【作者】 郭宝妮；

【导师】 张建军；

【作者基本信息】 北京林业大学 ， 生态环境工程， 2013， 硕士

【摘要】 针对黄土高原干旱半干旱区植被重建过程中的植被耗水问题和水资源利用状况,为探讨黄土高原主要水土保持树种耗水特性及抗旱能力,本文采用TDP热扩散探针技术及计算大气蒸发力的半经验公式,分析了2009-2012年黄土高原大气蒸发力及主要水土保持树种刺槐(Robinia pseudoacacia)、油松(Pinus tabulaeformis)、山杨(Populus davidiana)和辽东栎(Quercus liaotungensis)树干液流速率的年、季、月及日变化规律,进一步分析了不同水土保持树种树干液流速率变化规律之间的异同及其分别与大气蒸发力变化规律的异同；分析了大气蒸发力和各水土保持树种树干液流速率的相关关系,得到不同树种不同季节树干液流速率和大气蒸发力的关系模型；计算了各水土保持林的年和季耗水量,并与林地的潜在蒸发力和降雨量对比分析,得出不同林地的差异及各季节缺水的严重程度。主要研究成果如下：1.在春末、夏季和初秋,落叶乔木树种刺槐、山杨、辽东栎树干液流速率日平均值动态变化规律及连日变化规律均与大气蒸发力相一致,常绿乔木树种油松连日变化规律均与大气蒸发力相一致,在春季、夏季和秋季,油松树干液流速率日平均值动态变化规律与大气蒸发力一致；各树种树干液流速率在不同季节表现出不同的大小关系,在初春和秋末,四个树种较为接近：春末、夏季和初秋,刺槐最大；冬季,油松最大。2.大气蒸发力及刺槐、山杨和辽东栎树干液流速率在春季、夏季和秋季的阴雨天呈明显下降趋势,在冬季,晴天和阴雨天差距不大；油松树干液流速率在四个季节均表现为晴天波动剧烈,日平均值较大,阴雨天气波动平缓,日平均值较小。3.在春末、夏季和初秋的典型晴天,刺槐、油松、山杨、辽东栎的树干液流速率均于7：00-10：00左右开始快速上升,于10：00-13：00左右到达峰值,在峰值持续较长时间(有时出现午休现象),于18：00-23：00左右降到谷底；在存在一定太阳辐射的阵雨天,刺槐、油松、山杨、辽东栎的树干液流速率目变化曲线开始上升时间和到达峰值时间均滞后于晴天1-2h左右,降到谷底的时间提前于晴天3-4h左右；在太阳辐射强度接近零的阴雨天气,四个树种树干液流速率连日变化不存在明显昼夜变化规律：在春末、夏季和初秋,四个树种夜间均存在一定的树干液流速率,在夜间树干液流持续稳定在显著低于白天的水平。在秋末、冬季和初春典型晴天,各树种树干液流速率日变化曲线表现为存在多个小波峰的不规则曲线,四个树种夜间均存在一定的树干液流速率,且树干液流稳定相对较高的水平。4.2009-2012年,四个树种树干液流速率月平均值年内分布基本一致,均于6月份到达峰值,在峰值处表现为：刺槐>山杨>油松>辽东栎,年内波动幅度顺序为刺槐>山杨>辽东栎>油松；大气蒸发力及四个树种树干液流速率季均值均表现为夏季最大冬季最小,春季和秋季均值较为接近。四个树种树干液流速率与大气蒸发力存在一定的相关关系,且两者在夏季表现为正相关,相关性最显著；在冬季表现为负相关,相关性最弱。5.2009-2012年,试验地四个季节的潜在蒸发量大小关系表现为：夏季>春季>秋季>冬季；四个季节降雨量大小关系表现为：夏季>春季>秋季>冬季；潜在蒸发量在四个季节均大于降雨量,夏季潜在蒸发量和降雨量差距最小,冬季次之,春季潜在蒸发量和降雨量差距最大,由此可知,春季是晋西黄土区缺水最为严重的季节。各水土保持树种的年蒸腾耗水最大小关系为：刺槐>汕松>辽东栎>山杨,其中刺槐和油松年耗水量较为接近,山杨和辽东栎年耗水量较为接近,刺槐和油松年耗水量明显大于山杨和辽东栎。更多还原

