Station 9 - English

Small Organisms Station

Natural forests – healthy brooks

Flowing bodies of water are complex ecosystems. The composition of the immediate surroundings is also an important factor for healthy life in a brook. Deciduous trees such as alder or ash not only stabilise the banks of a brook; in summer they provide needed shade, and in winter they allow the warming rays of the sun to penetrate. Their leaves supply food, and their root structure offers hiding places for young fish and other brook inhabitants.

Health police

Numerous hiding places in a natural brook benefit freshwater crayfish, for example, which “police” the health of flowing bodies of water. Among other things, crayfish feed on dead animals, and eat decaying leaves and algae. In this way they protect the sensitive brook from eutrophication. In turn, crayfish serve as food for predatory fish, birds, and the European otter.

Lethal spruce

The banks of many sections of brooks in the National Park are still covered with spruce trees, which in fact are not native here. Their root structure does not stabilise the banks of the brooks, and they shade the flowing waters throughout the year. The fact that their needles significantly increase the acidity of the water and do not provide any suitable food for brook inhabitants is particularly harmful. Spruce trees are therefore being systematically removed from beside brooks in the National Park.

Nothing functions without small organisms

We consider ourselves lucky if we catch sight of a trout or an amphibian in a brook. However, several thousand plant and animal species inhabit the brook ecosystems of Central Europe. Some spend their whole lives in the water while others, such as dragonflies, develop there only as larvae.

Most brook inhabitants are inconspicuous small organisms. However, each has its own place in the biological communities that are of great importance for the self-purification capacity of bodies of water.

On the left side of this station is a model of a brook caddis fly larva that you can touch.

In the illustration, you can see the following animal species that live in brooks:

• Brook caddis fly larva

• Bristly caddis fly

• Golden-ringed dragonfly larva

• Two-tailed stonefly larva

• Mayfly Epeorus sylvicola

• Freshwater shrimp

• Giant lacewing

• Stonefly Perla marginata larva

• Diving beetle Platambus maculatus

• Flatworm Polycelis felina