Relation between Plant and Groundwater Depth: A Case Study in Subei Lake of Ordos Plateau

Based on the method of investigating natural vegetation and exposing groundwater table by sinking shallow wells with hand drill, the relations between total coverage of vegetation community, respective coverage of each species and species succession and groundwater depth are established in Subei Lake of Ordos plateau. The results indicate that there is significant correlation between total coverage of vegetation community and groundwater depth within 1.6m. The respective coverage of some wetland species has different peak values. It indicates that these species have certain ecological groundwater depth. The relation between species succession and groundwater depth shows that wet and saline vegetation are predominant when groundwater depth is less than 0.6m. xerophyte and sandy vegetation are predominant when groundwater depth is above 3.2m. In addition, 1.6m is the critical groundwater depth of vegetation ecotone. This region has the largest number of vegetation species.