Study disputes success of forest effort

Source: NYT (5/4/17)
Trees or Shrubs? Study Disputes Success of China’s $100 Billion Forest Effort
By MIKE IVES

HONG KONG — China has invested more than $100 billion over the last decade alone in a nationwide campaign to plant new forests, and its top leaders speak of the effort with pride.

“Planting trees now will benefit our future generations, and we should roll up our sleeves to plant more trees year after year, generation after generation,” President Xi Jinping said in March at a tree-planting ceremony in Beijing.

But a study published on Wednesday suggests that some official estimates of China’s greening campaign overstated its successes, and mistook shrubs for forests.

United Nations data, which are based on national statistics, show that between 2000 and 2010 China gained 167,568 square miles of forest, an area slightly larger than California. China’s own estimates were not far behind.

But the newly released study, based partly on an analysis of high-resolution photographs, found that China had gained only about 12,741 square miles of forest over the same period, an area roughly the size of Maryland. And it found that much of the government’s reported new forests were actually just collections of shrubs.

“China’s forests are not as green as we think,” Xu Jianchu, a co-author of the study and a professor of ethnoecology at the Kunming Institute of Botany in southwest China, said in a telephone interview.

Lu Zhi, a conservation biologist at Peking University in Beijing, who was not involved in the study, said its findings were consistent with recent research suggesting that China’s forest resources have not significantly increased despite the government’s extensive tree-planting campaign or its efforts to halt commercial logging in forests.

The authors of the study, published in the journal Proceedings of the Royal Society B, wrote that their results highlighted a need for more refined forest monitoring and a better way of measuring performance of Chinese forests based on “climatic suitability.”

“These findings indeed point to major gaps between the way the concept of forest is defined in the various international conventions, versus how the general public understands it,” said Meine van Noordwijk, a professor of agroforestry at Wageningen University in the Netherlands and the chief science adviser for the World Agroforestry Center. He was not involved in the study.

The study’s authors wrote that the United Nations forestry data was far higher than their own estimates in part because it counted young plantations and bare land that is earmarked for planting new forests. Places where modest forestry gains were detected in China were often not targeted for afforestation, they wrote, because the land was in demand for agriculture or urbanization.

Pinpointing tree-cover change in China is globally important, the authors wrote, in part because China is the world’s leading timber importer and has invested more money than all other countries combined in tree-planting.

The major reason for ambiguity in forest estimates worldwide is that there are over 800 official definitions for the term “forest,” with criteria ranging from over 10 percent to over 30 percent tree cover, the journal Nature Climate Change reported in 2015.

Mr. Xu said the newly released study underscored that the Chinese government should pay closer attention to the areas it targets for new forests, and avoid its practice of planting trees in semi-arid regions and deserts. “It’s time to look at both the economic efficiency and the ecological returns,” he said.

Mr. van Noordwijk said that to avoid such discrepancies in measuring forests, researchers could either clearly differentiate subcategories under the “umbrella” term of forest, or else avoid the term entirely.

“Once you are over the initial shock, the latter is actually feasible,” he said.

Leave a Reply

Your email address will not be published. Required fields are marked *