【Abstract】 Amiming at water consumption of trees construction and the using of water resources, for the purpose of investigating the ability of drought tolerance and water use efficiency of the trees planted in the Loess Plateau to adapt to arid environments, daily and seasonal changes of potential atmospheric evaporation in Loess Plateau and the sap flow velocity of4kinds of trees species for soil protecting in Semi-arid Area were studied by using the method of Thermal Dissipation Probe and semi-empirical formula from2009to2012. The water consumption of four stand in all seasons were estimated, and the correlation analysis between the Potential Atmospheric Evaporation and the sap flow velocity of4kinds of trees species were researched respectively, and based on which, the prediction model of the potential atmospheric evaporation and Sap flow velocity were created. The main results are as follows:1. The dynamic changes in the daily average of the sap flow velocity of Robinia pseudoacacia, Populus davidiana and Quercus liaotungensis are all the same as the dynamic changes of Potential Atmospheric Evaporation, and the diurnal variations of the sap flow velocity of them are also the same as one of Potential Atmospheric Evaporation, and the dynamic change of the sap flow velocity of Finus tabulaeformis is the same as one of Potential Atmospheric Evaporation in last spring, summer and early fall. However, the changes are different from the one of Potential Atmospheric Evaporation in other times. The dynamic change in the daily average of the sap flow velocity of Pinus tabulaeformis is all the same as the dynamic change of Potential Atmospheric Evaporation in spring, summer and fall, but winter. The sap flow velocity of Robinia pseudoacacia is the greatest among four trees in the last spring, summer and early fall, and the value, wave frequency and fluctuation range of the sap flow velocity of Pinus tabulaeformis are the greatest among four trees in winter.2. The values of the Potential Atmospheric Evaporation and the sap flow velocity of Robinia pseudoacacia, Populus davidiana and Quercus liaotungensis in sunny day are respectively higher than them in rainy day in spring, summer and fall, but winter. The value, the wave frequency and fluctuation range of the sap flow velocity of Pinus tabulaefonrmis in sunny day are the greater than them in rainy day in the whole year.3. In last spring, summer and early fall sunny days, the sap flow velocity of four trees increase rapidly from7:00to10:00, and reach a peak and stable on that value from10:00to13:00and sometimes midday depression phenomenon may be appeared, then it goes down, and stable on the bottom value from18:00to13:00. In last spring, summer and early fall shower days, the time when the sap flow velocity of four trees increase rapidly and reach peak all delay for1～2hours than sunny days. In last spring, summer and early fall days nearly without solar radiation, the diurnal variations of the sap flow velocity of four trees have no obvious day and night variations. There is a certain sap flow velocity in night and stable at a relatively low level for four trees in last spring, summer and early fall days. In last fall, winter and early spring sunny days, the diurnal variations of the sap flow velocity of four trees characterize by irregular curve and there is a certain sap (low velocity in night and stable at a relatively high level.4. The distribution of the monthly average value of the sap flow velocity of four trees during the year are basically the same from2009to2012, and all peak in June. The peak of the sap flow velocity of four trees from big to small was Robinia pseudoacacia, Populus davidiana, Pinus tahulaeformis and Ouercus liaotungensis, and fluctuating margin of the sap flow velocity of four trees from big to small was Robinia pseudoacacia, Populus davidiana,Quercus liaotungensis and Pinus tabulaeformis. The season average value of potential atmospheric evaporation and the sap flow velocity of four trees all show that:the mean value is the largest in summer, and least in winter, and the mean value in spring is more close to autumn, respectively. The most significant correlation between the sap flow velocity of four trees and the potential atmospheric evaporation have appeared in summer, and the worst in winter.and negative correlation between the sap flow velocity of four trees and the potential atmospheric evaporation have appeared in winter.5. The potential evaporation capacity are greater than precipitation in the whole year in the testing, respectively, and concludes that water shortage phenomenon exist all over years in the Loess Plateau. The gap between the potential evaporation capacity and the precipitation all show that:the largest in spring, and least in summer. And we can conclude that spring is the season when water shortage is most severe in the Loess Plateau.The transpiration water consumption of four trees is less than the potential evaporation capacity and the precipitation in the whole year in the testing. The transpiration water consumption of four trees from big to small was Robinia pseudoacacia, Firms tabulaeformis, Quercus liaotungensis and Populus davidiana, and the transpiration water consumption of Robinia pseudoacacia and Pinus tabulaeformis is obviously more than Quercus liaotungensis and Populus davidiana.更多还原