Nutrient cycling is an important process for keeping ecosystems in balance because it replenishes the nutrients used by plants. Organisms that live in the soil play a major role in nutrient cycling by breaking down organic matter (dead plants and animal matter) into inorganic nutrients, which is used by plants fix growth.
Micro-organisms such as some bacteria and fungi use organic matter as a source of their own nutrients. As they decompose organic material, they release nutrients into the soil in forms that other organisms such as plants can use. This process of converting organic nutrients into inorganic nutrients is called mineralization.
Larger soil organisms such as earthworms and mites play a role in this process by reducing organic matter to smaller segments that arc easier for microorganisms to decompose. Soil organisms make up only a small amount of the organic material in soil but they still equate to hundreds of kilograms per hectare.
The range of organisms in the soil community is diverse and they interact in many ways. For example, as earthworms and mites break down organic matter into smaller segments, which arc more easily colonized by bacteria and fungi, other soil animals feed on these bacteria and fungi.
So as the population of one group of organisms increases, another will also increase and keep the number in check. After the organic material can no longer sustain growth of the first organism, the second group declines because its food supply is restricted.
A recent study found up to 23 Oribatid soil mite species in some soils. In contrast, only six spccics were found in a study of West Australian soils. This difference may be due to a difference in soil type and climate.