Coloured scanning electron micrograph (SEM) of white rot fungus (Antrodiella sp., yellow) on woody debris from the Northern Black forest, Germany. Fungi are the first organisms to decompose wood because they can split and utilise lignin, a complex compound in the woody cell walls of plants. Together with bacteria and microscopic animals, they form humus from organic waste. Magnification: x70 when printed at 15cm wide.