LHASA, May 13 (Xinhua) -- Nagqu, China's highest city at an average elevation of over 4,500 meters, has achieved the seemingly unachievable: it is no longer "the city without trees."

Once a barren landscape where even survival was a challenge, this northern Xizang city has rewritten its ecological destiny through decades of perseverance, marking a historic breakthrough in high-altitude afforestation.

Perched on the Qinghai-Tibet Plateau, Nagqu was officially reclassified as a city in May 2018. Its thin air, with oxygen levels just half those at sea level, and relentless winds have made it a place where boiling water barely reaches 85 degrees Celsius and packaged goods swell as if ready to burst.

For many years, the absence of trees was a defining feature, so much so that award-winning female author Ma Lihua once wrote in her travel notes that "Nagqu Town has everything, except a tree."

Now, parks and sidewalks across Nagqu are dotted with alpine willow, spruce and sea buckthorn -- a testament to a quiet revolution. On the city streets, billboards reading "promote high-altitude greening, erase Nagqu's treeless legacy" proclaim this remarkable transformation.

"Nagqu has achieved China's highest-altitude success in tree planting," said Cewang Rigzin, director of the city's forestry and grassland bureau. Since 2021, the city has invested heavily in afforestation, forest management, and experimental planting in high-elevation urban areas.

"When I was a child, I could only see green trees on TV or in photos. Now, we've successfully trialed tree planting in urban areas, with a survival rate of over 80 percent," said Dainzin Puncog with the bureau, a native of Nagqu.

The trial planting of trees in Nagqu's high-altitude, frigid plateau began in the 1990s. Generations of local families and officials have poured efforts into this achievement, turning what once seemed a fanciful idea into reality.