Abstract: In this paper, an investigation on the soil nematode communities under the canopy of Tamarix spp. at different habitats including sand dune, riverside wetland and saline wetland was conducted in Linze town, Gansu Province. In the study 1 245 soil nematode individuals in 20 genera were captured. The results show that the total number of nematodes was significantly higher in the soil under the canopy of Tamarix spp. than that in the soil out of the canopy at all the habitats; the total number of nematodes under the canopy ofTamarix spp. was higher than that out of the canopy at all the habitats, and that under and out of the canopy was in an order of fixed dune > riverside wetland > saline wetland. The bacterivores of  cp-2 guild (Ba₂) were dominant in bacterivores over fixed dune, whereas the herbivores of cp-3 guild (H₃) were dominant in plant parasites and prevalent in the both wetland soils. There was a significant restriction of soil salinity to the Ba₂ guild, but a few effect on the H₃ guild. It was found that the analysis on soil nematode communities is a useful method for interpreting the soil ecological process under the canopy of Tamarix spp. in arid area.

Key words: soil nematode, Tamarix spp., canopy, wetland, sand dune, Linze County, Gansu Province