Wohlleben’s main idea in this chapter is how trees can create their own microclimate. He explains that deciduous trees create a leafy humus that can store moisture, and their branches can slow winds and create a calmer air within the forest. Over time, these conditions reduce evaporation and create moist soil with better water storage, allowing more trees to thrive.

Wohlleben specifies that there are differences between how human managed forests and old growth forests can manage these microclimates. He cites a university study which found that during a heatwave the undisturbed forest remained much cooler than the managed forest. The author attributes this difference to the greater total biomass in the undisturbed forest—since dead wood was left in place, it provided shade and protection to the humus, and prevented its moisture from evaporating in the hot sun.

The author then analyzes another “climate control” technique: water storage. He writes that beech trees can angle their branches during heavy rainfall to direct water towards their trunks, where it will run down to their roots. He contrasts this example with the spruce tree, which is hardly able to receive rainfall at all, since their needled umbrella crowns shade them so thoroughly. Wohlleben notes that these trees, and other conifers, are not native to many places in Europe and were planted for commercial reasons.