More trees may actually be harming the environment in China

Forest management that encourages biodiversity needed.

Kumming (22 September 2011) - China’s focus on increasing forest cover could be better managed to protect ecological functions and provide livelihood benefits writes World Agroforestry Centre scientist Jianchu Xu in Nature Magazine.

China has planted more than 4 million hectares of new forest each year since the 1990s and President Hu Jintao has promised another 40 million hectares in the next decade.

While this sounds impressive, Jianchu warns a large part of the so-called forest cover is actually monoculture plantations of non-native trees such as fruit trees, rubber and eucalyptus. He believes this threatens ecosystem services, particularly watershed protection and biodiversity conservation.

“Exotic tree species are being planted in arid and semi-arid conditions, where perennial grasses with their extensive root systems would be better protectors of topsoil,” writes Jianchu. “Plantation monocultures harbour little diversity; they provide almost no habitat for the country’s many threatened forest species.”

Such plantations also generate less leaf litter and other organic inputs than native forests, so soil fauna and flora decrease, and groundwater depletion can be exacerbated by deep-rooted non-native trees that use more water than native species.

Much of the tree planting efforts in China in recent years have come out of the privatization of what were previously collective forests.

Jianchu is calling for a re-think of China’s one-size fits all forestry mandate to an approach that considers the country’s diversity of landscapes and ecosystems.

“I have seen massive tree plantations on the Tibetan Plateau, in areas where forests never grew before.”

“I would like to see China establish parallel forest-management programmes for recovery and restoration of natural forests, and for incorporating working trees into farmlands.”

“A dual strategy could ensure that China’s massive investment in forests provides maximum benefits, to both local livelihood and the environment.”

Jianchu Xu is a senior scientist at the World Agroforestry Centre and a professor at the Kunming Institute of Botany, Chinese Academy of Sciences.