CoachThe web’s species sort into roles:
- the producers: the plants, which make their own matter (Proposition 22.6) — every arrow-path starts on one (Proposition 19.3);
- the consumers: the animals, living on others — herbivores eating producers directly, carnivores eating other consumers, omnivores both (Definition 10.1);
- and, working in the shadows, the decomposers — the rotters of Example 13.9, who feed on dead remains and return their substance to the soil. A later year gives them their own chapter.
示例
Example 34.4 (Sorting the figure)
In the pocket web: producers — grass, clover, oak; herbivorous consumers — grasshopper, rabbit, caterpillar; carnivorous consumers — lizard, blue tit (mostly), fox (an omnivore in truth), buzzard, sparrowhawk. Three floors: green, plant-eating, meat-eating — with every upper floor standing on the ones below.