All living things need food

Knowledge pool
Habitats - in fields and meadows

  • A wasp spider waits in its web for prey (source: E. Oppermann)

When an organism ingests food, a large part of the energy it contains is used up for heat production and metabolic processes. At the end of the food chain, therefore, only a fraction of the energy that was originally provided by the primary producers reaches the end of the food chain. In short, the energy content within an ecosystem usually decreases from the bottom up, so it could be represented in the form of a pyramid. That is why there are far fewer members at the top of the food chain than at the bottom (many mice, few foxes). This is also the reason why far more people can be fed with plant foods than with meat. Because the meat of the animals, so z. B. cattle and pigs, could only arise when they ate and digested a huge amount of plants - with a corresponding loss of energy.

Typical links in a food chain in the "fields and meadows" ecosystem:

● Primary producers: grasses, herbs, flowers, bushes
● Primary consumers: grasshoppers, insect larvae, mice, grain-eating birds
● Secondary consumers: hedgehogs, martens, insectivorous birds, birds of prey, fox

The example of the fox shows how fluid the transitions between the links of a food chain can be. On the one hand, the fox is at the top of the food chain, as it is one of the largest predators in our fauna. On the other hand, it feeds on very different "chain links" such as mice and insect larvae, but also earthworms and berries or fruits. It is therefore at the same time primary and secondary consumer and can even become prey of higher-standing predators (e.g. young foxes are sometimes the victims of an eagle).