Soil nematode abundance and functional group composition at a global scale

Abstract

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, no 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 6,579 georeferenced samples to generate a mechanistic understanding of the patterns of global soil nematode abundance and functional group composition. The resulting maps show that 4.4 ± 0.64  10 20 nematodes (total biomass ~0.3 Gt) inhabit surface soils across the world, with higher abundances in sub-arctic regions (38% of total), than in temperate (24%), or tropical regions (21%). 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 into global biogeochemical models, to predict elemental cycling under current and future climate scenarios.

Establishment of a marine nematode model for animal functional genomics, environmental adaptation and developmental evolution

“…Nematodes represent about 80% of all the multicellular animals on Earth, and play major roles in many ecosystems (Eisenhauer and Guerra 2019;van den Hoogen et al 2019). They occupy essentially all ecological niches: hot springs, polar ice, soil, fresh and salt water, and as parasites of plants, animals and humans.…”

Agriculture erases climate constraints on soil nematode communities across large spatial scales

“…To meet increasing food demands, a large number of natural systems is being converted to agricultural ecosystems at a global scale (Tilman, Balzer, Hill, & Befort, 2011). Conversion of natural to agricultural ecosystems was shown to reduce the biodiversity of insects, plants, birds, and mammals at both local and regional scales, and to homogenize biological communities across space (Flynn et al, 2009;Gossner et al, 2016;Karp et al, 2012;Ponisio, M'Gonigle, & Kremen, 2016;Solar et al, 2015).…”

Natural diversity in the predatory behavior facilitates the establishment of a new robust model strain for nematode-trapping fungi

“…The living component of soils are in permanent interaction and play central roles in various aspects of biogeochemistry, including nutrient cycling and transport across distances (1). Specifically, nematodes are the most abundant animals in nature, amounting to a staggering 0.3 gigatonnes or 4.5 x 10 20 individuals, many of which are devastating parasites of plants, animals and humans (2). Although available, nematicide chemicals pose severe environmental and health risks and therefore, biological control agents such as carnivorous predatory fungi hold potential as alternative pest control tools.…”