La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Factors influencing the supply of tree cavities and the effects of supply on species composition and population density of cavity breeders in montane forests
Auteurs :	Anna Kanold, Auteur ; Nils Rohrmann, Auteur ; Joerg Mueller, Auteur
Type de document :	Article
Dans :	Ornithologischer Anzeiger (47(2-3) DEC 2008)
Article en page(s) :	116-129
Résumé :	To find out more about factors which influence cavities in trees, all such holes were recorded along five transects covering 293 hectares in the Bavarian Forest National Park. Age of woodland and amount of dead wood were found to be positive parameters and density of roads/paths and altitude to be negative parameters. In the montane mixed woodland zone, analysis of management types indicated significantly higher numbers of cavities in old woods and in non-intervention trial areas compared with managed areas. At higher altitudes also, supply of cavities is better in nonintervention areas. Use of a regression tree showed that presence of 5 cavities per hectare led to approximately double the number of cavity-breeding species. The analyses substantiate not just the outstanding role of old woods in providing an abundance of cavities, but also that of the non-intervention areas. Although management in the latter stopped only a few decades ago, they are developing into natural woods, with better conditions for woodpeckers and cavity-breeders.

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