Tree doctors help preserve city’s natural legacy

Joint efforts to conserve the environment and cultivate the economy have been credited for the continued success of the southeastern Guangdong city’s pillar petrochemical and electronics industries. Chai Hua reports from Huizhou.

Arborist Wang Lijun injects fluid nutrition into an old tree. (PROVIDED TO CHINA DAILY)

Editor’s note:February marks the fifth anniversary of the publication of the “Outline Development Plan for the Guangdong-Hong Kong-Macao Greater Bay Area”. In the eighth in China Daily’s series on the most intriguing stories to come out of the Greater Bay Area cities within the past five years, we take an in-depth look at Huizhou’s efforts to explore its development in an environmentally friendly mode, and searching for a scientific method to protect the precious ancient trees.

Huizhou, known for its beautiful, tranquil environment and picturesque landscapes, has the highest number of ancient trees in Guangdong province, with more than 13,100 ancient trees and some 14,000 protected key trees.

To protect this precious natural heritage, a dedicated team of arborists, or tree doctors, is deployed to examine, treat and take care of the majestic ancient trees.

Wang Lijun, who heads one of the teams, has examined and treated over 420 aging trees in Huizhou so far.

“A tree doctor is just like one who treats human beings. We have to carry out diagnosis, observation, investigation and palpation on aging or diseased trees,” he says. Before “curing” a tree, he has to examine the injured site and check it using professional equipment. “Surgery” will be carried out based on a treatment plan approved by the local forestry authorities.

Wang says the banyan tree — a native species in Huizhou — has shallow roots, and is prone to hollow decay and vulnerable to extreme conditions, such as storms and typhoons. But wrong practices and a lack of professional knowledge from their caregivers are mainly responsible for the deaths of ancient trees. “Some people ‘care too much’ for the trees in their village by applying cement around the roots to protect them. But this would suffocate the roots, creating a large number of floating roots that can weaken the plant’s ability to absorb water and nutrition from the earth.”

The tree doctors were recently assigned to treat a 155-year-old banyan tree whose branches were tilting to the left, lying almost parallel to the ground. The bottom of the trunk was almost completely hollow, with some bare black and brown bark like a scar.

After a thorough examination, Wang found that the tree’s branches had almost dried up, and the lower part of its bark was necrotic and rotting. “If we hadn’t removed the rotting part, it would have worsened, and the tree could have collapsed when the trunk could no longer support it. As the tree is located on the town’s main road, accidents could have occurred.”

The team treated the decay by planting permeability cells and applying fertilizers. They also erected support poles for the tree, giving it the appearance of an elderly man on crutches.

In another village, a 105-year-old tree was toppled by a typhoon last year, and only 10 percent of its roots could be preserved. Arborists had to cut off the leaves to reduce evaporation and enable the tree to recover before installing permeability cells in its roots.

Besides using root nutrient fertilizers, the tree doctors also “prescribed” fluid nutrition for use around the tree trunk to enable the tree to better transport nutrients from the root to the trunk.

Within half a month, the treatment had begun to pay off. The leaves had stopped deteriorating and a new bud had emerged on the trunk.

Huizhou has stepped up efforts in the conservation and management of ancient trees and renowned wood species, striving to protect every “living fossil” and provide a sustainable habitat for these remarkable treasures.

Moreover, the protection of ancient trees and renowned wood species has been integrated into the rural revitalization strategy, vigorously promoting the development of picturesque villages with abundant greenery.

CHINA DAILY丨HONG KONG