What is the meaning of living beings

Organisms that live permanently in the soil are called soil organisms. As a rule, they are so small that they can hardly be seen or not at all with the naked eye, and they are extremely numerous in the soil. These soil organisms are characterized by a large variety of species and forms. These include, for example, bacteria, protozoa, fungi, algae, worms, crustaceans, arachnids, millipedes and numerous insect orders (see species richness and diversity of forms of soil organisms).

In a handful of soil, there are numerically more soil organisms than there are humans on earth. Depending on the quality of the soil, up to 10 billion soil organisms can be found in a soil cube with an edge length of 10 cm. Nevertheless, the weight percentage of all organisms permanently living in the soil is less than 1% of the total soil substance (see Fig. 1). This shows how small these organisms are.

Composition of the soil substance (approx. 50% of the soil body)

At the beginning of the 20th century, the biologist Raoul Francé coined the term "Edaphon" (edaphos (Greek) = ground). The Edaphon can be subdivided into soil flora and soil fauna. By definition, the subterranean organs of the plants rooted in the ground are not counted as part of the Edaphon.

The soil flora mainly includes plant or non-animal organisms such as bacteria, radiation fungi, fungi, algae and lichens (see soil flora). They are significantly involved in decomposition and mineralization processes and make up the main bulk of the Edaphon. Their share is 60-90% depending on the type of soil.

The soil fauna is made up of animal protozoa and multicellular organisms (see soil animals), which are differentiated according to their size into microfauna (<0.2 mm; e.g. ciliate animals, flagellates, amoebas, small nematodes), mesofauna (<2 mm; e.g. Springtails, rotifers, mites), macrofauna (> 2 mm; e.g. bristle worms, woodlice, insects) and megafauna (> 20 mm; e.g. vertebrates such as voles, shrews, moles).

Additional Information:


BRAUNS, A. (1968): Practical Soil Biology. Stuttgart: G. Fischer.
DUNGER, W. (1964): Animals in the soil. Wittenberg: A. Ziemsen.
GISI, U. / SCHENKER, R. / STADELMANN, F.X./ STICHER, H. (1997): Soil Ecology. 2nd Edition. Stuttgart; New York: Thieme.
HINTERMAIER-ERHARD. G. / ZECH W. (1997): Dictionary of Soil Science. Stuttgart: Enke
SCHROEDER, D. (1992): Soil Science in Key Words. 5th edition. Berlin; Stuttgart: Bornträger.
TRAUTZ, D. (1992): Soils as a habitat for organisms. In: Blume, H.P. (Ed.) (1992): Handbuch des Bodenenschutz. 2nd Edition. Landsberg / Lech: ecomed, pp. 58-71