title: Soil fertility controls the size-specific distribution of eukaryotes.
abstract: The large range of body-mass values of soil organisms provides a tool to assess the organization of soil ecological communities. Relationships between log-transformed body mass M and log-transformed numerical abundance N of all eukaryotes occurring under organic pastures, mature grasslands, and seminatural heathlands in the Netherlands were investigated. The observed allometry of (M,N) assemblages of below-ground communities strongly reflects the availability of primary macronutrients and essential micronutrients. This log-linear model describes the continuous variation in the allometric slope of animals and fungi along an increasing soil fertility gradient. The aggregate contribution of small invertebrates (M < 1 microg) to the entire faunal community is highest under nutrient deficiency and causes shifts in the mass-abundance relationships. The phosphorus concentration in the soil explains 72% of these shifts but the nitrogen concentration explains only 36%, with copper and zinc as intermediate predictors (59% and 49%, respectively). Empirical evidence supports common responses of invertebrates to the rates of resource supply and, possibly, to the above-ground primary production of ecosystems.
authors.affiliation: National Institute for Public Health and the Environment, RIVM-LER, Bilthoven, the Netherlands. christian.mulder@rivm.nl
authors.forename: Christian
authors.initials: C
authors.lastname: Mulder
mesh_terms: D000818:Animals; D017753:Ecosystem; D056890:Eukaryota / Q000254:growth & development / Q000302:isolation & purification*; D006109:Poaceae / Q000737:chemistry; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology
chemical_list: D012987:Soil