Transplanting of Oaks Questioned as Practice Grows : Nature: Some experts say that most trees die after moving and that the risks aren’t worth the cost. Debate surrounds future of an unusual specimen in Calabasas.

Rosi Dagit has a thing for oak trees.

“I’ve been living, breathing and eating oak trees for years,” says Dagit, a field biologist and certified arborist.

But when it comes to the debate over a picturesque old oak in Calabasas, a harsh solution slips easily from the tree-lover’s lips: “Cut it down.”

The oak is considered a treasure because it was formed by oaks of two different species--a Valley oak and a coast live oak--that twined together into one tree. It stands six feet thick and more than 10 times as high.

To make way for a highway expansion project and still save the unusual tree, state Department of Transportation officials have agreed to move the oak 30 feet across Calabasas Creek at an estimated cost of $100,000. It’s the largest of six trees on the grounds of the Leonis Adobe Historical Museum in Calabasas that must be moved to make way for the Ventura Freeway project.

“We asked them to save the trees,” museum director Phyllis Jones said. “We have been assured by a number of tree people that those trees will live . . . so at least by moving them they have some chance of survival.”

But whether the Calabasas oak survives involves an issue that’s far from cut and dried among oak activists.

Many have started to ask whether the large sums of money spent on transplanting the trees is wasted, saying that most transplanted trees die and that the money could be better used preserving existing oak forests or planting new trees.

At the other end of the spectrum are those--often tree movers who profit from a growing business--who assert that oaks withstand transplanting well, saving valuable trees.

Although Los Angeles County and many municipalities have oak tree preservation ordinances, transplanting is rarely required. The issue arises from the oaks’ financial worth to developers, based on their good looks, dwindling numbers and the instant gratification that transplanting achieves--compared to the decades needed to grow replacements to an attractive size.

But others contend that developers favor transplanting because offers to move threatened trees may persuade the public, environmentalists and planning officials not to block construction projects on oak-growing land.

“The tree-moving companies will say you can move oak trees--no problem,” said Dagit, who is also a resource conservation consultant for the Topanga-Las Virgenes Resource Conservation District. “But biologists and arborists and many people who are involved with oak trees will all tell you this is a really risky and wasteful effort.”

To move an oak, workers build large boxes around the tree’s roots. The boxed tree typically remains in the ground for 120 days while its roots recover from the cutting needed and large cranes are then used to lift it out of the ground.

Dagit contends that the process is traumatic for the trees and that it’s difficult for them to re-establish themselves. “It’s like taking somebody’s 90-year-old grandfather and chopping off his legs . . . and saying he’s going to be OK,” Dagit said.

Stuart Sperber, president of Valley Crest Tree Co. of Calabasas, which was awarded the $250,000 contract to transplant the Leonis Adobe oaks, disagrees.

“Oak trees can be moved successfully,” Sperber said. “There are a lot of people who say ‘Don’t move them,’ but . . . if a tree has to be moved in order to build something and there are the resources to save it, then it should be saved.”

Sperber estimated that his company has moved more than 5,000 oaks in the past 44 years and cited a survival rate as high as 95%. Fees for moving an oak range from $1,000 to $100,000 depending on the size of the tree, which reflects a 50% to 75% savings over trying to purchase a similar nursery-raised tree, he said.

Experts agree that oaks can be moved, but they caution that it is a complicated process.

“Large trees can be moved and they have been moved quite successfully,” said Richard Harris, professor emeritus of landscape horticulture at UC Davis.

Gene Himelick, a retired professor from the University of Illinois in Urbana and author of the “Tree and Shrub Transplanting” manual, cautioned that the larger the tree, the tougher the move. Whether a large tree will survive a move depends, he said, on the tree’s species and size, the soil it is planted in, how far and when it is moved, and the equipment and experience of the movers.

Trees broader than a foot thick have a particularly hard time surviving, he noted.

Others say it’s difficult to gauge how many trees survive for long periods because few studies have been done on the topic.

“It is questionable and at the very best, until we have 10 years of experience under our belts, we won’t know,” said Sharon Johnson, a founding and present board member of the California Oak Foundation, and co-author of the book “Oaks of California.”

Herbert Spitzer, assistant chief of the forestry division of the Los Angeles County Fire Department, which performs oak tree reviews on proposed development sites for the county’s oak tree ordinance, said some recent projects have had initial success, but that “they still haven’t stood the test of time.”

“We won’t make it a standard recommendation to move an oak until there’s some empirical data to support it,” said Spitzer, who makes recommendations to the county’s Regional Planning Department. “And then you have to ask another question--how long the tree has to survive for it to be a proved practice?”

But armed with limited amounts of existing research, Dagit and others contend that too few trees survive a move to make transplanting worthwhile. “The thing to do is to be honest and cut it down, instead of spending the thousands of dollars keeping it alive in a horrific state,” Dagit said.

