Search

Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data., (© 2024. The Author(s).)

Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning., (© 2023. The Author(s).)

Soil food webs are driven by plant-derived carbon (C) entering the soil belowground as rhizodeposits or aboveground via leaf litter, with recent research pointing to a higher importance of the former for driving forest soil food webs. Using natural abundance stable isotopes of wheat (C3 plant) and maize (C4 plant), we followed and quantified the incorporation of shoot residue- and root-derived maize C into the soil animal food web of an arable field for 1 year, thereby disentangling the importance of shoot residue- versus root-derived resources for arable soil food webs. On average, shoot residue-derived resources only contributed less than 12% to soil arthropod body C, while incorporation of root-derived resources averaged 26% after 2 months of maize crop and increased to 32% after 1 year. However, incorporation of root-derived maize C did not consistently increase with time: rather, it increased, decreased or remained constant depending on species. Further, preference of shoot residue- or root-derived resources was also species-specific with about half the species incorporating mainly root-derived C, while only a few species preferentially incorporated shoot residue-derived C, and about 40% incorporated both shoot residue- as well as root-derived C. The results highlight the predominant importance of root-derived resources for arable soil food webs and suggest that shoot residues only form an additional resource of minor importance. Variation in the use of plant-derived C between soil arthropod species suggests that the flux of C through soil food webs of arable systems can only be disentangled by adopting a species-specific approach.

Removal of crop residues has become common practice in arable systems, however, little is known about how soil arthropod communities change in response to reduced resource availability and habitat complexity associated with residue removal. We added maize residues to wheat and maize fields and investigated soil arthropod diversity and abundance over the period of one year. Residue addition did not affect the diversity and little affected the abundance of soil arthropods in wheat and maize fields with the latter being restricted to few taxonomic groups, suggesting that at least in the short-term soil arthropods benefit little from crop residue-mediated increase in food supply and habitat structure. Contrasting the minor effects of residue addition, densities of soil arthropods were much higher in wheat than in maize fields, presumably due to more dense and more continuous coverage by plants, and higher input of root residues. Furthermore, in wheat fields density of arthropods more strongly varied with season, presumably due to more pronounced pulses of root exudates and root residues entering the soil in wheat as compared to maize fields in summer and winter, respectively. Low density and little variation in densities of soil arthropods in maize fields reflect that environmental conditions and resource supply varied little with crop coverage and season. Overall, the results point to low importance of aboveground crop residues for soil arthropod communities and highlight that belowground plant resources, i.e. root exudates and root residues are the major driver of soil arthropod communities of arable systems. Thus, at least in short term removal of crop residues for e.g., biofuel production is likely to be of minor importance for soil arthropod communities. In contrast, changing crop species from wheat to maize markedly reduces the density of soil animals threatening the ecosystem functions they provide. [ABSTRACT FROM AUTHOR]