About 1.3 million trees have been planted on the bare mountains in Lhasa, capital of southwest China's Tibet Autonomous Region, over the past seven years amid efforts to add greenery, local authorities said.

Over the period, the plateau city has afforested nearly 400 hectares of mountainous areas, with its forestry coverage reaching 19.49 percent last year, according to the city's forestry and grassland bureau.

The bureau also said Lhasa was the first city in Tibet that had successfully planted trees on mountainous areas with an altitude of more than 3,900 meters.

In a bid to improve the local natural environment, Tibet has launched a spate of ecological projects in recent years, including returning farmland to forest and curbing desertification.

Official data showed the region's forest coverage rose from less than 1 percent in 1951 to 12.14 percent last year.