Prescribed Burn and Fill Removal Restores Bog Turtle Wetland
Top, Prescribed burn being conducted as part of bog turtle habitat restoration. Bottom, Post-burn, grassy hummocks provide excellent habitat for bog turtles. Inset: Bog turtle. All photos, USFWS.
The bog turtle (Clemmys muhlenbergii), a federally threatened species is known to occur in Cecil, Harford, Baltimore, and Carroll counties of Maryland. The primary threat to bog turtles is the loss of the unique wetlands on which they depend. These are saturated, spring fed wetlands such as bogs and wet meadows with soft muddy areas. Development, shifts in land use, succession by woody shrubs and trees and invasive plants contribute to loss of bog turtle habitat.
Since more than 97% of this habitat occurs on private lands, recovery of the bog turtle depends on private landowners joining the recovery effort. One particular wetland on a privately-owned site in Harford County has supported bog turtles for over 30 years. Bog turtles were first discovered at this site in 1977 by Maryland Department of Natural Resources.
But over the years the original wetland had been altered. A previous landowner built a pond right next to the wetland. Fill from this pond was deposited into the wetland to create a crossing for farm equipment, altering the flow of water and encouraging the excessive growth of woody plants on the drier, elevated ground.
The bog turtles have been confined mostly to a small man-made drainage ditch that runs the length of the wetland. In order to increase the bog turtle habitat, a burn was conducted in late February 2012 to remove excessive woody vegetation at the site, exposing grassy hummocks more suitable for the turtles. Then the fill was removed until the elevation of the area was sufficient to re-establish hydrology to the altered part of the wetland. Removed fill was then placed in a nearby agriculture field.
To prevent harm to the bog turtles, a low ground pressure bulldozer was used to remove the fill. Both the burn and the fill removal was done while the turtles were still hibernating and not basking and traveling around. The area was also searched for any bog turtles prior to the work so that any turtles found could be moved to the drainage ditch. Silt fences were placed between the upland area and the adjacent wetland to prevent any turtles from moving into the work area from the wetland.
After the work was completed the site was monitored twice a month to evaluate hydrology and vegetation. With the fill removed, hydrology being re-established, and native plants now covering the wetland, the bog is providing excellent habitat for the bog turtles. Surveys conducted in the wetland in May 2012 resulted in 35 turtles being found; 13 males, 17 females, and 5 juveniles.
This project is the first wetland restoration project to be conducted for bog turtles in Maryland. It was done in partnership with the Maryland DNR, Natural Heritage Program and a very cooperative landowner. It required careful planning and conservation measures had to be established and implemented to avoid any negative impacts to bog turtles.