Along the Yarlung Zangbo River, winding through the river valley, ancient walnut trees with countless growth rings can be seen everywhere. Their sturdy branches stretch into the sky, and their towering canopies blot out the sun.

"It is hard to imagine that such a large community of ancient walnut trees is hidden at such a high altitude; it is even harder to describe what a person engaged in horticulture and landscaping feels when encountering them!" Liu Liping still remembers the shock she felt when she first arrived in Gyaca and saw the walnut trees.

Liu Liping is an associate professor at Yangtze University and a horticulture expert. In March 2021, she came to Gyaca County, Shannan City, with a team from Yangtze University undertaking Hubei Province's 14th Five-Year Plan science and technology aid-Xizang project.

She has stayed for five years, and this year renewed for another three.

At first, what was on her mind were the project, papers and professional titles. But over the next five years or more, Liu Liping increasingly felt that encountering the ancient walnut trees in her forties was a rare opportunity in life.

In the eyes of local residents, these ancient walnut trees were nothing unusual. For a long time, walnuts, apples, peaches and pears grew freely in front of and behind houses and in fields, without human intervention, relying only on nature. Due to a lack of effective management and care, the old trees suffered from varying degrees of trunk damage, root consolidation and natural aging.

Liu Liping began by gaining a clear understanding of the situation. On the plateau at an altitude of over 3,000 meters, she joined local officials and villagers in wading through streams, crossing hills, crawling through fences and climbing over mud walls to find the ancient trees scattered in deep mountains, river valleys and around villages. She registered, photographed, geolocated and attached exclusive QR code electronic archives to each one. A single round of visits took more than three months. After three rounds of surveys, Liu Liping had engraved all 3,657 ancient walnut trees in her mind. Today, without navigation or a guide, she can accurately locate these trees and tell whether their nuts taste good and what their oil yield is like.

Utilization is the best way for protection. These ancient trees must be made "useful." Liu Liping then began grafting walnuts. She blended textbook theory with Gyaca's climate bit by bit. After hundreds of controlled experiments on the plateau, she finally figured out the golden timing for plateau walnut grafting, and the grafting survival rate increased from less than 30%to nearly 90%. She selected six fine varieties suitable for the plateau from thousands of ancient trees and led the construction of a standardized scion collection nursery and seedling cultivation base of more than 50 mu, filling the gap in high-quality plateau walnut breeding in Shannan City.

On the barren slopes of Nuqiao Village, small walnut trees are growing vigorously. The successfully grafted branches are thick and strong, and some have already borne fruit. This is a 1,000-mu fine variety cultivation demonstration base invested in by the government. Under Liu Liping's guidance, technicians Ngodrupand Tsering at the base have become "local experts" in everything from planting and management to grafting and pest control. "In another five years, this place will surely be lush and green. We will see ecological benefits first, then gradually gain economic benefits. It takes ten years to grow trees; there is no rush," Liu Liping said.

To make the Gyaca walnut industry bigger and stronger, in addition to growing and selling walnuts well, it is also necessary to rely on the ancient walnut community to promote the integration of culture and tourism. "These trees would be wonderful for tourism," Liu Liping's words awakened Pasang in Lagang Village. Today, tourists enjoy Lingka picnics under the "king of millennium walnut trees in Asia," and Pasang can earn 100,000 yuan(RMB)a year. Liu Liping has become a free promoter of this small scenic spot. When she was free, she introduces the ancient walnut trees to tourists who come from afar. Her professional knowledge often makes visitors feel the trip was worthwhile. A few days ago, she even persuaded several tourists to stay overnight here.

"Gyaca's ancient walnut trees will definitely become hugely popular. I have that confidence!" Liu Liping said. In recent years, Xizang's cultural tourism has improved in both quantity and quality, and is transforming and upgrading from traditional sightseeing tourism to in-depth cultural experience tourism. Gyaca County is also strengthening industrial planning and promoting all-for-one tourism.

All parties are also joining forces. At the end of October last year, during an e-commerce livestream, nearly 20,000 jin of Gyaca ancient-tree walnuts were sold in 11 days. This year, the village-based task force of the Shannan Municipal Agriculture and Rural Affairs Bureau also helped connect with the commerce department. When the ancient-tree walnuts ripen in October, Gyaca's ancient-tree walnuts will be exported to Nepal.

When she first arrived, Liu Liping always carried milk candy and small snacks in her backpack, in addition to measuring tools and specimen bags. "Sometimes, a piece of candy win over a little guideand help find an ancient walnut tree hidden in front of or behind a house." Later, in order to find superior scion branches with good taste and thin shells for grafting, she was turned away many times in the first year or two, and could only grit her teeth and work on each household one by one.

Now, Liu Liping moves through villages and households with ease. Villagers vie to invite her home for tea, show her their fruit trees, and stuff whatever their family produces into her hands. Her field classes are also filled with fruit growers who come to learn management and care techniques. Some call her "Dr. Liu," others "Teacher Liu." Liu Liping knows clearly that in the past, everyone called her "Dr. Liu" as just a form of address; today, that "Dr. Liu" carries much more meaning.

Over the past five years, she has figured one thing out: What is aid-Xizang really for? And what should be left behind? In 2025, when the 14th Five-Year Plan project was completed, at the retention of county leaders, she signed another three-year contract with the county through flexible talent introduction. "I want to bet another three years."

What she wants to leave behind is ancient walnut trees that remain forever lush and flourishing, so that future generations can still rest in their shade.

Translator: Zheng Yujie

First Review: Zhi Xinghua, Zhang Yiming

Second Review: Drakpa Wangchen

Third Review: Hu Rongguo