Artrópodos del suelo: Relaciones entre la composición faunística y la intensificación agropecuaria

(Palabras clave: macroartropodos edaficos, variables fisicas y quimicas del suelo, cultivos anuales, pastoreo intensivo) ABSTRACT. Soils arthropods: Relationships between faunal composition and agricultural intensification: This paper establishes and shows the relationships between the presence and density of different soil macroarthropods and some physical and chemical soil properties. Also, it shows and discus the differences between soil macroarthropods communities in sites under different uses (agriculture, livestock and naturalized grassland). The contents of organic matter and total nitrogen showed significant differences between treatments (uses). Results show that the intensity of land use affects the abundance of several groups and the community composition; the total density of organisms and their richness declined significantly in agricultural systems and both variables were higher in naturalized sites. The C/N ratio and the percentage of organic matter were the variables that best explained the distribution of macroarthropods in different uses. The canonical correlation analysis indicates that the composition and density of macroarthropods are determined by the availability of food (in a positive way) and by agricultural intensification (negatively). We postulate that a higher complexity of the herbaceous layer favors macroarthropods while a lower complexity and the soil compaction favor the surface-walkers groups. We propose a conceptual model that could be used to predict the behavior of macroarthropods assemblages under other soil conditions.