Dr. Ricarda Lehmitz
Dipl.-Biol. Franz Horak
Institution: Senckenberg Museum für Naturkunde Görlitz
Staatliches Museum für Naturkunde Karlsruhe
Oribatid mites (also known as moss or beetle mites) form a suborder of mites (Arachnida: Acari: Oribatida) with more than 9,000 known species. Within Germany more than 630 species have been identified thus far. They live in litter and humus layers of soil, particulary in forests, where more than 90 species and 100,000 individuals per square meter can be found. They are also frequently found in grasslands, field margins, as well as freshwater and semi-aquatic habitats, each with up to 50 species. The common name moss mites derives from special Oribatida communities in microhabitats such as moss and lichens on tree trunks and stones.
Within the soil fauna, moss mites play a prominent role in the decomposers / saprophyte food web due to their high population densities. They are ecologically and nutritionally classified as fungi- and detritivor (saprophagous). However, they can also live necro-/ coprophagously, and a few predatory species are known.
Oribatid mites belong to the mesofauna with a body size between 0.14 to 2 mm. Their sampling is relatively easy using standardized methods. Preparation and determination, however, require a high expenditure of time, expertise and experience. Already in the 1920s usefull data were generated for Germany and adjacent areas and have been used within EDAPHOBASE.
The presence of Oribatida species at a specific site is determined by mainly habitat type, land use (forest, grassland, arable land), climatic conditions, moisture, pH-value, nutritional value and humus content of the soil. Thus single Oribatida species or species-groups can indicate specific location factors or conditions. Providing sufficient sampling, one can identify differential or indicator species when the species composition of the Oribatida community of a site and the community structure (abundance, dominance, continuity) is known.