The ‘Internet’ of the forest




The Internet of the forest

The ‘Internet’ of the forest

The widely ramified root system of a sweet chestnut tree stands here as an example of the ‘Wood Wide Web’, the interconnecting system of highly diverse and occasionally the very smallest forms of life that during the course of evolution have adapted themselves to their particular habitat in the forest. Material is utilized and transformed, ensuring ecological balance. However, this balance is critically endangered by far-reaching climatic changes.

Strong roots

Roots like those of the sweet chestnut not only anchor trees in the soil but also play a major role in supplying the plants with nourishment. Most of the root body lies underground, where fungi and bacteria foster the uptake of nutrients and enable the trees to connect and communicate with one another.

Dying sweet chestnut tree

The trunk of a sweet chestnut infected with chestnut blight stands here for the threat to native plant species posed by imported pathogens and illustrates the vulnerability of ecosystems. Originating in East Asia, this fungus destroyed almost all the sweet chestnut in the Eastern USA in the first half of the twentieth century, later also spreading to Europe. Here, however, the effects of the disease have been less dramatic, since the European sweet chestnuts appear to be naturally more resistant, and in the meantime biological control methods have been developed to combat this aggressive fungus.

Dynamic liana

Traveller’s joy or old man’s beard is a European member of the botanical family of lianas. It mostly grows inconspicuously at the edge of wooded areas and in clearings, or scrambles over shrubs. If the soil conditions are moist enough it can grow to a length of ten metres, penetrating the crowns of trees.

Partnership for survival

Lichens represent a successful symbiosis of fungi and algae: the fungus is able to absorb water and minerals, providing protection from dehydration and mechanical damage, while the alga produces sugars with the aid of carbon dioxide, water and energy from the sun (photosynthesis).

Long-distance wanderers and devoted mothers

The powerful and imposing brown bear inhabits wide regions of Europe, and it is not uncommon for young bears searching for their own home range to cover hundreds of kilometres. Mothers are exclusively responsible for parenting their young, which they usually keep close to them.

Nocturnal in habit, brown bears are omnivores, feeding mainly on plants, fungi and tubers, but also slugs and snails, amphibians, birds, small mammals, insects and honey. Conflict with humans can arise when bears kill sheep or raid bee hives. Nowadays such losses are compensated from state funds made available for damage caused by game or wild animals.


The common juniper is widespread in Carinthia: on the tree line it grows as a low recumbent shrub, while in valleys it mostly forms small multi-stemmed trees. The pieces of trunk displayed here are from a remarkably large specimen from Globasnitz in Lower Carinthia.

Colourful bird

The greater spotted woodpecker is the commonest type of woodpecker occurring in Carinthia. It has black and white plumage with characteristic reddish colouring at the neck (male) and the root of the tail (female). The original habitat of the greater spotted woodpecker is deciduous and coniferous forest. However, it also uses the thermal insulation facades of residential buildings as a sound box to communicate in the mating season and to make its nest cavities, which once abandoned can be used by other animals.

Greater spotted woodpeckers can be frequently observed ‘chiselling’ out insect larvae from the bark of diseased or dead trees. However, they also eat seeds, berries and fruits as well as the nestlings of songbirds.

A tiny pest with a huge impact

Although the typographer is minuscule, forestry workers in Austria fear it as one of the few harmful types of bark beetle that can multiply rapidly, particularly in spruce monocultures. Here they tend to infest trees that are already weakened, boring their breeding galleries underneath the bark. Larvae, pupae and young beetles also overwinter there, while the adult beetles seek shelter on the forest floor. Its natural enemies are flies, wasps and other beetles. Birds and fungal infections can also negatively affect bark beetle populations. However, global warming and increasing aridity create ideal conditions for the beetle to reproduce in massive numbers.

Natural woodworkers

Tree fungi play an important part in the natural cycle in our forests. They form minuscule spores that are dispersed through the air. When these land in a suitable place, they develop into fungal tubes or hyphae that grow through the wood of diseased or dead trees. Wood consists of microscopically small cells that are enclosed by a many-layered cell wall. The carbohydrates and lignins (responsible for the brown colour of healthy timber) supply the fungus with the energy and nutrients it needs for its own growth. In this way it breaks down and utilizes dead wood, which would otherwise pile up high in the forest.

More about natural woodworkers ...

From ground to air: the storeys of the forest

Untouched forests provide their inhabitants with various habitats, which are known as ‘storeys’ or strata: from the shady forest floor and the shrub layer right up to the sunlit tree tops, these storeys are home to a multiplicity of species that have become ever better adapted to their environment over the course of evolution. Frequently a single habitat and its limited resources are shared by many different animals and plants. This results in interactions and interdependencies as well as open competition as predator and prey.

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