Distribution of soil nematode communities along a section of Shen-Ha Highway

The effect of lead on soil nematode communities at the 0–20 cm depth was investigated along an increasing distance from a highway in Northeast China. The results showed that the abundance of total nematodes significantly increased from 40 m and then decreased eventually and the similar trend was also found in most indices studied. Thirty seven genera of nematodes belonging to 8 orders and 24 families were observed in our study, and Helicotylenchus was eudominant genus at all the sampling sites. The numbers of total nematodes significantly correlated with total and available Pb (P < 0.05), while ΣMI had a significantly negative correlation with TOC, Total N (P < 0.01) and C/N ratio (P < 0.05). Total and available Pb in soil had positive correlation with the numbers of total nematodes and bacterivores. The concentration of Pb also had an effect on abundance of Helicotylenchus, which increased in moderate concentration of Pb. NCR could be effectively used as indicators, as it was sensitive to concentration of Pb.