CoachThe food web of a habitat is the network of all its food chains at once: every species drawn once, with an arrow (still meaning is eaten by, Remark 19.2) for every meal relationship. Most animals eat several species and are eaten by several — so the chains cross, and the drawing becomes a web.
示例
Example 34.2 (Reading the web)
Two readings of the figure. Follow the rabbit’s arrows: it eats grass and clover, and is eaten by fox and buzzard — four relationships, where a chain showed two. And count the buzzard’s food arrows: lizard and rabbit — lose one, the other remains. The web records exactly the spare options that Proposition 30.5 praised.