Reassessing the conservation status of the giant panda using remote sensing
DOWNLOADSeptember 26, 2017 - Weihua Xu, Andrés Viña, Lingqiao Kong, Stuart L. Pimm, Jingjing Zhang, Wu Yang, Yi Xiao, Lu Zhang, Xiaodong Chen, Jianguo Liu and Zhiyun Ouyang
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EmailJournal or Book Title: Nature Ecology and Evolution
Keywords: biodiversity; conservation biology
Volume/Issue: Online
Year Published: 2017
The conservation status of the iconic giant panda is a barometer of global conservation efforts. The IUCN Red List has downgraded the panda’s extinction risk from “endangered” to “vulnerable”. Newly obtained, detailed GIS and remotely sensed data applied consistently over the last four decades show that panda habitat covered less area and was more fragmented in 2013 than in 1988 when the species was listed as endangered.
The International Union for Conservation of Nature (IUCN) recently changed the status of the giant panda (Ailuropoda melanoleuca) from “endangered” to the less threatened “vulnerable”1. The justification was the observed increase in the adult population from the second national survey (1985–1988) to the fourth survey (2011–2014). Data collection methods, analyses, and sampling area were inconsistent, however, and this makes comparisons difficult. For instance, surveyed areas changed from 49 counties for the second survey2, to 57 counties for the third survey3, and to 62 counties for the fourth4. The increase to the fourth survey likely reflects there being more habitat and that the pandas are expanding their range.
To provide comparable estimates across surveys, we use consistent methods across the same geographical area in all years and include various measures of habitat extent and quality such as habitat patch size and fragmentation by roads. We also analyse the factors driving panda habitat changes. These are important for a complete conservation status assessment, but missing in IUCN’s assessment, which is based almost solely on population numbers while ignoring emerging threats. Our results show a more complicated picture that warns against complacency while providing benchmarks against which to compare future surveys and assessments.
Using an integrated model that combines elevation, slope and forest cover derived from remotely sensed data5, we evaluated the giant panda habitat across its entire geographic range from 1976 to 2013. Habitat decreased by 4.9% from 1976 to 2001, but increased by 0.4% from 2001 to 2013, despite the devastating 2008 Wenchuan earthquake. Mean patch size of the remaining habitats decreased by 24.0% from 1976 to 2001, but increased by 1.8% between 2001 and 2013. Habitat recovery has not offset previous habitat loss. For example, compared to 1988 when the panda was listed as endangered, the habitat area and mean habitat patch size in 2013 were 1.7% and 13.3% less than those in 1988, respectively.
