Abstract:

Plant adaptability refers to the characteristics optimization and survival ability nourishment of plants on multiple spatial-temporal scales through the processes of water and nutrient elements acquisition， regulation， growth and function maintenance. The sandy land plants in northern China have the characteristics of cold， drought and salt tolerance， wind and sand process resistance， and photophily， which are major basis for species selection， density allocation and management of biological control of desertification， and the theoretical basis for vegetation restoration and land degradation control in sandy land. However， studies on the relationship between sediment， plant water consumption， groundwater depth change and plant community on sandy dune land need to be further strengthened. The results show that the sediment depth of the Horqin Sandy Land gradually increases along the rivers west-eastwards from the mountain to the plain， and the depth of the sandy land in the middle part of the Horqin Sandy Land is the largest， about 200 m. There were significant differences in plant community characteristics among different types of dunes， and the changes in plant composition of mobile dunes were the most obvious. With the increase of land use pressure， groundwater depth increased， which affected the distribution pattern and composition characteristics of plants in Horqin sandy land. Dune fluctuation affects the relationship between plants and groundwater depth change.Water consumption of main plants in sandy land is between 300 mm and 450 mm， which is close to the average annual precipitation. Based on the water consumption of plants and the results of field investigation， the reasonable afforestation density in Horqin Sandy Land was between 225-375 plants per hectare. The restoration rate of desertified land in Horqin Sandy Land has entered a bottleneck period. After 1987， the effect of desertification control was not obvious. This study can provide scientific reference for the protection， control and utilization of desertified land in Horqin Sandy Land and the regions alike.

Key words: plant adaptability, sustainable restoration, stable vegetation, synergic relationship, Horqin Sandy Land