Physiological Response of Desert Vegetation under Different Groundwater Depths in Arid Areas

In this paper, through the determination of Haloxylon ammodendron and Tamarix’s physiological indices under different groundwater depths, we can analyze the effect on Haloxylon ammodendron and Tamarix’s physiological indexes under the drought stress, the result showed that: (1) In the test site 2, in June Haloxylon ammodendron’s Chlorophyll content is less than the Chlorophyll content of Haloxylon ammodendron in July and August, and the order of Tamarix’s Chlorophyll content is July > June > August, in June the light energy utilization of Haloxylon ammodendron and Tamarix is largest; (2) Proline content changes illustrates the degree of drought stress, the accumulation of proline content in Haloxylon ammodendron and Tamarix increases with drought stress becoming larger, and in the same depth of groundwater, the accumulation of proline in Tamarix is bigger than the accumulation of prolie in Haloxylon ammodendron; (3) The change of soluble sugar and malondialdehyde content reflects the degree of drought stress, the accumulation of soluble sugar and malondialdehyde content increases with drought stress becoming larger for Haloxylon ammodendron, but in the depth 6-7m of groundwater the accumulation of soluble sugar and malondialdehyde content for Tamarix is abnormal, the groundwater in the depth 6-8 m is the threshold for the accumulation of soluble sugar and malondialdehyde content for Tamarix.