Empirical test of hydraulic lift in 21 plant species in the Horqin sandy land，Inner Mongolia

We examined the hydraulic lift function of 21 psammophytes and clarified the characteristics of this process in the Horqin sandy land，Inner Mongolia. We used self-made growth boxes，in which the soil was separated into upper and lower layers by Vaseline. The water supply to the upper soil was controlled during the examination period. We determined the hydraulic lift effects by measuring the variation of soil water content in the upper soil. Results showed that the hydraulic lift process occured mostly during 00：00 to 06：00 hours. The amounts of hydraulically lifted water were different among species. The increment of soil water content lifted per gram of roots during 24 hours varied between 4.86 and 325.62 g/g， the average is 72.90 g/g. Four species，Artemisia wudanica，A. gmelinii，Thermopsis lanceolata and Bassia dasyphylla had higher hydraulic lift capability among all examined species. No marked correlation was observed between the drought degree of the upper soil and accumulative total water lifted by hydraulic process. It is significant to make use of hydraulic lift capability of psammophytes to improve the water content of shallow soil for artifical vegetations on semiarid sandy lands.