RAMONA —— A non-profit wildlife group has purchased 230 acres of grasslands, thwarting future development and increasing the size of a growing nature preserve.

The Nature Conservancy of California announced Friday that it has secured $1.6 million in state funds to buy the land, which lies next to Oak Country Estates.

The wildlife group also purchased 420 acres there in June 2003 as part of a plan to protect 8,000 acres of grasslands habitat west of Ramona.

"What's important about these properties is it provides a habitat for many wildlife out there," said project Manager Chris Basilevac.

The land encompasses vernal pools, coastal sage scrub and oak woodlands, Basilevac said. It's home to bobcats, hawks and golden eagles, as well as endangered species such as Stephens' kangaroo rat and San Diego fairy shrimp.

Basilevac said the land is also an important wildlife corridor for San Diego County, connecting Poway to Palomar Mountain.

"That's always important for not only ensuring a safe migratory path, but also ensuring genetic diversity," he said.

The Santa Maria Creek runs through both properties. Basilevac said forbidding development on the floodplain will help restore stream banks. When stream banks erode, soil is dumped into the water and kills plants and fish. The Santa Maria Creek flows into the San Dieguito River, which feeds Lake Hodges, a drinking water source for the county. Basilevac said the new land protection will keep contaminants out of the water supply.

The Nature Conservancy will work with the county parks department and the non-profit Wildlife Research Institute to restore the creek. Manmade restoration typically involves planting trees, grasses and shrubs for erosion control, Basilevac said.

Proposition 13, a water-protection initiative that voters passed in 2000, created the Flood Protection Corridor Program. That program empowered the state's Department of Water Resources to finance the land deal because of the wildlife group's flood-protection work.

Basilevac said an additional threat to the land is non-native vegetation. Foreign weeds and grasses, which are typically introduced by humans, harm other species and stifle diversity, he said. The unlikely heroes are cattle, he said, which graze on the vegetation. The Nature Conservancy is in the early stages of an agreement with local ranchers that would give the group some control over the animals.

"It allows us to work with the ranchers and say, 'Hey, we need the cattle to go over to this area and munch,' " Basilevac said.

Basilevac said landowners have been very supportive of The Nature Conservancy.

"A lot of people care about the environment out there. They like to see the wildlife," he said. "I think it's the reason a lot of them moved out there."