青海大通几种主要灌木适宜土壤水分条件研究

研究不同土壤水分梯度下盆栽苗木四翅滨藜(Atriplex canescens)、中宁枸杞(Lycium barbarum)、沙棘(Hippophae rhamnoides)的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、水分利用效率(WUE)与土壤含水量(SWC)的关系.结果表明:维持沙棘、四翅滨藜和中宁枸杞净光合速率为最高的土壤含水量分别是18.88%,17.41%和18.49%,三树种维持叶片水分利用效率最佳土壤含水量依次为10.58%,15.3%,12%;土壤水合补偿点分别为4.3%,4.4%,4.54%,最大蒸腾速率的土壤含水量分别为21.25%,22.49%,21.64%,沙棘最适宜的土壤含水量应在10.5%左右,四翅滨藜应在10%～12%,中宁枸杞应在10%～15.5%.

Suitable soil water content of several kinds of shrub in project area of returning farmland to forests in Datong, Qinghai Province

In this paper, physiological parameters of Atriplex canescens, Lycium barbarum and Hippophae rhamnoides in different water condition in the field and under the condition of water menace were measured, and the relation among photosynthesis rate, stomatal conductance, transpiration rate, water use efficiency and soil water content was studied. The result shows optimum soil water content keeping max net photosynthesis rate of Atriplex canescens, Lycium barbarum and Hippophae rhamnoides were 18.88%, 17.41%, 18.49 %, Optimum soil water content keeping better leaf water use efficiency of the three shrub were 10.58 %, 15.3 %, 12 % respectively. Soil water compensation point for hydration of the three kinds of shrub were 4.3 %, 4.4%,4.54%. The suitable soil water content for transpiration rate of the three shrubs were 21.25%, 22.49% ,21.64% respectively. So as we know, the suitable soil water content of this three shrub Atriplex canescens were 10 % - 12 %, Lycium barbarum were 10 % - 15.5 %, Hippophae rhamnoides is about 10.5 %.