respectively (FF = fungal feeders), Tylenchidae feed especially on root-hairs (RHF = root-hair feeders), the other genera are strict plant-parasites (PF = plan-feeders).

Helicotylenchus spp., Paratylenchus spp., Pratylenchus spp., Rotylenchus spp., and Tylenchidae were the most dominant taxa as they were recorded in more than 70% of the samples with the highest mean abundances.

Tylenchidae, Helicotylenchus spp., Rotylenchus spp.

While with the other PPN genera, Helicotylenchus spp., Tylenchidae, Ditylenchus spp., Criconema spp., Gracilacus spp.

Aphelenchoides spp., Gracilacus spp., Pratylenchus spp., Rotylenchidae and Tylenchidae were supported by coarse textures as it was previously observed in the Souss region (Ferji and Geraert, 1997).

We should note that the plant-associated family of Tylenchidae, which are usually classified as algal and root-hair feeders, might also have fungal feeding habits (Yeates et al.

Tylenchidae were included in the estimation of PPI, as in most studies of soil nematodes.

The most abundant trophic group was the bacterivores, accounting for almost 50% of the overall community, followed by fungivores and Tylenchidae. The abundance of bacterivores did not differ among microsites, whereas that of fungivores was significantly lower in bare soil.

If we consider the possible fungal feeding habits of Tylenchidae, which accounted for >20% of our community and have not been considered in the calculation of CI, the fungal component of our soil food web becomes even more important.