Soil predatory mite communities (Acari: Gamasina) in agroecosystems of central Argentina

BEDANO, J.C.; RUF, A.

APPLIED SOIL ECOLOGY

ELSEVIER SCIENCE BV

Año: 2007 vol. 36 p. 22 - 31

0929-1393

The objective of this study was to compare soil predatory mite communities over a gradientof land use intensity in agroecosystems of Central Argentina. The study was conducted at LaColacha basin, Co´ rdoba, Argentina on coarse-loamy, illitic, thermic Typic Hapludoll. Foursites with different management systems (natural grassland, cattle raising, arable andmixed), but with the same Soil Series, similar geomorphological characteristics and thesame land use history until 50 years before, were sampled at four sampling dates. Thirtyeightspecies, 19 genera and nine families were identified. Ninety-two percent of theidentified species are new to science. This shows that the taxonomic knowledge of Gamasinais poorly developed in Argentina. In this study, Gamasina community structure wasclearly influenced by the management type. This confirms our hypothesis that Gamasinacommunity structure significantly changes as material and energy inputs and mechanicalperturbations in the system increased from the natural soil to the conventional agriculturalsites. The effects of agricultural practices could be observed in the occurrence of the species,the diversity and the dominance structure of the community, the maturity index, and also inseven similarity measures and the multivariate canonical correspondence analysis (CCA).Species number and diversity measures were highest in the cattle raising plot and very lowin the natural and arable site. So, in terms of species number, the arable field did not have animpoverished community in comparison with the natural undisturbed grassland.