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

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