Fortunately, the superiority of the old trees' genes gives the new trees derived from them an advantage over regular trees so long as pollution remains low, said Zhu.

Zhu said the cloning process causes little damage to the ancient trees from which tissue is harvested because researchers only need small pieces of them and modern gardening techniques can guarantee their safety.

Experts also suggest that considering the costs and safety factors, the number of the cloned offspring of every ancient tree be kept within 50.

Cloned Trees Show Their Strength

In China, there are many successful examples of cloned trees. Early in 2000, the State Forestry Administration of China built a breeding center in Zhanjiang, in south China's Guangdong Province, to clone eucalyptus trees by using advanced DNA technologies. In 2004, the Chengdu Institute of Forestry, the Chinese Academy of Sciences and the Chinese Academy of Forestry started researching tree-cloning technologies. They built a breeding factory in 2005. Researchers chose Australian eucalyptus trees as the objects of their research because they grow quickly and are also an important industrial raw material.

During the cloning process, scientists take buds from eucalyptuses and extract their genes to cultivate new buds in laboratories. Then, researchers in the sterile laboratory use tweezers to implant those new buds into a culture medium. When the new buds grow to have roots, they will be removed into those glasses with culture medium. After about 20 days, the buds with roots will grow to about 15 cm and can be transplanted into soil. After a period in the greenhouse, the tree saplings can be transplanted to where they will take root and grow.

According to Li Wenjun, Director of the Bamboo and Wood Industry Research Center of the Chengdu Institute of Forestry, their center can clone more than 10 million cloned tree saplings every year.

The cloned eucalyptus trees have been planted in many places around Chengdu. A 33,000-hectare industrial forest will be formed by the end of 2010, which will provide 750,000 to 1 million cubic meters of lumber to Chengdu wood processors every year.