Wie tief ist der Boden? Von belebten Strukturen und Kreaturen des Untergrunds

Abstract

The biologically active part of the earth‘s upper crust is not limited to a layer of the earth‘s surface only a few meters thick but extends much more heterogeneously in its vertical dimension. It extends locally down to a depth of 2 kilometres or more in caves and, in any case, several decametres through gaps, fissures, and crevices. With numerous examples from several continents, this article provides an insight into the diversity of subterranean habitats and the species that colonize them. The term „soil“ is interpreted broadly and discussed in the context of the subterranean part of the Earth‘s „critical zone“. Reference is also made to the potential refugial and corridor function of subterranean habitats in the context of climate change. Soil protection and the protection of subterranean habitats must be considered in a more differentiated and broader way than the „classic“ view, which often focuses on productive, biomass-rich, habitats that are preferred by higher plants. Extreme site conditions often play an important role for biodiversity on the soil, in its uppermost layers and in the „deep soil“; without or with only low suitability for higher plants and without accumulation of biomass, partly also with a dynamic through recurring processes that interrupt soil succession in small (mosaic-like) or large areas. In any case, in terms of biodiversity, this must be given equal consideration or case-by-case, and area-by-area, even priority over other possible soil functions