2025/06/16 by Hohberg, Karin, Ristok, Christian, Eisenhauer, Nico +2
#Biodiversity trend #Red lists #biodiversity change #soil animals #soil fauna #soil microorganisms #spatial biodiversity distribution
paper · doi:10.25674/449
Soils are among the habitats with the most species-rich communities on our planet. However, knowledge about soil biodiversity status and trends varies by organism group and this also applies to Germany. For soil microorganisms and microfauna, only a fraction of the expected number of species has been described so far. For most groups of soil mesofauna, including collembolans, oribatid mites, and enchytraeids checklists exist, but yet undescribed and cryptic species are to be expected, and data on the distribution and trends of taxa are missing. Larger animals belonging to the soil macrofauna, including earthworms, millipedes, centipedes, ants, isopods, ground beetles, and spiders, are better studied, and checklists and Red Lists exist in Germany. However, even in these rather well-studied groups, genetic information is limited and population trends for species remain largely unknown due to the lack of long-term, large-scale monitoring programs. Only few soil animal groups have been sufficiently studied to allow conclusions on their regional distribution and the degree of endemism or the distribution of possible neobiota. At the national, European, and global scale, data on soil biodiversity in space and time is very patchy and inconsistent. We therefore also lack baseline values to record and assess potential changes that are currently taking place. Moreover, soils are heterogeneous, varying spatially and temporally, and soil biodiversity distribution is influenced by the dynamics of resources and habitat characteristics. Spatial variation in the presence of soil animals depends on microhabitat structure, animal body size, animal mobility, and dispersal. At small scales, the physical structure and pore space of the soil play an essential role for soil organisms and their interactions. At larger scales, different habitat types contribute to soil biodiversity, with geological substrate playing a key role. Compared to aboveground communities, soil biota are more buffered against climatic fluctuations and climate change effects are thus likely to be less pronounced and delayed. Even in a rather well-studied country like Germany, our understanding of the status and trends of soil biodiversity is still scarce and we urgently need research initiatives of taxonomists, soil ecologists, data scientists and molecular biologists who jointly discover and monitor soil biodiversity and predict possible spatio-temporal changes and their consequences.