六盘山半干旱区华北落叶松林的生长季蒸散量和组分特征  

The evapotranspiration and its partition in growing season for a stand of Larix principis-rupprechtii plantation in the semi-arid region of Liupan Mountains, NW China

作　　者：李振华[1] 王彦辉[1] 于澎涛[1] 童鸿强[2,1] 王艳兵[3,1] 刘千[4,1] 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所//国家林业局森林生态环境与保护重点实验室,北京100091 [2]江西省宜春市水务局,江西宜春336000 [3]内蒙古农业大学林学院,内蒙古呼和浩特010019 [4]甘肃农业大学资源与环境学院,甘肃兰州730070

出　　处：《生态环境学报》2013年第2期222-228,共7页Ecology and Environmental Sciences

基　　金：国家林业公益性行业科研专项(201104005-02;200904056);国家"十二五"科技支撑计划项目(2011BAD38B0503;2012BAD22B030102);国家自然科学基金项目(41230852;41071023);宁夏六盘山森林生态站资助

摘　　要：在宁夏六盘山半干旱区叠叠沟小流域,采用热扩散探针、微型蒸渗仪等在2009—2011年生长季(5—10月份)连续测定了华北落叶松(Larix principis-rupprechtii)人工林的林冠蒸腾、林冠截留及林地蒸散等林分蒸散组分的数量和比例及其月变化。结果表明,2009—2011年的生长季林分蒸散量分别为446、532、426 mm,其年际差别与水分条件、气温和林分叶面积指数有关。蒸散组分中,林冠蒸腾平均占总蒸散的35%、林冠截留占18%、林地蒸散占47%,即53%的蒸散由林冠层产生。林冠月蒸腾在水分充足时主要受饱和水汽压差和太阳辐射影响,在水分缺乏时与诸气象因子相关不显著;其占月蒸散的比例在生长季内持续下降,从5月份最高的51%降到10月份最低的22%。林冠截留的70%集中在雨季7—9月份,其数量与降水量相关紧密;占月蒸散的比例在5、6月份较低(平均11%),在7—10月份较高(21%)。林地蒸散量的季节变化呈单峰型,主要受降水量影响,在8月份最高;其各月占林分蒸散的比例呈持续上升趋势,从5月份最低的32%升到10月份的57%。文中半干旱区林分是典型的水分限制型生态系统,降水量是影响林分蒸散及其组分变化的首要因素。降水类型及其季节分配等其他因素的影响须在短时间尺度上进一步研究。The canopy transpiration （T）, canopy interception （/） and forest floor evapotranspiration （ETf） in a stand of Larix principis-rupprechtii plantation were continuously measured in the growing season （May-October） of 2009--2011, using the techniques including thermal diffusion probes and micro-lysimeters, in a semi-arid small watershed of Diediegou located at the Liupan Mountains of Ningxia Hui Autonomous Region, northwest China. Then, the total stand evapotranspiration （ET）, the relative contribution of each ET component and their monthly variation were analyzed. The results showed that the total ET in the growing season of 2009, 2010 and 2011 was 446, 532, 426 ram, respectively; this inter-annual difference was influenced firstly by the water condition, then by the air temperature and stand LAI. Within the stand ET, the T amounted to 35%, while the I and ET/amounted to 18% and 47%, respectively. This meant that 53% of the total stand ET was caused by the stand canopy. The monthly Twas mainly constrained by the vapor pressure difference （VPD） and solar radiation when soil water was abundant, but showing no significant relation with the meteorological factors under water deficit condition. The monthly ratio of T/ET decreased gradually in the growing season, from the maximum of 51% in May to the minimum of 22% in October. 70% of I concentrated in the rainy period （July-September）, the variation of monthly I was closely dependent on the monthly precipitation. The monthly ratio of I/ET was lower in May and June with an average of 11%; and higher in the period from July to October with an average of 21%. The monthly ETf in the growing season varied in a pattern of single peak which appeared in August. This was mainly determined by the variation of monthly precipitation. However, the monthly ratio of ET/ET presented an increasing tendency, from 32% in May to 57% in October. This stand with semi-arid climate studied in this paper is a typical water-limited ecosystem, and the precipitation amou

关 键 词：半干旱地区 森林蒸散 组分 蒸腾 截留 蒸发 

分 类 号：S718.51[农业科学—林学]