How big should a forest be to make sure a sustainably sized group of pandas can survive, thrive, and live in comfort? The answer is 114.7 square kilometers, according to a study released Thursday in Scientific Reports, a journal published by Springer Nature.
Ten researchers from different institutes in southwestern China’s Sichuan province conducted the study beginning in early 2015. They analyzed traces of giant pandas’ presence, such as feces and footprints, in the natural mountain ranges of Sichuan and neighboring Gansu province that harbor more than 80 percent of all giant pandas remaining in the wild.
Past studies concluded that a sustainable group of giant pandas should have more than 40 individuals, Yang Zhisong, associate professor at China West Normal University and one of the authors of the study, told Sixth Tone. He added that the pandas’ long-term survival also depends on whether they have a large enough forest to call home. “Many of their habitats are segmented by highways, railways, dams, villages, and many other human activities,” Yang said.
In total, the researchers looked at five mountain ranges, starting from the northernmost — the Mingshan range, which straddles the border between Sichuan and Gansu — and continuing in a semicircle southwest of Chengdu, the provincial capital, to the Liangshan range. In their article the researchers write that the three southernmost mountain ranges are relatively more fragmented, while the two northernmost mountain ranges contain habitats that are larger and more continuous.
According to the country’s fourth giant panda survey, there were 1,864 giant pandas remaining in the wild at the end of 2013. But a third of the animals live outside of protected nature reserves and are consequently threatened by habitat fragmentation. “To protect the wild giant pandas,” Yang said, “it’s very important that we build corridors among those fragmented habitats and expand their forests.”
China’s central government announced on Monday its intention to build a giant panda national park encompassing all of the species’ current habitats. As part of the plan, some residents will need to relocate, and some mining operations and small dams will have to close. Similar initiatives were announced on the same day to protect the habitats of two of China’s most endangered large mammals: the leopard and the Siberian tiger. A national park for the Asian elephant is still under consideration.
Shanshui Conservation Centre, a Beijing-based environmental protection nongovernmental organization, has worked to mitigate human disturbance in some of the giant pandas’ forest habitats in Sichuan. Wen Cheng, project director at the organization, told Sixth Tone that many villagers in these areas rely heavily on the forests for their livelihoods.
Shanshui has tried to develop alternative, more sustainable ways of life for these people so that the region’s giant pandas can remain undisturbed, Wen said. “In some areas, where villagers don’t depend on forest products [for their livelihoods] like they used to, we’ve seen giant pandas and other wild animals come back,” he said.
This article has been updated to correct Wen Cheng’s title and to clarify his remarks.
(Header image: A panda rests at the Toronto Zoo, Ontario, Canada, Oct. 8, 2016. Steve Russell/Toronto Star via Getty Images/VCG)