Forests are more than an accumulation of trees. The individual tree is more than a valuable source of wood. From its roots to its crown, it offers habitats to a variety of the most different creatures. The older a tree, the more valuable it becomes to many forest inhabitants. And even in death it is still full of life. If you take a closer look at a forest, you notice that the plants grow to different heights. They form storeys like those of a house. At the top level there are only the big trees. From a bird’s perspective we see that the highest specimens in the forest form a closed canopy. In summer, the treetops resemble big parasols shading the forest floor. Depending upon how much sunlight filters into the depths, this has consequences for the forest vegetation.