Use of ciliate communities for monitoring ecological restoration of grain for the green in north-western China

A 1-year baseline survey was conducted in north-western China to evaluate the ecological restoration quality of grain for green (GFG) using soil ciliate communities. The aims of this study were focused on analyzing the changes of soil ciliate communities in four plots (A, GFG for 15 years; B, GFG for 13 years; C, layland; D, cultivated land) for GFG environmental assessment. Simultaneously we studied the effects of vegetation communities and physical-chemical variables with GFG changes on soil ciliates. A total of 114 species of ciliates were identified among the four sample sites, representing 9 classes, 14 orders, 22 families and 37 genera. The community patterns of the soil ciliates were significantly correlated with the individual abundance of aboveground plants, soil water content, and soil porosity. The contents of total nitrogen were the main factor affecting the soil ciliate community composition. The species number, individual abundance, and diversity index of the ciliates were each in the order A>B>C>D; that is, the community composition of ciliates was complicated with the implementation of the GFG. It was shown that the succession of ciliate community shifts toward promoting the complexity with the progress of GFG. These findings demonstrate that soil ciliate communities may be used as a useful indicator to evaluate the effects of the ecological restoration quality of GFG.