GRANTS PASS, Ore. — A watchdog group is challenging the environmentally friendly “green lumber” certification for Plum Creek Timberlands, one of the nation’s biggest landowners and timber producers. Plum Creek owns roughly 865,000 acres of timberland in Maine.

The Center for Sustainable Economy, based in Lake Oswego, Oregon, filed the complaint Thursday with a nonprofit group that verifies whether timber producers follow standards for environmentally responsible logging.

The complaint covers Plum Creek logging in Oregon’s Coast Range, citing 11 civil citations over the past six years for violating state logging regulations, including four limiting the size and placement of clearcuts.

It demands that the nonprofit Sustainable Forestry Initiative immediately suspend certification for Plum Creek in Oregon, and investigate the company’s logging practices throughout the country.

“We are aware of the complaint that’s been filed and we’re reviewing it,” said Kate Tate, Plum Creek’s spokesperson in Seattle, where the company is headquartered. “Plum Creek is committed to practicing sustainable forestry wherever we operate, including in Maine. There is an established process in place through SFI Inc. and we will engage fully in SFI’s process to understand and address the complaint.”

Plum Creek has SFI certification for its forestry practices across the country, including in Maine.

The development company came to Maine in 1998 when it bought timberlands in six counties held by SAPPI. It has placed more than 428,000 acres of forestland into conservation since.

In addition to managing forests for timber production, the company also has developed land for recreation purposes.

— Staff Writer Whit Richardson contributed to this report.