Abstract: In order to investigate the water use process of artificial planted Haloxylon ammodendron (C. A. Mey.) Bunge in Ulan Buh Desert, and reveal the ecological adaptability of artificial planted H. ammodendron, the sap flow of artificial planted H. ammodendron planted in 1979 and its environmental factors in Ulan Buh Desert were tested and observed by using PSTDP8 sap flow testing system and automatic meteorological station. The fluctuation law of sap flow and its relationship with total solar radiation, air temperature, relative humidity, wind speed, soil temperature and soil water content were studied by stepwise regression and correlation analysis. The results showed that the diurnal variation of sap flow in H. ammodendron stem was “single peak type” in sunny days and “double peak type” in rainy days. In summer, the sap flow started at about 7:00 in sunny days, peaked at about 9:30, and began to decline rapidly after 10:20, and basically dropped to a very low value at 21:30; there was still liquid flow appeared at night. The daily accumulation in H. ammodendron with diameter of 125 and 895 cm was 1423 and 260 L, respectively. In sunny days, the velocity of sap flow varied greatly, the flow velocity in the daytime was higher than that at night. The peak value of sap flow velocity in rainy days was significantly lower than that in sunny days, and the liquid flow at night in rainy days was less than that in sunny days. Correlation analysis showed that the environmental factors affecting the sap flow velocity of H. ammodendron were total solar radiation, soil moisture content, air temperature, air relative humidity, soil temperature and wind speed in sequence in sunny days, and the main environmental factors affecting the sap flow velocity of H. ammodendron were total solar radiation, air temperature, air relative humidity, soil temperature, wind speed and soil moisture content in sequence in rainy days. The present research provided theoretical support for the management of artificial H. ammodendron plantation, and had important theoretical and practical significance for management and protection of artificial H. ammodendron plantation in desert areas.

Key words: sap flow, Haloxylon ammodendron (C. A. Mey.) Bunge, Ulan Buh Desert, environmental factors

摘要： 为了揭示乌兰布和沙漠人工梭梭水分利用规律，探究人工梭梭的生态适应能力，利用PSTDP8树木茎流监测系统和自动气象站对乌兰布和沙漠1979年人工种植梭梭的液流变化及其周围的环境因子进行观测，采用逐步回归及相关分析法对茎干液流变化规律及其与太阳总辐射、空气温度、相对湿度、风速、土壤温度、土壤含水量的相关关系进行研究。结果表明：梭梭晴天茎干液流日变化呈“单峰型”，雨天茎干液流日变化呈“双峰型”；夏季晴天梭梭茎干液流在7:00左右启动，9:30左右出现峰值，液流在10:20以后开始迅速下降，至21:30基本下降到极低值，夜间仍有液流。直径125和895 cm的梭梭液流日累积量分别为1423 和260 L。晴天，茎干液流速率变化幅度较大，白天的液流速率高于夜间。雨天的液流峰值显著低于晴天，且夜间液流小于晴天。相关性分析表明，晴天，影响梭梭液流速率的环境因子依次为太阳总辐射、土壤含水量、空气温度、空气相对湿度、土壤温度、风速；雨天，影响梭梭液流速率的主要环境因子依次为太阳总辐射、空气温度、空气相对湿度、土壤温度、风速、土壤含水量。研究结果可为人工梭梭林的经营管理提供理论支撑，对沙漠地区人工梭梭的管理和保护有重要的理论和实际意义。

关键词: 茎干液流, 梭梭, 乌兰布和沙漠, 环境因子