About five percent of it by weight was made of living things, and this critical five percent consisted of dense populations of nematodes, worms, mollusks, arthropods, insects, arachnids, small mammals, fungi, protozoa, algae, and bacteria. The bacteria alone included several thousand different species, and could number as high as a hundred million individuals per gram of soil. And the other members of the microcommunity were almost as plentiful, in both number and variety.
