What is Soil Life?
There are between 100 billion and 3 trillion organisms in very kilogram of fertile soil, most of it bacteria. The soil is a thin layer of perpetually decaying organic matter that covers much of the Earth. Within the soil, organisms break down dead organisms into their constituent elements, ready to be reabsorbed by plants. Without soil life, new generations of plants would be unable to recycle the biomass of the last generation, and life on Earth as a whole would cease. Soil life is generally classified by its size. At the top of the food chain are the megafauna, greater than 20 mm in size: moles, rabbits, and rodents. Below them are the macrofauna, ranging in size from 2-20 mm: woodlice, earthworms, centipedes, snails, beetles, slugs, ants, and harvestmen. Then are the mesofauna, ranging in size from 100 microns-2 mm: tardigrades, mites and springtails. The smallest are microfauna and microflora, with a size range between 1-100 micrometers: yeasts, bacteria, fungi, protozoa, roundworm
