Photo taken on Sept. 23, 2021 shows ripe highland barley against the backdrop of snow-covered mountains at Ombu Township, Nyima County, Nagqu City of southwest China's Xizang Autonomous Region. (Xinhua/Jigme Dorje)

Sitting around a dining table, several people of different ages were talking about 12 willows thousands of kilometers away in southwest China's Xizang Autonomous Region.

"It took years for their trunks to grow this thick," said Wang Yue, 66, scooping his hands into a size of a ping-pong ball.

"When I was there, they grew as thick as the width of a bowl mouth," said Gao Shengmin, 58.

"The trees are still alive with the branches trimmed, as they have almost reached the rooftop," said Gao Shuai, 44.

Every one of the diners from the China National Offshore Oil Corporation (CNOOC) is or was a cadre sent to Nyima County, a pastoral area with an average altitude of more than 4,800 meters, as part of China's national paired-up assistance to the development of Xizang.

Thirty years ago, the central government made a major decision to rally national support for Xizang. Under the paired-up assistance policy, some central state organs, provincial-level regions and centrally-administered state-owned enterprises were designated to assist in specific areas in the region. Since then, cadres from government and enterprise units have taken turns stationed on the plateau, greatly contributing to the development there.

With thin air, strong winds and harsh climate conditions, Nyima has no naturally grown trees in the county seat.

"Those trees managed to survive because they were planted in an indoor courtyard of our office building, like a greenhouse," Wang explained.

As one of the first cadres sent by the CNOOC from the coastal city of Tianjin to Nyima, Wang arrived at the county in 2002, when the infrastructure was still poor. As executive deputy head of the county, he contributed to constructing major roads, the government office building and a hotel. The willows were planted following the completion of the government building project.

In the hotel, there was an elevator, the first one in northern Xizang.

"When we contacted elevator companies, many turned us down because they were not sure whether their products could work at such a high altitude," Wang recalled, adding that a foreign company eventually accepted the challenge and installed the elevator, boasting "the world's highest in altitude" back then.

In 2004, Lyu Ming, also from Tianjin, took over Wang's work in the county. He recalled that driving from the regional capital, Lhasa, took two days to Nyima because there were no paved roads.

"Once, we lost our way and drove into a watercourse," he recalled. "Fortunately, a passing vehicle helped drag us out of the mud."

During Lyu's term from 2004 to 2007, Nyima got access to the national power grid and the telecommunication networks, ending the days when he could not call his family in Tianjin.

By 2010, when Gao Shengmin took over the baton, the infrastructure in Nyima County had significantly improved, with assistance efforts shifting from infrastructure construction to nurturing talent and stimulating industrial growth.

"The newborn mortality rate reduced from 20 percent to zero the first year after we organized training outside the region for local medical staff," he said with pride.

Fu Xiaoyu, who arrived in the county in August 2019, witnessed Nyima eradicated from absolute poverty later in the same year -- a historic achievement for the county.

He and his colleagues strengthened efforts to develop the animal husbandry and tourism sectors, including the construction of a hotel at a lake resort. They also helped Tibetan college graduates get employed outside the region.

Champa, born in 1995 in Nyima County, is one of them. He became an offshore oilfield operator in the Bohai Sea in 2020, two years after graduating from university.

"Inspired by my experience, several of my folks have found rewarding jobs outside the plateau," Champa said with a smile.

Over the last 22 years, the CNOOC dispatched 16 cadres to work in Nyima County, and 570 million yuan (about 80 million U.S. dollars) was poured into helping with its development. From 2002 to 2023, the county's GDP surged tenfold, with the poverty rate plummeting from 25.26 percent to zero.

Data showed that between 1994 and 2020, 52.7 billion yuan was injected into Xizang through the policy of paired-up assistance, with 6,330 projects.

Carrying on the projects left by Fu, Gao Shuai and his colleague Sun Peng are continuing efforts in rural revitalization and operating the lakeside hotel in Nyima.

"We must spend every penny properly to bring substantial benefits to the county and the lives of local people," Sun said.