One basic weakness in a conservation system based wholly on economic motives is that most members of the land community have no economic value.

一个完全基于经济动机的环境保护制度的基本缺陷是，土地群落的绝大多数成员都没有经济价值。

Yet these creatures are members of the biotic community and, if its stability depends on its integrity, they are entitled to continuance.

然而这些生物都是生物群落中的成员，如果这个群落的稳定依赖于它自身的完整的话，那么这些动物就有权继续生存下去。

When one of these non-economic categories is threatened and, if we happen to love it, we invert excuses to give it economic importance.

当某一类没有经济价值的物种受到威胁时，如果我们恰巧喜爱他，就会编一些借口来赋予它经济重要性。

At the beginning of century songbirds were supposed to be disappearing.

本世纪初，人们普遍认为百灵鸟正在逐渐消失。

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.

科学家们急忙介入，但提出的证据显然站不住脚，其大意是，如果鸟类不能控制昆虫的数量，昆虫便会吞噬我们人类。

The evidence had to be economic in order to be valid.

证据必须是有经济价值，才能站得住脚。

It is painful to read these round about accounts today.

现在要理解这些拐弯抹角的陈述是痛苦的。

We have no land ethic yet, but we have at least drawn near 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.

虽然我们还没有土地伦理，但是我们至少都承认，无论鸟类是否来给我们经济价值，他们都有生存下去的权利。

A parallel situation exists in respect of predatory mammals and fish-eating birds.

关于肉食哺乳动物和食鱼鸟类，也存在类似的情形。

Time was when biologists somewhat over worded the evidence that these creatures preserve the health of game by killing the physically weak, or that they prey only on "worthless" species.

有证据表明：这些食物捕食体弱者，保持种群的健康。或者说它们仅仅捕食"没有价值"的物种。

Here again, the evidence had to be economic in order to be valid.

这再次证明，证据必须是经济价值，才能站得住脚。

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 benefit, real or fancied, to itself.

直到最近几年，我们才听到一种比较诚实的论点：肉食动物是土地群落的成员，任何群体都不能因为特殊利益，有权消灭它们。无论该利益是真的还是虚构的。

Some species of tree 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.

某些树种已被重视经济利益的林务官"驱逐出境"了。因为它们生长速度过慢，或作为木材收入价值太低。

In Europe, where forestry is ecologically more advanced, the non-commercial tree species are recognized as members of native forest community, to be preserved as such, within reason.

在林业生态更为发达的欧洲，没有商业价值的树种被合理地看成是当地森林群落的成员，并得到相应的保护。

Moreover some have been found to have a valuable function in building up soil fertility.

此外，有些树种在增强土壤肥沃性方面具有重要作用。

That interdependence of the forest and its constituent tree species, ground flora, and fauna is taken for granted.

森林、树种、地面植物、动物这些组成森林的因素之间相互依赖，是理所当然。

To sum up: a system of conservation based solely on economic self-interest is hopelessly lopsided.

总而言之： 一个只基于经济利己主义的环境保护制度是百分之百不公平的。

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.

这种保护体系往往忽视群落中诸多缺乏商业价值但对其健康运作至关重要的物种，从而最终导致他们的灭绝。

It assumes, falsely, I think, that the economic parts of the biotic clock will function without the uneconomic parts.

我认为他错误地假定，即使没有非经济的部分，生物中的经济部分也一样可以正常运行。