问答题 The magnitude of the problem of disappearing species, viewed worldwide, dwarfs resources currently available to address it. By the end of the century, experts predict, one species will be lost every hour. Faced with shrinking budgets and accelerating extinction rates, environmental managers agonize over which species to save. (1) Different criteria for placing value on species--ecological, economic, aesthetic, cultural--compete with one another, and controversy abounds. One proposal for sidestepping direct debates about the value of species is to adopt a system of triage, which takes its name from the French policy of sorting wartime casualties into three categories for medical treatment: those with superficial wounds that do not require immediate attention; those with wounds too serious to make treatment efficacious; and those in the middle range, having serious but treatable wounds.
Once the issue is formulated in this manner, it seems obvious that efforts toward species preservation are best concentrated in the third category. (2) Scarce funds and energies should be targeted at saving those species that are both in need of saving and susceptible to being saved. But the most arresting formulation of an issue is not always the most illuminating one; (3) it will be useful to stand back from the triage formulation (三级分类法), which casts the problem of setting priorities as one of sorting species into categories, and ask whether there are other, more fruitful ways to look at the problem.
The endangered species problem is not a single problem. It is more accurately seen as four closely related problems: what should be done when a species' population becomes so depleted as to threaten its continued existence; (4) what should be done to keep relatively healthy populations from declining and thereby falling into the threatened category; how to avert, or at least slow, the predicted and potentially cataclysmic reduction of biological diversity over the next few decades; and how to slow the trend toward conversion of natural systems to intense human use?
In the triage formulation the priorities problem is most naturally associated with the first question, because it considers threats to individual species. (5) Once threatened, species require management initiatives designed to protect and nurture them, individually. But the goal of protecting biological diversity should not be reduced to the goal of protecting remnant populations of threatened species. If one thinks about the endangered species problem in this way, there is a tendency to treat it as merely a problem of protecting genetic diversity, with each species regarded as a repository for a set of genes.