Panda géant

The primary threat facing Giant Panda populations is the continuing effects of previous habitat loss, resulting in highly fragmented habitat and, in many cases small, isolated populations. According to the Fourth National Survey (State Forestry Administration 2015), the Panda population is composed of as many as 33 subpopulations, 18 of which contain fewer than 10 individuals. The extent to which these are demographically separate populations remains uncertain, but this fragmentation certainly increases vulnerability to extinction through environmental and demographic stochasticity and loss of genetic diversity.

Although microsatellite analysis (Lü et al. 2001, Zhang, B. et al. 2007, Shan et al. 2014) and genomics (Li et al. 2010, Zhao et al. 2013) have now determined that the Giant Panda has substantial genetic variability, without increased migration and connectivity, many of these smaller populations will have rapidly eroding evolutionary potential. Three genetic clusters have been recognized: the Qinling Mountains population (Lü et al. 2001, Zhang, B. et al. 2007) which diverged ~0.3 million years ago; the Mishan mountains, which diverged ~2,800 years ago into the Mishan and Qionglai populations (Zhang, B. et al. 2007, Zhao et al. 2013); and the other four combined populations, including Qionglai, Daxiangling, Xiaoziangling, and Liangshan (Zhan et al. 2013). However, in this larger cluster, further sub-structuring is manifest (Zhang, B. et al. 2007, Zhu et al. 2011b). Population divergence is the product of several operating factors, including climate change, natural barriers, and anthropogenic habitat loss.

Threats associated with edge effects, human disturbance, and small population size are most severe in these small, isolated populations. Increased fragmentation from roads, hydroelectric dams, mining, and other infrastructure projects further threaten Panda populations (State Forestry Administration 2015), but these trends are partially counterbalanced through the successful implementation of ecocompensation programs that curtail some activities such as fuel wood collection (Viña et al. 2007) and efforts to increase habitat connectivity between some populations (Wang et al. 2014, Wei et al. 2015a). Tourism is increasing in some areas and if not managed properly, could negatively impact Panda populations (Liu et al. 2012). Pathogens and parasites may be an emerging problem compromising Giant Panda health and survival, particularly in areas where dogs, livestock, and other domesticated animals may introduce novel pathogens (Qin et al. 2010; Zhang, L. et al. 2011, 2015). Air- or water-borne environmental contaminants may also exert negative impacts on Panda populations, but little is known about their prevalence. Livestock grazing, inside and outside of protected areas, represents another, potentially growing threat (Hull et al. 2014, Wang et al. 2015). It should also be noted that protected status of nature reserves does not always confer protection, and some threats have continued even after Panda reserves were gazetted (Liu et al. 2001). These continuing human activities may have cumulative effects that further degrade Panda habitat.

Pandas' reliance on bamboo as a primary food source puts them at risk during this plant's characteristic mass synchronous flowering and die-off events, which occur at intervals of 15 to 100 years (Schaller et al. 1985, Reid et al. 1989). Before human expansion confined Pandas to high elevations, Pandas had access to more species of bamboo adapted to different elevation zones. When one bamboo species experienced a die-off, Pandas could easily migrate up or down slope to access a different species that was not affected. Confined to its more limited elevation range today, Pandas are sometimes put at risk of starvation, especially when more than one bamboo species flowers at the same time. Although past bamboo die-off events were alarming and caused starvation and mortalities in Pandas, populations recovered (Pan et al. 2014) and these population bottlenecks did not compromise genetic diversity (Zhu et al. 2013).

These primary threats associated with habitat fragmentation and degradation may be exacerbated by climate change-mediated effects on Panda habitat in the future. Several models indicate significant losses to Giant Panda habitat, with estimates of loss of bamboo habitat ranging from 37% to 100% by the end of the century (Fan et al. 2012, Songer et al. 2012, Tuanmu et al. 2013, Li, R. et al. 2015). Although these models are simplifying and may not adequately account for distributional shifts of bamboo species adapted to lower elevations and southern latitudes to replace current habitat that might be lost (Wei et al. 2015a), managers should be concerned about large-scale environmental changes facing Panda populations in the future. In addition, climate change may alter the agricultural value of current Giant Panda habitat and bring about intensified human pressure for cultivation. For example, some models indicate that much of Panda habitat will become suitable for viticulture, a high-value crop (Hannah et al. 2013).

