The forest is generally referred to as a primary producer, processing carbon into carbohydrates. All green plants, including those outside forests, are primary producers; it is often better to refer to the primary producers of the forest as the production ecosystem of the forest, or simply the production ecosystem. This allows us to distinguish it from other forest ecosystems. As leaves and twigs fall to the ground they build up a detritus of leaf mould which is sporadically added to by falling branches and trees, and by the decay of ferns, mosses, lichens, birds, insects and other ground dwellers.
Within this detritus there exists another forest community, the soil and litter community of decomposers which forms a distinct but vital ecosystem, the litter ecosystem, intimately linked with and supplementary to the production ecosystem itself. These two systems together formed the forest ecosystem, which can continue to function indefinitely only when these two systems are intact and fully functional. Other systems within the forest -including birds, insects and other forms of wildlife – are supplementary to the production and litter ecosystems.
The litter ecosystem consists of soil and forest to drivers together with its inhabitants. This assemblage of mostly tiny living things within the litter layer is vast and counts its population is in hundreds of thousands per hectare, for mites and small insects, and in billions for bacteria. It forms a recycling system returning into circulation vital substances used by living things as they die so that new life can use these again. This litter ecosystem is absolutely vital to the health and well-being of any forest. When it is destroyed by man or by other causes such as the trampling of animals the forest slowly dies.