Die Bedeutung von Alt- und Totholz fuer unsere Spechte

1993

S. 157-162

7 Lit. Ang.

Unselbständiges Werk

200097898

Woodpeckers rely on wood especially on types of old wood (Altholz) und dead wood. This is true for nearly all functional cycles: foraging (wood as substrate for the prey, anvil and food storages); for roosting (roosting holes); for reproduction (nest hole in trunk and branch); intra- and interspecific communication (drumming and tapping) and for thwarting situations (pecking as displacement activity). The population density of some woodpecker species in the woods and territory size depends on the availability of food in old and dead wood. The more old and dead wood (logs, stumps, stubs), the higher the population density of particular woodpecker species respectively the smaller the territory size (e.g. Dryocopus). A greater cover of overstore canopy strengthens this effect. On the one hand there is a positive correlation between the canopy cover and the food supply, and on the other hand a negative correlation between percentage of canopy cover and the size of woodpecker territories. The woodpeckers utilize the available food, when there is a sufficient offer of holes or potential holes. This is a highly limiting factor. To a certain extent woodpeckers manage their hole supply themselves. Through building of holes woodpeckers have a key role for other animals, who use holes. In the same way the woodpeckers perform a vital function for decomposing organisms of wood recycling, through their hacking activities on stumps and trunks. In connection with hole management, the fact is that hole trees are rarely isolated in the wood but in groups, forming centres of hole trees (Hoehlenzentren). This is dependent on several factors (high motivation of hacking and hole building near hole trees, habitat or environment with atmospheric conditions, forest management). Protection of woodpeckers is only possible with a combination of species conservation and biotope conservation. In this context it is important to say to the public, that the cleared forest (aufgeraeumter Wald = neatly groomed) is no longer the ideal of forestry, or at least shouldn't be.