不同土壤水分含量对4个树种WUE的影响

Water Use Efficiency of Four Species under the Different Soil Water Content

在盆栽条件下对杨树、刺槐、沙棘、油松进行了3种土壤水分处理。研究结果表明:(1)土壤干旱严重影响树种的光合速率,各树种光合速率均为70%θf>55%θf>40%θf,在不同水分下各树种单叶WUE表现不一,杨树和刺槐在70%θf最高,沙棘则是55%θf下最高,在严重干旱下各树种单叶WUE均为最低。(2)4个树种在不同土壤水分及不同的月份其WUE大小不同,并且最大值出现的时间也不相同。在同一土壤水分下,杨树和刺槐各月的WUE显著高于沙棘和油松,油松各月的WUE最低。(3)各树种在3种土壤水分下总耗水量、总生物量均为适宜水分下最高,严重干旱下最低;在相同土壤水分下,4个树种的总耗水量、总生物量均为杨树>刺槐>沙棘>油松,4个树种总WUE均为中度水分亏缺下最高,严重干旱下最低。

Some indexes of the four tree species were studied under 3 soil water content. The result showed: (1) Soil water content remarkably influenced photosynthesis rate (Pn), and the four species Pn were all 75%θ_f>55%θ_f>40%θ_f; water use efficiency (WUE) of the four species was different: popular and locust were all showed 70%θ_f>55%θ_f>40%θ_f, yet seabuckthron did 55%θ_f>70%θ_f>40%θ_f. (2) Under the different soil water content and in the different months, the four species WUE was different, so did the appearance time of maximum. Under same soil water content, monthly WUE of popular and locust was higher than seabuckthron and Chinese pine remarkably, and the one of Chinese pine was the lowest.(3)The four tree species` total consuming water and total biomass were all 70%θ_f>55%θ_f>40%θ_f under the same soil water conditions. The two indexes of the four species were all popular > locust >seabuckthron>Chinese pine, yet total consuming water were all 55%θ_f>70%θ_f>40%θ_f.