One basic weakness in a conservation system based wholly on economic motives is that most members of the land community have no economic value. Yet these creatures are members of the biotic community and, if its stability depends on its integrity, they are entitled to continuance. When one of these noneconomic categories is threatened and, if we happen to love it, we invert excuses to give it economic importance. At the beginning of century songbirds were supposed to be disappearing. (46)【Scientists jumped to the rescue with some distinctly shaky evidence to the effect that insects would eat us up if birds failed to control them. The evidence had to be economic in order to be valid.】 It is painful to read these roundabout accounts today. We have no land ethic yet, (47)【but we have at least drawn nearer the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us.】 A parallel situation exists in respect of predatory mammals and fish-eating birds. (48)【Time was when biologists somewhat overworked the evidence that these creatures preserve the health of game by killing the physically weak, or that they prey only on “worthless” species.】 Here again, the evidence had to be economic in order to be valid. It is only in recent years that we hear the more honest argument that predators are members of the community, and that no special interest has the right to exterminate them for the sake of a benefit, real or fancied, to itself. Some species of trees have been “read out of the party” by economics-minded foresters because they grow too slowly, or have too low a sale vale to pay as timber crops. (49)【In Europe, where forestry is ecologically more advanced, the non-commercial tree species are recognized as members of the native forest community, to be preserved as such, within reason.】 Moreover, some have been found to have a valuable function in building up soil fertility. The interdependence of the forest and its constituent tree species, ground flora, and fauna is taken for granted. To sum up: a system of conservation based solely on economic self-interest is hopelessly lopsided. (50)【It tends to ignore, and thus eventually to eliminate, many elements in the land community that lack commercial value, but that are essential to its healthy functioning.】 It assumes, falsely, that the economic parts of the biotic clock will function without the uneconomic parts.
One basic weakness in a conservation system based wholly on economic motives is that most members of the land community have no economic value. Yet these creatures are members of the biotic community and, if its stability depends on its integrity, they are entitled to continuance. When one of these noneconomic categories is threatened and, if we happen to love it, we invert excuses to give it economic importance. At the beginning of century songbirds were supposed to be disappearing. (46)【Scientists jumped to the rescue with some distinctly shaky evidence to the effect that insects would eat us up if birds failed to control them. The evidence had to be economic in order to be valid.】 It is painful to read these roundabout accounts today. We have no land ethic yet, (47)【but we have at least drawn nearer the point of admitting that birds should continue as a matter of intrinsic right, regardless of the presence or absence of economic advantage to us.】 A parallel situation exists in respect of predatory mammals and fish-eating birds. (48)【Time was when biologists somewhat overworked the evidence that these creatures preserve the health of game by killing the physically weak, or that they prey only on “worthless” species.】 Here again, the evidence had to be economic in order to be valid. It is only in recent years that we hear the more honest argument that predators are members of the community, and that no special interest has the right to exterminate them for the sake of a benefit, real or fancied, to itself. Some species of trees have been “read out of the party” by economics-minded foresters because they grow too slowly, or have too low a sale vale to pay as timber crops. (49)【In Europe, where forestry is ecologically more advanced, the non-commercial tree species are recognized as members of the native forest community, to be preserved as such, within reason.】 Moreover, some have been found to have a valuable function in building up soil fertility. The interdependence of the forest and its constituent tree species, ground flora, and fauna is taken for granted. To sum up: a system of conservation based solely on economic self-interest is hopelessly lopsided. (50)【It tends to ignore, and thus eventually to eliminate, many elements in the land community that lack commercial value, but that are essential to its healthy functioning.】 It assumes, falsely, that the economic parts of the biotic clock will function without the uneconomic parts.
题目解答
答案
参考译文46. 科学家们迅速出手拯救它们，并提出了不可信的证据，声称如果鸟儿不能控制昆虫的数量，昆虫就会把我们吃光。47. 但我们至少近乎承认，不论鸟类对我们是否有经济利益，它们都应该持续存在，这是一个自身固有权利的问题。48. 曾几何时，生物学家们总是滥用这一证据：这些生物通过捕食体弱的生物来维系健康的生物链，或者说它们仅仅捕食“无价值”的物种。49. 在欧洲，生态林业较为发达，那些没有商业价值的树种被视为本地森林群落的成员，应该得到合理保护。50. 这种保护系统往往忽视并因此最终消灭那些缺乏商业价值，但对其健康运转至关重要的物种。
解析
文章讨论了基于经济动机的保护系统的一个基本弱点，即大多数土地社区的成员没有经济价值。然而，这些生物是生物群落的成员，如果其稳定性取决于其完整性，它们应该继续存在。当这些无经济价值的类别受到威胁时，如果人们喜欢它们，就会提出一些借口来赋予它们经济重要性。
步骤 2：分析句子 (46)
科学家们迅速出手拯救它们，并提出了不可信的证据，声称如果鸟儿不能控制昆虫的数量，昆虫就会把我们吃光。证据必须具有经济价值才能被认为是有效的。
步骤 3：分析句子 (47)
但我们至少近乎承认，不论鸟类对我们是否有经济利益，它们都应该持续存在，这是一个自身固有权利的问题。
步骤 4：分析句子 (48)
曾几何时，生物学家们总是滥用这一证据：这些生物通过捕食体弱的生物来维系健康的生物链，或者说它们仅仅捕食“无价值”的物种。证据必须具有经济价值才能被认为是有效的。
步骤 5：分析句子 (49)
在欧洲，生态林业较为发达，那些没有商业价值的树种被视为本地森林群落的成员，应该得到合理保护。此外，一些树种在提高土壤肥力方面具有重要作用。
步骤 6：分析句子 (50)
这种保护系统往往忽视并因此最终消灭那些缺乏商业价值，但对其健康运转至关重要的物种。