Soil nematode abundance and functional group composition at a global scale
Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.
| Summary: | Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few
quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes
are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced
samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the
composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass
of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions
(38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide
insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards
representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling
under current and future climate scenarios. |
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