Biotic indices based on soil nematode communities for assessing soil quality in terrestrial ecosystems.

Nematode communities offer several advantages for assessing the quality of soils. Diversity and maturity indices as well as trophic structure defining parameters based on the composition of soil nematode communities have been used to detect various kinds of man-induced disturbances and monitor ecological recovery. In the present paper we examined the response of these indices in herbaceous Mediterranean ecosystems. Incipient soils, which were developed on the top of waste dumping sites were compared with agricultural soils under fallow. Grasslands and old-fields were considered as reference systems. Either diversity or maturity indices were shown to be very sensitive to changes in soil system caused by waste dumping. However, they were less useful for the categorisation of perturbation in agroecosystems. Trophic composition related parameters were more meaningful for this aim. Plant parasite index (PPI) may be a good generic indicator of recovery processes after perturbation in these annual herbaceous ecosystems.