WASHINGTON: More than 60 percent of the wild giant panda population in China's Sichuan province was affected by the powerful quake that rocked the region and killed thousands in May 2008, a study said Monday.

Ecologists also found that the massive 8.0-magnitude earthquake, which triggered huge landslides across the region's mountainous terrain and left nearly 87,000 people dead or missing, destroyed nearly a quarter of panda habitat close to the tremor's epicenter.

"It is probable that habitat fragmentation has separated the giant panda population inhabiting this region, which could be as low as 35 individuals," said Weihua Xu of the Chinese Academy of Sciences in Beijing, the lead author of the study published in Frontiers in Ecology and the Environment.

"This kind of isolation increases their risk of extinction in the wild, due in part to a higher likelihood of inbreeding."

Sichuan is designated as one of 25 global biodiversity conservation hotspots. The province, which contains more than half of the Earth's wild giant panda population, is home to over 12,000 plan species and 1,122 vertebrate species, noted Xu.

The researchers' analyses -- which involved satellite images taken before and after the quake in the South Minshan region close to the earthquake's center -- revealed that over 354 kilometers (220 miles), or 23 percent, of the pandas' habitat had become bare land.

Much of the remaining habitat areas were also found to have been fragmented into smaller, disconnected patches, which Xu said was just as harmful as the habitat being destroyed.

To produce its estimates, the study had used criteria that make forests suitable for pandas, such as the presence of bamboo -- the pandas' main food source -- elevation and slope incline.

In order to encourage pandas to move between the disconnected patches, the study recommended that specially protected corridors be built and that some areas outside of nature reserves also be protected.

The earthquake caused twice more damage to panda habitat outside than inside the reserves. The researchers also proposed that panda habitat be taken into consideration during the relocation of affected towns after the quake.

"It is vital to the survival of this species that measures are taken to protect panda habitat outside nature reserves," Xu said.

"Giant pandas in this region are more vulnerable than ever to human disturbance, including post-earthquake reconstruction and tourism. When coupled with these increasing human activities, natural disasters create unprecedented challenges for biodiversity conservation."

Some 600 giant pandas are still living in the wild, according to estimates.

Protection plans for the endangered mammals recommend establishing several dozen reserves across Sichuan, Gansu and Shaanxi provinces in China.