生物多樣性小百科

生態系

　　指植物、動物及各種其他生物，與它們所在環境相互影響，所組成的單元體。

　　生態系的大小千變萬化，它可以是一整座大森林，也可以是一個小池塘。不同生態系通常以各種地理上的界線劃分為沙漠、高山、海洋等，或以其他方法區隔成湖沼或河流等類型。由於這樣的劃分界線並不是一成不變，各生態系實際上是互相交疊的，因此整個地球可以被視為一個龐大的生態系，而一個湖泊卻也可以被切成好幾個小生態系，完全取決於使用的尺度。

　　生態系中的生物，通常會與其他的生物及所在的環境達成和諧的平衡。引入新的環境因子或新的物種，可能造成災難性的後果，甚至最後導致生態系的瓦解，及當地原有物種的大量死亡。生態健康度的抽象概念就是企圖計算健全度及承載量，以重建天然的生態系。

Ecosystem

A community of organisms (plant, animal and other living organisms - also referred as biocenose) together with their environment (or biotope), functioning as a unit.

An ecosystem may be of very different size. It may be a whole forest, as well as a small pond. Different ecosystems are often separated by geographical barriers, like deserts, mountains or oceans, or are isolated otherwise, like lakes or rivers. As these borders are never rigid, ecosystems tend to blend into each other. As a result, the whole earth can be seen as a single ecosystem, or a lake can be divided into several ecosystems, depending on the used scale.

The organisms in an ecosystem are usually well balanced with each other and with their environment. Introduction of new environmental factors or new species can have disastrous results, eventually leading to the collapse of an ecosystem and the death of many of its native species. The abstract notion of ecological health attempts to measure the robustness and capacity for recovery of a natural ecosystem.