灌溉对三种荒漠植物蒸腾耗水特性的影响  

Effects of different irrigation regimes on characteristics of transpiring waterconsumption of three desert species

作　　者：单立山[1] 李毅[1] 张希明[2] 王蕙[1] 

机构地区：[1]甘肃农业大学林学院,兰州730070 [2]中国科学院新疆生态与地理研究所,乌鲁木齐830011

出　　处：《生态学报》2012年第18期5692-5702,共11页Acta Ecologica Sinica

基　　金：国家国际科技合作专项(2012DFR30830);中国科学院知识创新工程重要方向性项目(KZCX3-SW-342-02);科技部农业科技成果转化资金项目(2009GB2G100375)

摘　　要：利用热平衡式茎流计和压力室对塔里木沙漠公路防护林不同灌溉量条件下3种荒漠植物多枝柽柳(Tamarix ramosissima)、梭梭(Haloxylon ammodendron)和乔木状沙拐枣(Calligonum arborescens)的液流变化、水势进行了测定。研究结果表明:(1)茎干液流速率因灌溉量和物种的不同而异,同一灌溉量条件下不同物种间表现为多枝柽柳>乔木状沙拐枣>梭梭,不同灌溉量条件下3种荒漠植物的茎干液流速率均随灌溉量的减少而显著降低。3种荒漠植物的夜间蒸腾占有一定比例,表现为梭梭(18.68%)>乔木状沙拐枣(17.48%)>多枝柽柳(12.82%),表明3种灌木均可通过夜间液流以补充植物体白天的水分消耗,表现出较强的抗旱性,但梭梭形成的叶片-冠-根的水势差相对较大,夜间补偿流较多,表现出更强的抗旱性。多枝柽柳和乔木状沙拐枣茎干液流日变化趋势基本相同,在灌溉量为35 kg·株-1.次-1和28 kg·株-1.次-1时均呈单峰曲线,液流速率较高且变化幅度较大,而灌溉量为17.5 kg·株-1.次-1时呈双峰曲线,液流速率较低;梭梭在不同灌溉量条件下其变化均呈单峰曲线,即当灌溉量降低到17.5 kg·株-1.次-1时多枝柽柳和乔木状沙拐枣可能出现了水分亏缺,通过调节气孔张开度或部分关闭降低蒸腾来适应其胁迫条件,但该灌溉条件下梭梭并没有出现水分亏缺,表明出较强的抗旱性。(2)相同时间不同灌溉量条件下,3种荒漠植物的清晨水势和午后水势均随着灌溉量的减少而降低;整个生长季相同时间同一灌溉量条件下,3种防护林植物的清晨、午后水势表现为乔木状沙拐枣>多枝柽柳>梭梭,表明3种荒漠植物在相同的灌溉条件下梭梭因保持较低的水势表现出较强的抗旱性。(3)相同时间不同灌溉量条件下,3种荒漠植物单株日耗水量均随着灌溉量的减少而减少,整个生长季各处理日平均耗水量的动态变化趋势均为单峰型,7月份耗水量�The sap flow velocity and leaf water potential of three desert shrubs （Tamarix ramosissima, Haloxylon ammodendron, and Calligonum arborescens） , grown under three different volumes of irrigation water in the Tarim Desert Highway shelterbelt, which is located at Taklimakan Desert of China, were measured using a heat-balance stem flow gauge and press chamber. The sap flow velocity differed among the species and among the irrigation volume treatments. Under the same irrigation volume, the sap flow velocity of the three species followed the rank order T. ramosissima 〉 C. arborescens 〉 H. ammodendron. The sap flow velocity of the same species decreased significantly with reduction in irrigation volume. Thenight-time transpiration of the three species as a proportion of total diurnal transpiration followed the order H. ammodendron （ 18.68% ） 〉 C. arborescens （ 17.48% ） 〉 T. ramosissima （ 12.82% ）. These results indicate that the water consumption of the three species during the day can be supplemented through the sap flow at night, which results in increased drought resistance. The water potential of leaf-canopy-root of H. ammodendron was higher, and the compensatory sap flow at night was higher, than that of the other species and thus conferred stronger drought resistance. The diurnal variations in sap flow velocity of T. ramosissima and C. arborescens were similar. In both species, the diurnal variation in sap flow velocity was represented by a single-peaked curve, the sap flow velocity values were higher and the extent of variation was wider under irrigation volumes of 35 and 28 kg· plant-1, time-1. With an irrigation volume of 17.5 kg· plant-1· time-1 the diurnal variation in sap flow velocity was represented by a two-peaked curve and the sap flow velocity values were lower than those of the other treatments. The diurnal variation in stem sap flow velocity of H. ammodendron showed a single-peaked curve under each of the irrigation volume treatments. These results indicate that water defic

关 键 词：塔里木沙漠公路 液流速率 水势 耗水量 

分 类 号：S718.4[农业科学—林学]