荒漠绿洲农田防护树种二白杨生长季节树干液流的变化  

Sap flow of Gansu poplar in farmland shelter forest during the growing season in desert oasis

作　　者：常学向[1] 赵文智[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所

出　　处：《生态学报》2004年第7期1436-1441,共6页Acta Ecologica Sinica

基　　金：中国科学院知识创新资助项目 ( KZCX3 -SW-3 2 9;KZCX1-0 9) ;国家自然科学重点基金资助项目 ( 4 0 2 3 5 0 5 3 )~~

摘　　要：热脉冲技术已经成为确定林木耗水的有力工具。利用澳大利亚 GREENSPAN技术公司 SF- 30 0热脉冲树干液流仪 ,在生长季节对荒漠绿洲区农田防护树种二白杨树干液流速率进行了连续观测 ,结果表明 :二白杨树干液流速率的日变化规律为 ,夜间液流速率较低 ,其中最低值出现在 2 :0 0～ 3:0 0 ,7:0 0～ 8:30开始升高 ,1 3:0 0～ 1 4 :0 0达到最大值 ,1 6 :0 0～ 1 8:30开始下降 ;树干液流速率日平均值介于 1 0 .1± 4 .9g/ (cm2· h)～ 2 3.3± 8.2 g/ (cm2· h)之间。二白杨树干液流速率 8月份最高 ,7月份次之 ,5月与 9月份基本一致。树干液流与边材面积、叶面积指数呈显著线性相关 ,而与胸径、胸径平方与树高之积呈复合指数函数关系 。The Gansu Poplar (Populus gansuensis C.Wang et H. L.Yang ) shelter forest farmland play an important role in protecting and improving in the middle Heihe basin. It covers the area of about 18000 hectares and shelters farmland of 66700 hectares against damages of sandstorm and dry thermal wind. Understanding of water consumption in artificial Gansu Poplar forest is critical for assessing the balancing relation between the ecological function of artificial forest and the consumption of water resources. The heat pulse technique was considered as an effective method for measuring sap flow and transpiration of plant individual, and in turn, assessing water consumption. We used the heat pulse meter (SF-300, Greenspan technology Pty Ltd., Australian) to measure sap flow of Gansu Poplar individual. The objective is to specify the individual variability of sap flow and to determine water consumption by transpiration. The experimental site is located in the middle of Heihe basin, at Pinchuan town in Linze county, Gansu province (100°07′E, 39°21′N). According to different size of stem classes, 8 standard trees of Gansu Poplar were selected as sample plant, which were planted in 1983. Sap flow was measured by heat pulses lasting 1.6 seconds every 30 minutes from Apr. 20 to May.21 and from 11th to 21st in July, Aug., and Sept., 2003, respectively. Green leaf area of a sub-sample of leaves per tree was measured every 5 days from Apr. 23 to July15 using a leaf area meter (model LI-3000, Li-Cor Inc., Lincoln, NE). Total green leaf area was estimated by multiplying leaf area measured by the ratio between the fresh leave weight of the sub-sample and total-sample. During the growing season, the diurnal sap flow velocity of Gansu Poplar was lower at night, with lowest at 2:00～(3:00,) and started to rise rapidly during 7:00～8:30, and then descend during 16:00～18:30. The maximum of sap flow velocity appears during 13:00～14:00. The maximum of average velocity of the sap flow occurred in August, and the second was in

关 键 词：树干液流 叶面积指数 生长季节 二白杨 农田防护林 荒漠绿洲 

分 类 号：S792[农业科学—林木遗传育种]