11 – ‘Apartments’ in forest

Old, spreading trees play a special role in the life of the forest. Most of all, they might be compared to an apartment block, since a single tree provides home and shelter for many creatures. Beside the holes formed by natural rot and woodpecker-made cavities, many so-called microhabitats (smaller habitats that characteristically stand out from their surroundings) can be found on an old tree. A loose bark, a broken branch, a trunk cavity at the ground or a dendrotelm (cavity filled with water) are examples of microhabitats that can be commonly observed. The inhabitants are as diverse as the habitats they settle. But they have one thing in common: they are sentenced to death in the absence of hosting old trees. Let’s get to know these lurking lodgers!

Decaying old beech with several microhabitats.

The Berlin jewel beetle lives in barkless trees. It chooses only standing deadwood for laying eggs, regardless of the species. It can develop either in beech, hornbeam, and other tree species. (Author: Diána Balogh, source: izeltlabuak.hu, licence: CC BY 4.0)

Basal tree hollows are one of the most important microhabitats.

The violet click beetle is a rare and protected resident of basal tree hollows. It is native mainly to oak forests, where the following conditions exist. Inside the cavity, just below wood mould, the soil must be saturated with humic and tannic acids, easy to be fractured. The larvae live in the wood mould mixture, feeding on the organic materials.

Incredibly, the fire salamander also requires microhabitats of dead wood. This protected amphibian finds excellent shelters under decomposing logs and in humid trunk cavities. (Author: Danny S., source: Wikimedia Commons, licence: CC BY-SA 3.0)

Dendrotelms provide habitat for dozens of small creatures.

The knothole moss can be found on the edge of turkey oak dendrotelms. This bryophyte is a rare and endangered moss in Europe. Only a few mid-mountain localities are known from Hungary. (Author: Blanka Aguero, source: bryophyteportal.org)

Did you know?
The barbastelle bat is a rare and strictly protected inhabitant of Hungarian semi-natural forests. Due to its special habitat needs, this species is endangered throughout Europe. An adequate number of large, dying and dead trees in the forest is necessary, since it roosts mainly under stripping bark. It is a medium-sized (4–6 cm large) bat with a characteristic pug-shaped nose.

Barbastelle bats usually dwell under loose bark.

Barbastelle bat