Falling leaves
Leaves are the powerhouses of trees. A mature oak tree has around 700,000 leaves, providing food for the tree and enough oxygen for 10 people for a year.
As leaves start to die in autumn, the tree takes back reusable proteins and green chlorophyll. This reveals the yellow and red pigments produced by sugars remaining in the leaf. The best and most long-lasting colours develop with warm, bright days and cold nights, slowing the transport of sugar from the leaf.
Try and catch a falling leaf on your autumn walk, it’s trickier than you think.
Fungi
As the leaves disappear, you start to notice everything else that lives in the woodland - mosses, lichens and fungi.
Fungi don’t have chlorophyll, so they can’t make their own food like trees. They break down plant matter into simple substances they can feed on. Without fungi, the world would choke on its own waste.
Oak and birch trees are good places to look for fungi. (Look, but don't eat, and wash your hands after touching). The classic red and white spotted toadstool (Fly Agaric) is often spotted near a birch.
Bracket fungi gain height to spread their spores further by attaching to the trunk of a tree. Cup fungi such as the orange peel fungus shoot spores out like bullets from microscopic guns - you can sometimes hear the pop. Puff balls (like soft footballs on the ground) release spores like puffs of smoke when rain drops hit them.