“If you take the $100,000 and use it to plant trees, five years from now, the place will have a forest. But if they move the tree, in two years, it could be dead and what will the public have then but a dead tree?” she said.

A study of 593 oak trees moved at a development project in Orange County determined that 57% of the trees had died three years later, with another 14% in declining condition, said Tom Scott, a UC Riverside researcher.

“At least 71% of those trees are going to die, if not more,” Scott contended.

Dagit is also monitoring 10 oaks at a development site in Calabasas that have trunks ranging in size from two to 16 inches. Dagit determined five months after the April move that two trees had died, two showed signs of severe stress and two others were moderately stressed.

“If Tom Scott’s information holds true, that once a tree begins to decline it continues to decline, it will mean the 80% initial survival will be followed by an additional decline over time of at least another 20% to 40%,” Dagit said. “That would provide an overall survival rate of somewhat less than 50%.”

But proponents of the practice cite much different figures.

Sperber pointed to the 1,500 trees his company moved for billionaire David H. Murdock around his posh 630-dwelling development and country club at Lake Sherwood in the hills south of Thousand Oaks. Trees were uprooted from housing areas and replanted along the golf course at a cost of $6 million.

“We have a 99% survival rate,” Sherwood Vice President Elaine Freeman said of the 1,400 trees that have been moved since the project began in 1987. “We’ve done really well out here, but a lot of time and money has been spent to make that happen.”

Dagit, who said she has viewed the trees three times from a car, most recently in November, disagreed. “I saw some trees that were OK, some trees that were clearly stressed and some trees that were dead and/or dying.”

Murdoch has spent millions moving the trees and another $750,000 has been budgeted to complete the project, which includes transplanting 100 more, Freeman said.

Those figures don’t include maintenance, which could cost of thousands more depending on how soon and how successfully the trees adapt to their new home.

But maintenance plays a key role, both sides agree. “It’s like taking somebody out of a surgery and putting them in an intensive care unit,” Dagit said. “They need a lot of attention.”

“The track record has been very poor in terms of success rates of transplanted oaks,” said Mike Wilkinson, a deputy forester in the county Fire Department. “There have been projects that have had a 90% success rate, but they’re willing to spend large quantities of money.”

The boom in tree transplanting coincides with an increase in housing construction in “oak woodlands and mountain areas where there are trees,” Sperber said, adding that only in the last 10 years have developers been choosing to transplant trees on a large scale because oak trees boost land values.

Alden Kelley, a Fullerton-based arborist who works for developers, said: “It’s probably more political than environmental at this stage,” aimed at generating positive publicity and pacifying environmentalists and planning officials who might otherwise block building proposals.

Although many Southern California cities and counties have passed oak tree ordinances in recent years, few require that oaks be moved as mitigation. Most ordinances require builders to secure permits to remove oaks or to plant replacements. A Los Angeles County ordinance mandates a 2-for-1 replacement ratio and requires developers to replace newly planted trees that die within two years.

Rosemead, Monrovia, San Marino, San Gabriel, South Pasadena, La Verne and have adopted their own ordinances, as have cities in Ventura County.

Only time will tell whether the oak in Calabasas will survive the move.

Dagit contends that the tree’s size and the fact that it was formed by two separate trees will lower its chances.

“Caltrans is taking advantage of it because it looks good to save the tree by moving it 30 feet, but that’s a joke,” Dagit said. “The only way to save that oak is to build the freeway around the tree.”

Caltrans Engineer Jim McAllister counters that landscape designers at his agency estimate that the tree has an 80% chance of survival, “so it’s money well spent.”

Such optimism isn’t shared by oak enthusiast John Westervelt, a retired teacher who said he’s been enjoying the oak’s beauty for years.

“I’ve known that tree for years and years now,” Westervelt said. “It evokes a story of the past for me. It’s a very cultural, botanical and romantic feeling. . . . I don’t want them to touch it.”

California’s Oak Trees

Genus: Quercus

Variety: More than 400 species of oaks exist, nearly 80 of them native to the United States and about 16 tree species native to California, without counting oak shrubs.

Maintenance: Oaks that grow in California have adapted to the region’s drought-prone conditions so they need not be watered in summer. Only during a prolonged drought should the oaks be judiciously watered in the area unshaded by the tree’s canopy November through April. Pruning is best left to experts.

Landscaping: Planting water-thirsty greenery around an oak is not recommended. A few exceptions are drought-tolerant plants like milkmaid, California fuchsia and blue-eyed grass. Leaving a layer of oak leaves around the tree will also act as a mulch.

Life span: Oaks typically will live for more than 400 years, but some have been known to survive for more than 1,000 years.

Size: Some have grown to 11 feet in diameter and up to 90 feet tall.

Value: Some experts say an oak can add 25% to 30% to a home’s value.