The giant panda, the creature that has become a symbol of conservation, is f

游客2023-10-14  28

问题     The giant panda, the creature that has become a symbol of conservation, is facing extinction. The major reason is loss of habitat, which has continued despite the establishment, since 1963, of 14 panda reserves. Deforestation, mainly carried out by farmers clearing land to make way for fields as they move higher into the mountains, has drastically contracted the mammal’s range. The panda has disappeared from much of central and eastern China, and is now restricted to the eastern flank of the Himalayas in Sichuan and Gansu provinces, and the Qinling Mountains in Shanxi province. Fewer than 1,400 of the animals are believed to remain in the wild.
    Satellite imagery has shown the seriousness of the situation ; almost half of the panda’s habitat has been destroyed or degraded since 1975. Worse, the surviving panda population has also become fragmented; a combination of satellite imagery and ground surveys reveals panda "islands" in patches of forest separated by cleared land. The population of these islands, ranging from fewer than ten to more than 50 pandas, has become isolated because the animals are unwilling to cross open areas. Just putting a road through a panda habitat may be enough to split a population in two.

    The minuscule size of the panda populations worries conservationists. The smallest groups have too few animals to be viable, and will inevitably die out. The larger populations may be viable in the short term, but will be susceptible to genetic defects as a result of inbreeding.
    In these circumstances, a more traditional threat to pandas--the cycle of flowering and subsequent withering of the bamboo that is their staple food--can become literally species-threatening. The flowerings prompt pandas to move from one area to another, thus preventing inbreeding in what would otherwise be sedentary populations.  In panda islands, however, bamboo flowering could prove catastrophic because the pandas are unable to emigrate.
    The latest conservation management plan for the panda, prepared by China’s Ministry of Forestry and the World Wide Fund for Nature, aims primarily to maintain panda habitats and to ensure that populations are linked wherever possible. The plan will change some existing reserve boundaries, establish 14 new reserves and protect or replant corridors of forest between panda islands. Other measures include: better control of poaching, which remains a problem despite strict laws, as panda skins fetch high prices; reducing the degradation of habitats outside reserves; and reforestation.
    The plan is ambitious. Implementation will be expensive--56.6 million yuan(US 12.5 million) will be needed for the development of the panda reserves--and will require participation by individuals ranging from villagers to government officials.
    Summary
    The survival of the giant panda is being seriously threatened. Panda numbers have already seriously decreased. This is largely because the overall size of their【61】has been reduced, and habitable areas are now disconnected from each other. Two results are that pandas are more prone to【62】problems and are unable to move around freely to follow the growth cycles of the bamboo that they eat. A new plan aims to【63】existing panda habitats and to join many of them together. This plan also includes reforestation and the creation of【64】To succeed, everyone, including both the government and【65】, will have to cooperate. [br]

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答案 genetic

解析 由于熊猫的居住地分散,所以在一个居住地中可生育的熊猫数量少。第三段提到,因此,熊猫will be susceptible to genetic defects,容易遭受基因缺陷的问题。
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