Residents of the capital might soon enjoy life in the shade as the city heads toward completing a large-scale greenbelt program ahead of time, according to forestry authorities.

Though the planting season ended in May, with 136 square kilometers covered with green in an afforestation project the government launched in March, planting continues as the city takes advantage of the rainy weather lately.

"It's likely the capital will be covered with more green earlier this year," said Fang Hao, an official with the Beijing Landscape and Forestry Bureau.

The 166-sq-km afforestation project, is concentrated mainly around the Sixth Ring Road. Its purpose is to help clean pollution from the city air and provide a more pleasant living environment.

By May 8, more than 13 million trees were planted, covering 137 sq km of the city's plain region, amounting to 83 percent of the project, according to the statistics from the bureau.

The mild, moist weather as summer begins has allowed the government to continue planting.

According to Fang, the city is confident the work will be finished by the end of the year.

"Most of the greenbelts are meant to surround the ancient city at its Sixth Ring Road, mainly around the urban-rural fringe zone," he said.

The capital has increased green areas through previous planting programs, but their distribution is not well balanced, with large forests covering the mountainous areas while the densely populated downtown lacks sufficient trees.

Planting trees around the Sixth Ring Road will benefit city residents and not take up too much space downtown.

The trees surrounding the capital will block pollutants from neighboring provinces, reducing PM 2.5 (particulate matter smaller than 2.5 micrometers in diameter). This could help reduce the rates of cardiovascular and respiratory diseases and even lung cancer, which are caused in part by polluted air, said Tong Haiming, deputy director of the bureau's publicity department.

According to the Beijing Environmental and Protection Bureau, 24.5 percent of PM 2.5 pollutants in the capital come from neighboring provinces. Blocking them would greatly improve the city's air.

Tong said the improvement will be gradually felt after the project is completed.

"The community will have a more pleasant living space once the messy urban-rural fringe is replaced by greenbelts and shade corridors," he said.

The government will open more green space to the public, creating more parks and gardens and giving free admission to some existing ones, Tong said.

"We will make more forest parks in the city's new satellite towns to further expand the green space," he said.

The city now has 348 parks, compared with fewer than 200 in 2005. The area has increased from 63 sq km in 2005 to 100 sq km.

According to Tong, planting trees is not enough in the fight against pollution and to provide recreational resources for residents. What is of equal importance is good conservation and care for the trees.

"It's important that the government and the public take good care of the 'green lungs' of the city," he said.

Contact the writer at zhengxin@chinadaily.com.cn