Conserving Old Trees

Ancient tree protection receives more attention By Ji Jing

In the yard of the Xifeng Temple in west Beijing, there is a 35-meter-tall gingko tree with a maximum diameter of 8.5 meters.The tree, which is more than 1,000 years old, has received a round of protection in the past few months.

The tree has many branches and its branches have been broken three times due to natural disasters. The tree also has large hollows that have required attention.

In 2021, the Beijing Afforestation Foundation invited experts on ancient tree protection to examine the tree and formulate protection plans.

Ancient tree expert Gu Runze toldBeijing Dailythat it’s not easy to strengthen the tree and the project requires a large amount of work. The team has used 56 6-meter-long steel structures to support the tree, each with a finish imitating gingko bark to minimize their visual impact.

These protection measures appear to have boosted the vitality of the tree, which has already begun to sprout new branches.

There are many ancient trees in China like the one at the Xifeng Temple. According to the second Ancient and Famous Tree Census, released by the National Forestry and Grassland Administration in September, there are 5.08 million ancient trees in China, of which 246,600 are in cities and 4.83 million are in rural areas.Ancient trees are defined in China as those aged over 100 years old.

The census started in 2015 and covered 31 provinces, autonomous regions, and municipalities. The census did not include nature reserves,state-owned forests in northeast China, Inner Mongolia Autonomous Region, southeast China and northwest China, or Taiwan, Hong Kong and Macao.

There are more than 70 ancient tree species in China, with indigenous species such as giant cedar and Chinese scholar tree accounting for more than 90 percent of all ancient trees.

Ancient trees bear testimony to history. Of the more than 5 million trees found in the census,more than 200 were planted by well-known historical figures. For instance, a cypress at the Imperial Ancestral Temple, now also known as Beijing Working People’s Cultural Palace, next to the Palace Museum, was planted by Emperor Yongle of the Ming Dynasty (1368-1644). “These trees(planted by historical figures) are more than just trees. They have great historical and cultural value,”Cong Richen, a researcher with Beijing Institute of Landscape Architecture, toldScience and Technology Daily.

In addition to historical and cultural value,ancient trees also have scientific value. Luo Huixin, Vice Chairman of Beijing Afforestation Foundation, said ancient trees have many good genes, which has helped scientists to breed improved tree species. Scientists can also study the evolution of climate and the natural environment in ancient times based on the growth rings of ancient trees.

Ancient trees can also increase biodiversity.Owing to their sprawling roots and luxuriant foliage, ancient trees form a small biosystem by themselves. They serve to regulate the climate and provide habitat for animals. For instance, an ancient banyan tree in Tianma Village, Jiangmen,Guangdong Province, forms a forest by itself. Its offshoots cover more than 1.3 hectares, providing shelter for 105 bird species. More than 300 plants and over 200 wild vertebrates have been found around the tree.

Careful protection

Beijing has more than 40,000 ancient trees,making it the city with the most ancient trees in the world. According to the Office of Beijing Greening Commission, since last year, Beijing has built 20 pilot parks and communities for protecting ancient trees.

Wang Yongge, an expert with Beijing Institute of Landscape Architecture, said, “To find the causes of an ancient tree becoming weak, not only the part above ground should be examined but also the soil underneath the tree needs be tested.”

An ancient tree might become weak as it ages and its surrounding environment changes. For instance, building new roads or architecture near an ancient tree might destroy its living environment and hinder its growth.A lack of protection measures during extreme weather may also affect the growth of ancient trees.

The Beijing Institute of Landscape Architecture has developed a seriesof technologies for strengthening and protecting ancient trees. “We have developed a machine to trim ancient trees. We also have a machine for loosening the soil around these trees,” Wang said.To address serious hollows in ancient trees, researchers have invented a technique to repair the trunk that does not alter the appearance of the tree and does not affect its growth.

(Above) An ancient cypress in Luonan County, Shangluo City,Shaanxi Province,on March 13

A gingko tree that was planted more than 1,200 years ago in Shanghai,on December 11, 2019

At Shijingshan, a hill in Shijingshan District in west Beijing, there are nine old giant cedars,three of which are more than 300 years old, one locust tree and seven other old trees which are nearly 100 years old.

“We should not only protect the trees themselves but also create a good habitat for them,”Fang Fang, an official with the Office of Beijing Greening Commission, toldBeijing Daily.

To protect the old trees and their surroundings, a protection area of 2.42 hectares was set up at the hill. Chen Wei, an official with the Shijingshan District Gardening and Greening Bureau, said the vegetation around the giant cedars has been cleared because it competes with the trees for sunshine and water. Instead, flowering shrubs have been planted around the old trees.

The Chinese scholar trees are susceptible to internal rot, which leads to hollows and may cause the trees to suffer malnutrition or warp.Experts have cleared these cavities of rot, sterilized the cavities, killed the pests and filled the cavities.

Now that the protection measures are complete, the old tree protection area will open to the public to enable them to learn more about ancient trees and increase awareness of protection.

Luo said more public awareness is needed to prevent both illegal activities and fire hazards that may impact the health and protection of the trees.

Laws regarding ancient tree protection should be improved. Cong said now almost every province and city has their own regulations on ancient tree protection. However, to further enhance ancient tree protection and deter illegal activities, a national law should be formulated.

He added that protection should adopt scientific measures to prevent possible damage to ancient trees. BR