Effects of wetland utilization change on spatial distribution of soil nematodes in Heihe River Basin,Northwest China

The first account of the effects of wetland reclamation on soil nematode assemblages were provided, three sites in Heihe River Basin of Northwest China, that is grass wetland (GW), Tamarix chinensis wetland (TW) and crop wetland (CW) treatments, were compared. Results showed that the majority of soil nematodes were presented in the 0–20 cm soil layers in CW treatments, followed by in the 20–40 cm and 40–60 cm layers in GW treatments. Plant-feeding nametodes were the most abundant trophic groups in each treatment, where GW (91.0%) > TW (88.1%) > CW (53.5%). Generic richness (GR) was lower in the TW (16) than that in GW (23) and CW (25). The combination of enrichment index (EI) and structure index (SI) showed that the soil food web in GW was more structured, and those in TW was stressed, while the enrichment soil food web was presented in the CW treatment. Several ecological indices which reflected soil community structure, diversity, Shannon-Weaver diversity (H′), Evenness (J′), Richness (GR) and modified maturity index (MMI) were found to be effective for assessing the response of soil namatode communities to soil of saline wetland reclamation. Furthermore, saline wetland reclamation also exerted great influence on the soil physical and chemical properties (pH, Electric conductivity (EC), Total organic carbon (TOC), Total nitrogen (Total-N) and Nitrate Nitrogen (N-NO ₃ ^– )). These results indicated that the wetland reclamation had significantly effects on soil nematode community structure and soil properties in this study.