Although poaching impacted Pandas in the past (Li et al. 2003), its impact declined rapidly since the enactment of the Wildlife Protection Act, which bans poaching and carries severe punishments. However, Pandas may sometimes be caught in snares set for musk deer or other species.

The Giant Panda has been the focus of one of the most intensive, high profile efforts to recover an endangered species. In 1981, China joined the Convention on the International Trade in Endangered Species (CITES), which made trade of Panda skins illegal. Enactment of the 1988 Wildlife Protection Law banned poaching and conferred protected status to the Giant Panda (listed as Category I, the highest level of protection). The National Conservation Project for the Giant Panda and its Habitat of 1992 laid out a masterplan for Panda conservation and established a Panda reserve system, which today has grown to 67 reserves. Enlarged by more than 50% since the Third National Survey, this reserve system currently protects 67% of the Panda population and nearly 1.4 million hectares of Panda habitat (State Forestry Administration 2015). The biological diversity of these reserves is unparalleled in the temperate world and rivals that of tropical ecosystems (Mackinnon 2008), thus making the Panda an excellent example of an umbrella species conferring protection on many other sympatric species (Noss 1990).

These efforts to end poaching and protect Panda habitat played a significant role in Panda recovery. The Chinese government also invested in infrastructure and capacity building for reserve staff, established anti-poaching patrol, curtailed human activities inside reserves, and in some cases relocated human settlements from inside to outside of reserves. Other measures directed at broader conservation problems also benefited the Panda. The Natural Forest Conservation Program was implemented in 1997 to reduce the devastating impacts of flooding on human communities due to deforestation and erosion. The program banned logging in most forests in Panda habitat, slowing habitat degradation. Additionally, the Grain-to-Green Program incentivized farmers to plant trees on steep slopes to slow erosion. The result of these policies was the addition of 3 million hectares of forest cover in China annually, an increase of 1.6% per year from 2000 to 2010 (FAO 2010). As a consequence, Panda habitat is recovering and the total occupied habitat has increased by 11.8% between the Third and the Fourth National Surveys; an additional 6.3% increase in suitable but unoccupied habitat was also observed. In the Wolong Nature Reserve, implementation of the Grain-to-Green Program brought about measurable increases in connectivity of Panda habitat (Viña et al. 2007). Thus, these habitat conservation policies are associated with increasing Panda population size, increasing range, and better habitat connectivity. Efforts have also commenced to restore habitat corridors (Wang et al. 2014, Wei et al. 2015a) and to reintroduce captive-born pandas to increase genetic diversity in small, isolated populations.

Ecocompensation has been proposed as an important component of a conservation strategy for pandas (Yang et al. 2013, 2015; Liu et al. 2008, 2015; Tuanmu et al. 2015). Approximately 15% of the remaining unprotected habitat occurs in collectively-owned forests. Payment for ecosystem services, which has already been shown to benefit Panda conservation under the Grain-to-Green Program, could extend conservation measures into these unprotected areas.

Finally, the Giant Panda has been the beneficiary of a massive scientific effort conducted in partnerships between the Chinese government and institutions and international conservation NGOs and zoos (Swaisgood et al. 2010, Wei et al. 2015a, State Forestry Administration 2015). Once poorly understood, there has been an explosion of scientific studies across many disciplines, and this knowledge has increasingly been applied management and policy decisions. Future directions would benefit from even better coordination between science and policy, and the application of adaptive management principles in which experiments are conducted to evaluate management actions that may increase carrying capacity inside protected areas (Swaisgood et al. 2011, Wei et al. 2015a).

China's State Forestry Administration, while rightfully proud of its accomplishments, fully realizes that more work needs to be done to further Panda conservation and to avoid losing ground so painstakingly gained. They plant to continue investing in habitat protection, population monitoring, and protection patrols, and to further develop capacity of reserve staff (State Forestry Administration 2015). They recognize the challenges the future holds, and in particular will seek to address problems of habitat connectivity and population fragmentation.