Hollow oak – a habitat with diverse lifeforms

The Norwegian oaks are among the country’s oldest living creatures – it is said that the oak lives for 500 years and dies for 500 years. Large old oak trees consist of both fresh and dead branches, parts of dead wood, coarse sapwood and cavities. These are ideal habitats for, among other things, insects, fungi and lichens. The trees are thus home to a very large variety of species, which work together to break down the tree. In a single ancient hollow oak, one can find as many as 1,500 different species, and there may be more living individuals in just one oak than there are people living in the city of Oslo! Oak is therefore the most important type of wood for many decomposer species.

Hollow oaks are so important and rich in species that they in Norway are given special protection through the National Diversity Act. Several species that live in the oaks are very rare and will possibly only survive in old oak trees. The old, hollow oaks are unfortunately in decline across Europe, and it is therefore important that we take care of the few that are left.

Sources: 

Direktoratet for naturforvaltning 2012. Handlingsplan for utvalgt naturtype hule eiker 

www.hule-eiker.no