Trophic levels

Ecology · Trophic levels in an ecosystem · note 1 of 3

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Trophic levelsSpec 4.7.4.1

Trophic levels can be represented by numbers, starting at level 1 with plants and algae. Further trophic levels are numbered subsequently according to how far the organism is along the food chain.

Trophic level	Organisms	Name
Level 1	Plants and algae make their own food	Producers
Level 2	Herbivores eat plants and algae	Primary consumers
Level 3	Carnivores that eat herbivores	Secondary consumers
Level 4	Carnivores that eat other carnivores	Tertiary consumers

Apex predators are carnivores with no predators.

Decomposers

Decomposers break down dead plant and animal matter by secreting enzymes into the environment. Small soluble food molecules then diffuse into the microorganism.

Food chain of grass, grasshopper, frog and snake labelled trophic levels 1 to 4, with dashed arrows from each to dead plants and animals and their waste; below, decomposers (microorganisms) secrete enzymes onto the dead material and small soluble food molecules diffuse into them. — Every trophic level ends up as dead material or waste. Decomposers secrete enzymes onto it, then the small soluble molecules diffuse in.