Recently, good news came during a press conference about new technologies jointly hosted by the Beijing Municipal Administration Center of Parks (BMACP) and the Association of Parks and Greenbelts in the city.

"In order to guarantee the continued survival of those rare and valuable ancient trees, we have decided to adopt advanced cloning technologies," said Cong Richen, Director of the Tree Research Center under the Beijing Institute of Gardening Sciences.

Cong said researchers have selected different types of trees over 100 years old, which include ancient cypress trees, pines, gingkoes and scholar trees, to clone 100 of them within three years using the test tube tissue culture.

Currently, the city's government has marked the exact locations of all the old trees using GPS technology so that researchers can better understand their growing conditions and take care of them properly, Cong said. Now BMACP keeps records on 40,721 ancient or rare trees, among which 3,606 are more than 300 years old. The more than 10 parks under BMACP are home to 13,814 ancient trees, which account for 35 percent of the total in Beijing. More than 2,000 ancient trees in the parks are in the first-class (more than 300 years old), accounting for 59 percent of the city's total of first-class ancient trees.

There are also a couple of ancient trees in the Forbidden City's Imperial Garden, the pines in the Summer Palace and ancient gingko trees in the Beijing Botanical Garden.

The gene map of an ancient tree displays less genetic variety than ordinary trees and the genetic makeup of old trees has allowed them to live exceedingly long lives, according to an article in Beijing Science and Technology News. Once the trees die, however, those old-age genes will vanish along with them, and that is why advanced breeding technologies are needed to protect the uniqueness of those trees, said the article.

There are three breeding methods available to scientists--seed breeding, cuttage and test-tube tissue culture or cloning.

Experts in Beijing have gained experience in seed breeding technology and have completed successful experiments on some ancient trees in the city. "Our next step is to make clones of them," said Cong.

The tissue culturing of plants is one type of cloning technology, in which a piece of a stem's tip is removed and placed in a sterile nutrient medium where it can multiply. After it grows buds and roots, it is transplanted into flowerpots and then to a suitable location for it to grow and mature.

"In the past, a good and easy way to grow new plants was to collect seeds and grow the offspring of ancient trees. There was an unavoidable problem with that method, though. Variations naturally occur in the genes between generations, which would add uncertainty to the outcome," said Zhu Chunquan with the World Wide Fund for Nature's Beijing Office. However, cuttage and test-tube tissue culture can avoid the problem, Zhu said.

Cuttage, another common method to breed plants, refers to cutting stems, leaves, roots or buds to breed them in soil, sand or water and then move them to nursery gardens. There they grow roots and develop into new independent plants. In agriculture and forestry, different plants require different environments during the cuttage process. To guarantee survival, researchers must pay attention to choosing strong stems without pest or disease damage and taking care of them scrupulously, keeping the temperature in a certain range, maintaining humidity by using plastic films and ventilating the area.

"Cuttage has its limits. Some trees cannot be bred with cuttage. Those are the ones that we use cloning methods on," said Zhu, adding that test-tube tissue culturing can keep genes stable, making it an effective way to prevent the loss of those old trees.

At the same time, Zhu said that the trees' genes alone were not enough to guarantee the long life of those new trees gleaned from them. Other factors, such as growing places, conservation and others, are also needed.