Abstract: This paper chose 3 typical afforestation species(Caragana korshinskii Kom.,Hippophae rhamnoides Linn., Pinus tabuliformis) in the soft sandstone area of Ordos, Inner Mongolia as study objects and compared their transpiration rates by SF60 stem flow meter. The results showed that: ①The transpiration rate of these 3 tree species showed a obvious changing rule in daytime and nighttime. The daytime transpiration rate was much higher than the nighttime when there was a weak and stable stem flow indicating a remarkable law with single and double peaks. ②The flow rate curve of the 3 tree species in the sunny days was relatively gentle and the peak range was wider. The flow started earlier and stopped later; in the rainy days, the peak value was steeper with narrow range, and the flow started later, stopped earlier; in the cloudy days, the flow rate curve was in the middle of the sunny days and rainy days. ③The transpiration rate of the 3 tree species was significantly correlated with the soil water content, and the correlation coefficients were all over 0.985. These results aimed at providing theoretical basis for forest planting management and rational utilization of water resources in arid areas.

Key words: soft sandstone area, Caragana korshinskii Kom., Hippophae rhamnoides Linn., Pinus tabuliformis, transpiration rate, soil water content

摘要： 以内蒙古自治区鄂尔多斯市准格尔旗砒砂岩区三种典型造林树种为研究对象，采用SF60茎流计对沙棘（Hippophae rhamnoides Linn.）、柠条锦鸡儿（Caragana korshinskii Kom.）和油松（Pinus tabuliformis）的蒸腾速率进行比较研究。结果表明：①三种树种均出现了明显的昼夜变化规律，白天的蒸腾速率远高于夜间，夜晚有微弱的稳定的树干液流存在，单、双峰规律明显。②在典型天气中，晴天三种树种树干液流速率曲线变化较平缓且峰值范围较宽，液流启动较早，停止较晚；在雨天，峰值较陡且范围较窄，液流启动较晚，停止较早；阴天居中。③三种树种的蒸腾速率与土壤含水率均呈显著相关，相关系数均在0.985以上。研究结果旨在为干旱区人工林的栽植管理及水资源合理利用提供理论依据。

关键词: 砒砂岩区, 柠条锦鸡儿, 沙棘, 油松, 蒸腾速率, 土壤含水率