Impact of human activities on nematode communities in terrestrial ecosystems

Abstract

Soil nematodes use a small proportion of the primary production in ecosystems (0.06–4.3%), but their role in many processes is important. Phytophagous nematodes consume 1.4–21.8% of the primary production of roots, whereas bacteriophages consume, via bacteria and fungi, about 40% of the organic matter decomposed over a year. Examples are given of the effect of addition of mineral nitrogen fertilizers, of nitrogen mineralization after drainage of peatland, and of the effect of different types of landscape on functional groups of nematodes. The proportion of plant parasites and bacteriophages increased after perturbation whereas the proportion of pantophages and predators decreased, the species richness declined, and individual body weight was reduced. All these observations provide evidence of functional changes.