Structure of the nematofauna in Spanish Mediterranean continental soils

We studied the nematofauna in cultivated Euvisols in the Spanish Central Region in terms of multivariate statistical relationships between nematode groups and environmental variables (habitat, hosts, soil lexture, and quantitative edaphic variables). Three large nematode associations were recognized, one group being characteristic of the region's rotational crops (Pratylenchus, Ditylenchus, Helicotylenchus, Tylenchorhynchus, Rotylenchus, other Dorylaimidae,Plectus, andTylenchus), a second group related to cereal monoculture and wild gramineae associated with bush formations (Heterodera, Criconemoides, Discolaimus, and other Rhabditidae), and a third group characteristic of uncultivated soils (Paratylenchus, Xiphinema, Hemicycliophora, Mononchus, Tripyla, andAlaimus).Paratylenchus andTylenchus species were shown to have an indicator value for certain edaphic properties, especially soil texture, and may be regulated by the clay content of the soil.