that drowned all the plants. Some improvements have been made, as wetlands managers and regulatory agencies have learned along the way.
“I think it has gotten better,” said Bill Street, a wetlands scientist with the Chesapeake Bay Foundation. “Now whether we’ve gotten it down to a science, I don’t think so.”
So far, the Department of Environment has not deemed any of its mitigation sites outright failures, which would require developers to start over at costs ranging from $10,000 to $100,000 an acre.
But none of the sites has reached the end of the state’s monitoring period. The Department of Environment requires companies to provide reports for five years, demonstrating there is enough water present and that plants are surviving.
“We have some sites that looked excellent from the start, some look like they’re going to make it, and others are kind of questionable,” said David Walbeck of the Maryland Nontidal Wetlands and Waterways Office.
Determining whether a wetlands mitigation project is working depends largely on the criteria of success. Just because an area has enough water and plants does not necessarily mean it is functioning like the natural wetlands it replaced.
“Taking a few water measurements and seeing whether it’s green is cheap and easy. If you want to ask the hard questions about whether you have water quality or habitat, it’s much more expensive,” Kentula said.
Matthew Perry, a habitat management scientist with the Patuxent Wildlife Research Center, has studied six constructed forested wetlands across the state.
Perry found that although there was plenty of vegetation, there was a high mortality rate and slow growth among trees that were planted from nurseries.
“In four years, a lot of these sites don’t look any more forested than when we started. In the fifth year, I don’t think there’s going to be a major change,” Perry said.
In Calvert County, Jellick hopes that one day his muddy field will resemble the tangled forested wetlands seeping with black water nearby. So far things look promising, but the wetlands is just beginning to emerge. “At this point, everybody is pretty happy if you can just create a wetlands environment and have it stay wet,” Jellick said. -30-