(1) There is no waste in a forest because waste created is bio-degradable, which gets converted to humus by the action of microorganisms.
(2) This humus ensures that the nutrients are returned back to the soil.
(3) Whatever is produced in the forest is ultimately utilized by different components of the forest.
(4) There is a food chain in every ecosystem.
(5) Forests maintain a network of food chains called the food web and hence nothing goes to waste in a forest.