SMART officials Wednesday reiterated their promise to hold off on cutting down a rare chimera redwood tree in Cotati until they can explore other options, while activists working to save the tree pressed their case for its value.

At a board meeting in Petaluma for Sonoma-Marin Area Rail Transit, several speakers urged the board to save the unusual green-and-white coast redwood or at least consider allowing it to be transplanted so it can be studied and enjoyed.

SMART General Manager Farhad Mansourian re-emphasized the agency's commitment to postpone construction orders that would lead to the removal of the 52-foot tree along the tracks at East Cotati Avenue.

"The science in this area does not appear to be exact. Because of that, we're taking our time ... until we figure out what is the right thing to do," he said. "SMART is a community project. We are part of the community. The last thing we want to do is just come in and tear trees down or destroy neighborhoods."

The tree has become a cause c??re since arborists who study rare chlorophyll-deficient redwoods publicized its presence in Cotati earlier this month. The unusual tree stands alone between a block wall and the railroad tracks.

SMART, which plans to begin running commuter train service in a couple of years, had targeted the tree for removal because of its proximity to where a second, passing track is planned just north of the Cotati station.

SMART officials said their analysis shows construction would damage the tree and destabilize it, making it a fall hazard in wind. It would also be too close to the planned tracks to meet federal safety guidelines.

The tree, which neighbors say has been there since at least 1947, is one of only 10 known coast redwoods that exhibit green and white foliage on the same branch, say arborists who specialize in that field. A chimera is a subset of an albino redwood that exhibits traits of albinism while also showing normal green foliage.

An arborist hired by SMART said he believed the tree to be more common, though still rare.

Tom Stapleton, an arborist who used to live in Sonoma County and who now works in Amador County, tried to explain the tree's scientific value to the SMART board, which includes elected officials from Sonoma and Marin counties.

He said the arborist's report SMART relied on to conclude it should be cut down "doesn't truly assess how rare that tree is."

"The information that's contained in this tree is priceless," said Mari Mack, a Marin County woman who attended Wednesday's meeting.

Two SMART representatives outlined engineering or construction hurdles that could be encountered in an effort to save the tree in its current location. Digging out the tree for transplanting may cause problems for the adjacent block wall, Mansourian said.

Mansourian said during the meeting that SMART arborists would "quickly" take 1,000 cuttings from the tree to attempt to reproduce it. But Stapleton said the pair later discussed that springtime may not be an ideal time to take the cuttings because of the delicate new growth.

Rohnert Park City Councilman Jake Mackenzie cut short the broadening discussion, suggesting the board discuss the issue when it is on the formal agenda. No timeframe for that has been determined.