China's forest coverage and stock volume still lag far behind global averages despite the country's efforts in forest planting, forestry experts said.

China is the fastest-growing country in terms of forest resources, Zhang Jianlong, head of the State Forestry Administration, recently told Shanghai-based thepaper.cn at a forum on forestry development.

Since 2005, the forest coverage of China has increased from 18.2 percent to 21.6 percent, and the urban green coverage of built-up areas has reached 36.4 percent, said him.

From 2005 to 2016, the carbon intensity - a measure of a country's emissions compared with each unit of its economic growth - has been reduced by 43 percent, according to report by thepaper.cn.

This is partly because of the increased carbon sinks from the growing forest coverage, which is estimated to absorb 500 million to 600 million tons of carbon dioxide annually.

Despite the country's efforts in forest planting, China faces challenges in further increasing the coverage rate and quality of planted forests.

China's forest coverage rate is still 10 percent lower than the world's average, and forest resources are unevenly distributed, said Zhao Shucong, deputy head of the National Afforestation Committee.

Forestation is becoming increasingly difficult as most of the remaining lands favorable for forests are located in arid or semiarid areas in north China or karst formations in the south.

The quality of forests also needs to be improved, he said.

The proportion of young and middle-aged forests is 65 percent, which is unreasonable for sustainable development, and the stock volume per hectare of forest is less than one-fourth of that in developed countries, according to Zhao.

Meanwhile, the annual value of ecosystem services per hectare of forest is only 40 percent of that in Germany and Japan, said Zhao.

A 2014 report of China Daily show that half of China's timber is imported, reflecting a serious deficiency.

By 2030, China aims to increase wood stock by 4.5 billion cubic meters - or around 30 percent - from the level of 2005.

To achieve that goal, the country has launched reforms on the paid use of natural resources as well as environmental damage compensation systems. And from 2018, the pilot mechanism of auditing natural resource assets of outgoing leading officials will be promoted nationwide.

"We should actively explore theories and methods in evaluating forest resources and include forests' values in the national planning and accounting system, thus fully realizing the value of resources and the environment," said Zhao.