半干旱黄土丘陵区沙棘和柠条水分利用与适应性特征比较

对半干旱黄土丘陵区坡地多年人工沙棘(Hippophae rhanvnoides)与柠条(Caragana korshinskii)林的土壤水分状况、生产力月动态以及光合生理和水势日变化特征进行比较．结果表明，沙棘与柠条深层土壤均存在不同程度的旱化现象，沙棘林在季节性土壤水分补偿深度和对深层低土壤水分的利用能力方面要强于柠条林．沙棘林的年度生产力大于柠条林．沙棘能够随着土壤水分条件的改善，而提高水分利用效率；柠条具有高光合特别是高蒸腾的光合生理特征，叶片水分利用效率较沙棘低．沙棘与柠条均兼具有御旱性与耐旱性，但沙棘对干旱的适应方式更积极主动．

A comparative study on water use characteristics and eco-adaptability of Hippophae rhamnoides and Caragana korshinskii in semi-arid loess hilly-gully region

This study compared the seasonal dynamics of soil water content,biomass productivity,and leaf photosynthetic physiology and water potential between about ten years old Hippophae rhamnoides and Caragana korshinskii planted on the hilly slope land of semi-arid loess hilly-gully region.The results showed that there existed dry soil layer in the stands.The seasonal compensation depth of soil water in Hippophae rhamnoides stand was deeper and its water use capability was better than those of C.korshinskii.The yearly productivity of Hippophae rhamnoides was about 2.56 times of C.korshinski.Hippophae rhamnoides leaf had a increased water use efficiency under improved soil water condition.C.korshinskii had higher photosynthetic and transpiration rates,but its leaf WUE was smaller than Hippophae rhamnoides.These two forests all had drought resistance and tolerance characteristics,but Hippophae rhamnoides was more active than C.korshinskii adapting to drought.