Secrets in a Tree's Rings: What They Can Tell Us! 🌳🕵️‍♂️

How are the annual rings of trees formed? And what do they tell us about the past? Every year a tree forms a new growth layer. Therefore, the more rings the tree has, the older it is. The reason for this is the seasons. In the spring, the tree grows the fastest. During this time, he forms the light layer of a ring. In autumn, he grows more slowly - the dark layer is formed. It's too cold in winter. That's why a growth pause is called for. But that's not all: because the rings tell us even more than just the age of a tree. They are also an archive for the conditions under which he grew.
If the tree gets enough light, water and nutrients in a year, and favorable temperatures prevail, it will grow faster. Then he forms more wood - that is, a wider ring. But it may also be that the tree is disturbed during growth. For example, when it rains too little and is very hot. Then he forms only a narrow ring. Therefore, by the sequence of the rings, one can accurately determine the age of wood - even centuries after a tree was felled. And you can say exactly when the tree lived and in what year it was felled. This is also how the age of historical buildings can be determined. For this purpose, the annual rings of the wooden beams with which the building was built are examined.
ZDF/TerraX/Leon Altfeld/Julia Bruch/Maximilian Heß