Panda habitats are shrinking and becoming more splintered

Nearly three decades of conservation efforts to protect giant pandas has led to recent increases in their populations. A study by Chinese and U.S. scientists, however, has found that giant panda habitats cover less area and are more fragmented than when pandas were first listed as an endangered species.

“The International Union for Conservation of Nature (IUCN) has recently changed the status of the giant panda from ‘endangered’ to the less threatened ‘vulnerable,’ ” said researcher Stuart L. Pimm of Duke University. “This was based on the increasing numbers, which are a very encouraging sign, of course.”

“But what my colleagues and I wanted to know was how the panda’s habitat has changed over the last four decades, because the extent and connectivity of a species’ habitat is also a major factor in determining its risk of extinction,” said Pimm.

The researchers used geospatial technologies and remote sensing data to map changes such as new roads that divide panda habitats across the panda’s entire range. The scientists focused on geographical changes that occurred from 1976 to 2013.

The team was led by Zhuyan Ouyang and Weihua Xu of the Research Center for Eco-Environmental Sciences at the Chinese Academy of Sciences.

“We found complex changes,” Xu said. “Habitat decreased nearly 5 percent from 1976 to 2001, but has increased since. However, the average size of the habitat patches decreased by 23 percent from 1976 to 2001. It has increased only slightly since.”

Study co-author Jianguo Liu of Michigan State University pointed out that some of the changes revealed in the study are encouraging.

“Banning commercial logging in natural forests, establishing nature reserves and helping residents in the reserve change behaviors that damaged habitat has been beneficial,” said Liu. “But conservation is a dynamic process with humans and nature in a constant push and pull to survive and thrive, so new solutions always are in demand.”

Other changes observed by the researchers are advantageous to humans yet hinder progress in conservation efforts.

“The most obvious changes in this region since Professor Liu and his colleague Professor Zhiyun Ouyang first visited it together in 2001 have been the increase and improvement in roads and other infrastructure,” said Pimm. “These have been the major factor in fragmenting the habitat. There was nearly three times the density of roads in 2013 than in 1976.”

“We suggest several solutions,” said Ouyang. “One of the most important will be to establish protected corridors through which pandas can move to prevent their isolation into small and unsustainable populations.”

The study is published in the journal Nature Ecology and Evolution.

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By Chrissy Sexton, Earth.com Staff Writer

Image Credit: Binbin Li