A group of about 70 county park employees picked up shears and shovels recently to spend a day helping remove some of the nonnative vines that are invading parks and forests in Montgomery County.

It was the first time that a county park manager dedicated an entire staff to work on the problem, said Carole Bergmann, forest ecologist for the Maryland-National Capital Park and Planning Commission. The workers concentrated on a part of Kensington Parkway Stream Valley Park between Bexhill Drive and Littledale Road, focusing on removing porcelainberry, a vine native to China and Japan.

Bergmann said the spreading vines, which kill trees by strangling trunks and smothering the canopy, can cause serious ecological changes. They also crowd out other native plants.

In coming years, Bergmann said she hopes county officials designate some money in the budget to hire staff to deal with the problem. Bergmann has mobilized a volunteer group of Weed Warriors, about 300 residents who regularly work to remove the invasive vines from the county's park system.

Above, from left, Leon Maiden, Holly Thomas and Corie Jones clear porcelainberry vines from Kensington Parkway Stream Valley Park. At left, William Powell hauls away the vines, which strangle tree trunks and smother the canopy. A volunteer removes porcelainberry vines, which aren't native to the county.