Spatial Distribution of Soil Nematode Communities in Stable and Active Sand Dunes of Horqin Sandy Land

Abstract

To explore the ecological significance of artificial plantation and the restoration process in sand dune ecosystems, the spatial distribution of soil nematode communities in stable and active sand dunes were investigated in northeastern Inner Mongolia, China. Soil nematode community structure and composition at five soil depths (0–5 cm, 5–10 cm, 10–20 cm, 20–40 cm, and 40–60 cm) and three slope positions (windward slope, top slope, and leeward slope) in the stable and active sand dunes were compared. The results showed that the total abundance of soil nematodes decreased with increasing soil depth in the stable sand dune, while increasing in the active sand dune. Bacterivores were found to be the most abundant group in both the stable and active dunes. Significant depth effects were found in the four nematode trophic groups. Thirty-eight and 29 genera were observed in the stable and active sand dunes, respectively. Acrobeles was dominant genus in the stable sand dune, while Acrobeloides was most prevalent in the active sand dune. The increasing values of generic diversity, evenness, and species richness, and the decreasing trend of the Simpson index from 0–5 cm to 20–40 cm were found in the stable sand dune. Nematode faunal analysis indicated that the soil food web in the stable sand dune was barely disturbed in comparison to the active sand dune. The positive interfeedback between soil and vegetation was the key to restoring the sandy ecosystems. Soil nematode communities can be used as bioindicators for assessing the rehabilitation of the sand dune ecosystems.