A dead oak will fall

Life flourishes in dead wood

A new network is emerging: producers, predators, parasites

The dead oak is meanwhile experiencing the second wave of colonization. Rod beetles, Schröter, black beetles and click beetles burrow through the now rotten trunk. Millipedes and woodlice crawl through the feeding tunnels - always in danger of woodpeckers and other insect hunters who now come by regularly looking for food. Parasites like the giant parasitic wasp tip over the dead wood and try to sense the vibrations of the wood wasp larvae under the bark with their antennae. If they locate a larva, they stick their laying stinger through the bark into the victim and lay their eggs in the victim's body.

Producers, predators, parasites, scavengers - the species community in dead wood forms its own food web, the diversity of which depends on various factors. The quantity and quality of the dead wood play an important role. It depends on them how much energy and nutrients are basically available. In every forest there is wood in the form of dead branches or tree stumps. However, very thick trees, which can decay over a long period of up to 80 years, are decisive for biodiversity.

Sunlight is also important. Deadwood that lies in a clearing where flowering plants also bloom usually has a higher number of fungus and animal species than a dead tree that rots in the shade. This phenomenon can be explained by the food preferences of many beetles: As soon as they have outgrown the larval stage, pollen and nectar are on their menu. Both are hard to find in shady forests.

The species community is also picky about the type of biotope wood: "The oak is considered to be the 'most species-rich' tree species. It is home to around 650 species of wood beetles, while there are 'only' 240 different beetles on the beech and just 60 on the spruce, "reports Swiss biotope wood expert Beat Wermelinger.