Biomass
At any one time in a habitat, the amounts of living plant and animal tissue (biomass) can be measured or estimated. In production horticulture, it is clearly desirable to have as close to 100 per cent of this biomass in the form of the primary producer (crop), with as little primary consumer (pest or disease) as possible present. On the other hand, in a natural woodland habitat, the primary producer would represent approximately 85 per cent of the biomass, the primary consumer 3 per cent, the secondary consumer 0.1 per cent and the decomposers 12 per cent. This weight relationship between different trophic levels in a habitat (particularly the first three) is often summarized in graphical form as the 'pyramid of species'.
Countryside management utilizes these succession and food-web principles when attempting to strike a balance between the production of species diversity and the maintenance of an acceptably orderly managed area.
Succession to the climax stage is often quite rapid, occurring within 20 years from the occurrence of the bare habitat. Once established, a climax community of plants and animals in a natural habitat will usually remain quite stable for many years.
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