Two Sierra Nevada environmental groups have settled lawsuits challenging the rezoning of 12,541 acres of timberland owned by Sierra Pacific Industries, the largest private landowner in California.

The settlements announced Friday rescind actions in Sierra and Lassen counties that would have changed forests from timberland production zones to those that eventually would allow residential development.

"We're pleased with this decision because it puts the brakes on the unnecessary loss of California forestlands," said Laurie Davis, president of Friends of Lassen Forest, which filed the lawsuit in August.

The zoning change would have affected nearly 5,500 acres that include the headwaters of several sensitive streams, the spawning grounds for the Eagle Lake trout and land next to a U.S. Forest Service wilderness area.

In Sierra County, the settlement reached with High Sierra Rural Alliance affects 7,083 acres along Henness Pass Road in a remote and environmentally sensitive area within the checkerboard of Tahoe National Forest.

"It doesn't make sense to convert remote forested lands for development in view of the environmental challenges we are facing due to climate change and the critical role forests play in enhancing watershed and habitat health," said Stevee Duber, a spokeswoman for the environmental alliance that filed the lawsuit in July.

Sierra and Lassen counties are among eight Northern California counties where the Anderson-based timber company had sought to remove a total of about 40,000 acres of its forests from timber production zoning. New zoning designations would start a 10-year countdown that would end the tax benefits Sierra Pacific has enjoyed under timberland production zoning, approved by the Legislature in 1976 to encourage long-term working forests.

After 10 years, the company could request new zoning designations that permit development.

With the settlements in Sierra and Lassen counties, only Tehama and Shasta counties have authorized the company's rezone requests on a combined 6,339 acres.

Sierra Pacific recently withdrew applications for rezoning 34,237 acres of timberlands in Butte, Lassen, Plumas, Sierra, Siskiyou and Trinity counties, said Mark Pawlicki, a company spokesman. The requests ranged from 7,826 acres in Plumas County to 2,537 acres in Tehama County.

Although it has no plans for development, the company is not abandoning zoning changes on some of its 1.7 million acres, Pawlicki said.

Instead of a piecemeal approach, company officials want to take a more comprehensive view that adheres to the legal processes required by state environmental laws, he said.

"It's the same way we look at timber harvests and wildlife – by compiling cumulative-effects analyses," Pawlicki said.

In addition to lawsuits in Sierra and Lassen counties, the company's zoning-change requests drew comments from state Attorney General Jerry Brown.

Rezoning 3,846 acres in Siskiyou County on the southern slopes of Mount Shasta could affect hundreds of important Sierra species, including spotted owl, fisher and pine marten, Brown said in a Nov. 3 letter to Ruth E. LaTourelle, county assistant planner.

The potential loss of forested land also would contribute to increased greenhouse gases, he wrote.

Brown's four-page letter challenged the county's conclusion that the zoning change would have no potential to cause significant impacts to the environment.

The High Sierra Rural Alliance and Friends of Lassen Forest lawsuits raised similar challenges and disputed the counties' claim that the rezoning was exempt from the California Environmental Quality Act. Both lawsuits charged that the supervisors' actions violated the counties' general plans as well as a specific plan for the Eagle Lake area in Lassen County.

Sierra Pacific has agreed to cover the court costs of the two environmental groups.