Veteran trees offer varied habitats for many organisms.
On a dying wood is attached a number of organisms: mushrooms, mosses, lichens, gastropods, arthropods and vertebrates. Around 3000 of our insect species are among the organisms bound to dying wood. A single old tree can host thousands of individuals of tens to hundreds of rare species. Exposure to sunlight, degree of decomposition, or the type of fungus involved in the decomposition is more important to many deadwood dwellers than the original species of wood.
In trees in the late stage of maturity, the primary crown gradually dies and at the same time its dimensions are reduced. In this period, there are practically no trees without extensive colonization of the trunk by wood-rotting fungi. It is interesting that the decay of the trunk and skeletal branches cannot be considered a fundamentally negative factorin terms of the tree’s lifespan or in terms of its static conditions.
Such trees are significant in that they simultaneously contain a wide range of habitats, typical of both living and dead trees. The veteran has cavities, so it is also a hollow tree. At the same time, it offers wood that is honestly dead, older and heavily weathered. Different, specialized organisms are bound to each of these phases of wood decomposition. One „proper“ veteran tree can therefore host a very wide range of different animals, fungi, lichens and mosses. The environment of veteran trees is often unique and irreplaceable. The preservation of such trees is for organisms bound to them a matter of survival or extinction.
Literature:
- Read, H.: Veteran Trees: A guide to good management. English Nature, 2000
- Wessolly, Erb: Manual of tree statics and tree inspection. Berlin 2016
Hollow trees contain cavities. These are created either by the action of fungi, i.e. by rotting or by pecking by woodpeckers. Many birds nest in the cavities, they are used by bats, dormice, squirrels and martens. Cavities are also home to ants, wasps and hornets, a number of endangered beetles, but also spiders or scorpions. Hollows in trees cannot be replaced with birdhouses, they are not suitable for most invertebrates, but some bird species will not accept them either. Many species also need trees in the sun, hollow trees are therefore very important for natural diversity not only in forests, but also in gardens, parks and along roads.
In cavities of hollow trees we can find Great Spotted Woodpeckers, Great Tits, Athenes, European Green Woodpeckers, Black Woodpeckers, Anthipeses, Sittas, Tawny Owls and Jynxes. Apart from birds in hollow trees we can also find squirrels, Apodemuses, bats, Dryomyses, Muscardinuses and large palet of insect species, in terms of beetles we cand find here Oxythyreas, Osmodermas, Athouses or Opatrumes.
It is a living tree that is under pressure from most external conditions. This process is not irreversible. A weakened tree may be the result of drought or a mild winter. Weakened trees have a harder time resisting colonization (for example by insects). Insects typical of this stage tend to be specialized for development under the bark or at the interface between live and dead wood. Typical inhabitants are many Jewel Beetles, Longhorn Beetles, Bark Beetles or variegated Trichodes.
Unlike weakened trees, dying trees show irreversible weakening. It can be a severe drying out of the crown, as well as a massive attack by plant (semi)parasites. A typical example can be mistletoe. Typical inhabitants are many Jewel Beetles, Longhorn Beetles, Bark Beetles or Trichodes.
0 – 2 years after „the fall“
In this category we can find freshly felled trees, freshly broken branches,… This is a dead tree (or parts of it), which still takes some time for its sap to dry. At this stage, we can talk about trees up to two years after death or felling. On this stage are tied for example Jewel Beetles, Longhorn Beetles, Bark Beetles or Trichodes.
2 – 4 years after „the fall“
At this stage, the wood no longer has sap and the bark and the bast are dry. However, the wood is still solid and without major signs of rot, the fungi are only occupying it and growing through it. For this phase, suitable wood species include, for example, Longhorn Beetles, Jewel Beetles, or Hemicoelus.
4 – 6 years after „the fall“
This stage of decay can be recognized by the fact that the bark of the tree can be easily peeled off, in some places it is completely missing. Wood loses its strength due to intensive fungal attack. Most often, this is wood lying on the ground or standing stumps. This stage is sought after by Sinoderons, Athouses or Oryctes.
more than 6 years after „the fall“
The wood is already soft, strongly rotting and falling apart. There is a layer of humus under the bark and in the wood, earthworms appear. Logs lying on the ground may be overgrown with vegetation. A typical inhabitant of such wood is Rhysodes sulcatus, but we also find Athouses and a number of other species in it.