Exploring the natural and human-induced effects on the assemblage of soil microarthropod communities in Argentina

In order to determine the independent and joint effects of: (1) crop management; (2) soil condition; and (3) site location on soil biota assemblage, we examined the effects of several crop management and soil condition descriptors on the abundance and diversity of soil microarthropods in crop fields. Data were analyzed using linear regression, canonical correspondence analysis and variance partitioning. Our results indicated that: (1) soil mites was the most affected group by crop management; (2) most of the variance on microarthropod abundance remained unexplained as none of the descriptors were able to explain more than 10% of total species matrix variance; (3) tillage intensity resulted in higher variance explained of the species matrix than pesticide use or crop rotation; (4) soil carbon was the most influential factor among soil condition descriptors; and (5) a significant component of species variation was accounted for by the spatially structured fraction of the explanatory descriptors and other underlying spatial processes. Following the methods proposed in this work, further studies based on the obtained results may increase their power to detect agriculturally induced effects on soil biota by including more soil fauna groups and more controlled environmental factors or by improving the description of the local scale spatial heterogeneity. (c) 2006 Elsevier Masson SAS. All rights reserved.