THE STRONG OAK
Oaks have the hardest wood of our native trees.
Unfortunately, this is not quite true. With regard to their resistance to pressure, oaks are not able to compete with the hard wood of hornbeams – if only slightly. Beeches have the additional bonus that they are easier to work due to their smooth wood structure. However, oak wood is extremely weather-resistant. Therefore it is no surprise that Hamburg’s Speicherstadt (warehouse district) has been resting for more than 100 years on a foundation of more than 3 million oak trunks which were driven deep into the mud.
WOOD CAN FLOAT ON WATER!
Wood can float on water.
This is mostly true, but not always. The Brazilian ironwood tree for example does not behave like you would expect wood to behave at all. If you throw a piece of ironwood into the water, it sinks like a stone. This is due to the enormous density of the wood. It weighs more than the displaced water and is therefore unable to stay at the surface.
But there is also an indigenous shrub that is a non-swimmer: The Cornelian cherry (Cornus mas). The shrubs that can reach a height of up to 8 meters have the heaviest wood in Europe, but are irrelevant for the timber industry. Only the fruits are used for fruit spirit or jam (they are 10 times richer in vitamin C than lemons!).
CONIFERS ARE EVERGREEN
For most people, spruces and firs are the epitome of conifers – and of course they are evergreen. However, this is not always the case. There are conifers that shed their needles each fall like broadleaf trees. This includes the giant redwood tree of virgin forests just like our indigenous larch tree. Evergreen conifers have an advantage over the broadleaves: They do not have to invest energy in forming leaves in spring, but can start with photosynthesis straight away.
As a consequence, in the far north, only conifers will grow from a certain latitude. The summers are simply too short to start leaf production in spring. However, the needles are subject to constant evaporation in winter. To avoid dying of thirst, conifers have special plugs in their capillaries to prevent the unimpeded loss of water.