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塔克拉玛干沙漠地下水储量丰富,但因埋深和水质的限制,植物可有效利用的水资源十分有限。通过分析沙漠特有灌木塔克拉玛干沙拐枣(Calligonum taklimakanensis B.R.Pan & G.M.Shen)气体交换特性对地下水埋深和水质变化的响应,探讨了地下水对天然植物分布及生长的影响。结果显示,有天然植被分布的区域地下水埋深一般较浅,土壤水分供应充足;但受地下水矿化度、总硬度、总碱度、全盐含量及各离子含量比例的区域间差异影响,不同区域的塔克拉玛干沙拐枣气体交换特性各不相同。地下水总碱度大小是影响塔克拉玛干沙拐枣光合特性最主要的因素,总碱度增加时,净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)及潜在最大净光合速率(Pmax)、光补偿点(LCP)和光饱和点(LSP)分别从14.9±0.39μmolCO2·m-2·s-1、6.79±0.21mmol·m-2·s-1、0.192±0.013mmol·m-2·s-1、21.4±1.1μmolCO2·m-2·s-1、175.5±3.5μmol·m-2·s-1、1805±31.2μmol·m-2·s-1降为11.7±0.5μmolCO2·m-2·s-1、5.79±0.18mmol·m-2·s-1、0.130±0.009mmol·m-2·s-1、16.3±2.5μmolCO2·m-2·s-1、78.1±15.8μmol·m-2·s-1、1564±55.6μmol·m-2·s-1。研究结果还表明,较浅的地下水埋深是沙漠腹地天然生植物生存繁衍的必要条件,塔克拉玛干沙拐枣天然分布区的适宜地下水埋深应在1.5～2.5m的范围内;塔克拉玛干沙拐枣也具有很强的盐碱耐受能力,在矿化度高达16g·L-1的环境中依然能正常存活生长。
The Taklimakan Desert has abundant groundwater reserves, but due to the depth and water quality limitations, the available water resources of plants are very limited. The effects of groundwater on the distribution and growth of natural plants were discussed by analyzing the response of gas exchange characteristics of Calligonum taklimakanensis B.R. Pan & G.M.Shen to changes in groundwater depth and water quality. The results showed that the depth of groundwater in areas with natural vegetation was generally shallow and the supply of soil water was adequate. However, the differences were affected by the regional differences in salinity, total hardness, total alkalinity, total salt content and ion content of groundwater Regional Taklimakanza jujuba gas exchange characteristics vary. The total alkalinity of groundwater is the most important factor that affects the photosynthetic characteristics of Taklimakanma jujube. The net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and the maximum potential net photosynthetic rate Pmax, LCP and LSP increased from 14.9 ± 0.39μmolCO2 · m-2 · s-1, 1.69 ± 0.21mmol · m-2 · s-1 and 0.192 ± 0.013mmol · m- 2 · s-1,21.4 ± 1.1μmolCO2 · m-2 · s-1,175.5 ± 3.5μmol · m-2 · s-1,1805 ± 31.2μmol · m-2 · s-1 to 11.7 ± 0.5μmolCO2 · M -2 · s -1.5.79 ± 0.18 mmol · m -2 · s -1 · 0.130 ± 0.009 mmol · m -2 · s -1,16.3 ± 2.5μmolCO 2 · m -2 · s -1 1,78.1 ± 15.8 μmol · m-2 · s-1, 1564 ± 55.6 μmol · m-2 · s-1. The results also show that the shallow depth of groundwater is a necessary condition for the survival and reproduction of native plants in the desert hinterland. The appropriate groundwater depth in the natural distribution area of Taklimakan sagittatus should be in the range of 1.5-2.5 m. Has a strong saline tolerance, in the salinity of up to 16g · L-1 environment still normal survival and growth.