State wildlife officials Wednesday ruled that the California tiger salamander deserves protection as a threatened species, a move that adds another administrative layer to scrutiny over development projects in the amphibian's habitat.

Federal law already protects salamander habitat at the higher, endangered level, and the state's new designation is expected to mean state permits will also be required.

"As far as we are concerned, it does not change very much in terms of regulatory obligations," said Sonoma County's planning director Pete Parkinson. "There may be additional permitting work that an applicant has to do for the state Fish and Game Department, but it won't be substantial if they already have to satisfy the federal Endangered Species Act."

In Sonoma County, a 74,000-acre expanse of the Santa Rosa Plain is being eyed as critical habitat under the federal law. A federal decision on how much of plain, from Windsor Creek to northern Petaluma and from Highway 116 to Petaluma Hill Road, will be included is due by July 1, 2011.

The California Fish and Game Commission's decision affects about 400,000 acres of the amphibian's habitat from from Yolo County north of Sacramento to Santa Barbara County. The commission has twice denied listing the salamander, but a 2004 lawsuit filed by the Center for Biological Diversity resulted in a state appellate court order that the Fish and Game Department reconsider the issue.

The center, based in Arizona, welcomed the decision. Center spokesman Brian Nowicki said 95 percent of the tiger salamander habitat in Sonoma County "is threatened by development."

The 3-2 commission vote came over the objections of the wine industry, business groups and homebuilders, which complained scientists were unable to show accurate population counts for the salamander and had exaggerated how much rural land might be developed in the future.