【作者】 王晓江；

【导师】 贺康宁；

【作者基本信息】 北京林业大学 ， 生态环境工程， 2008， 博士

【摘要】 本研究围绕土壤—植物—大气连续体系统（SPAC）内水分运动的动态观测,对库布齐沙漠的主要造林灌木四翅滨藜（Atripldex canescens（Purgh.）Butt.）、小叶锦鸡儿（Caragana microphylla Lam）、杨柴（Hedysarum laeve Maxim）、柽柳（Tamarixchinensis Loar）、互叶醉鱼草（Buddleja alternifolia Maxim）和蒙古莸（Caryopterismongolica Bunge）等树种的蒸腾耗水特性、水势以及生理生态等方面进行了系统研究,以对干旱、半干旱地区林业生态工程树种选择提供依据。主要探讨以下问题:1.研究区气候特征分析。2.不同植物（6种）的光合速率、蒸腾速率对土壤水分的日响应过程与机制。3.不同土壤水分条件对6种植物的光响应曲线的影响。4.环境因子对6种植物的叶水势日进程曲线的影响。5.SPAC中的势能梯度变化。6.土壤水分胁迫对6种植物的游离脯氨酸、可溶性糖含量的影响分析。7.土壤水分胁迫对6种植物SOD和CAT含量进行分析。8.土壤水分胁迫对6种植物MDA含量进行分析。9.探讨各供试灌木树种的耐旱机理。10.应用多指标进行各供试灌木树种耐旱性综合评价。主要研究结果:1.生长季6树种的耗水量大小排列顺序为:互叶醉鱼草（141.88mm）>小叶锦鸡儿（134.48mm）>杨柴（129.75mm）>柽柳（113.83mm）>四翅滨藜（108.70mm）>蒙古莸（103.54mm）。2.通过对不同林木光响应和日过程以及光合速率与土壤水分的关系研究,我们分别获得四翅滨藜、蒙古莸、柽柳、小叶锦鸡儿、杨柴和互叶醉鱼草6树种的光饱和点分别为:1611.00、1479.33、1476.67、1430.00、1391.00和1287.33μmol·s-1·m^-2;土壤水合补偿点分别为3.89%、4.55%、4.3%、4.4%、4.54%和4.46%。3.从清晨水势季节变化看,杨柴在生长季中的水分恢复是最好的,四翅滨藜和小叶锦鸡儿则显示有水分亏缺,植物水分胁迫的发生程度和它们的水分恢复的程度有一定关联.4.叶水势的日变化是由植物蒸腾作用消耗水分的速率和根系的水分供应能力的差异造成的,气象因子会通过影响植物的蒸腾作用而影响植物水势的变化。5.水分在SPAC连续体的运移中,能量主要消耗在最末端“叶—气”这一环节上,其次为“土—根”界面,在植物体内部,能量主要消耗在“茎—叶”节点中。水势差基本上随着季节推进呈现先增加后减小的趋势,其中“叶—气”水势差6月份最大,8月份最小,土根水势差7月份最大,9月份最小。6.从7月份蒸腾速率日变化的测定结果看,四翅滨藜保持着正常的蒸腾作用,反映出它有着良好的水分状况,并不存在水分亏缺;小叶锦鸡儿和杨柴的日变化则显示水分供应不充足,其中杨柴的水分状况更差一些。7.不同土壤水分处理对各供试灌木树种蒸腾、光合日进程规律的影响作用不大。随着水分胁迫的加剧,树种的蒸腾速率呈先上升后下降的趋势,四翅滨藜的光合速率随着胁迫的发展逐渐提高;小叶锦鸡儿和柽柳在轻度胁迫时光合速率处于最高值,随着水分胁迫的发展,光合速率又降低;杨柴则随着水分胁迫的发展,光合作用一直处于下降趋势。经过干旱胁迫处理的苗木,光响应曲线降低,水分胁迫越严重,降低的程度也越大。8.四翅滨藜、小叶锦鸡儿、杨柴、互叶醉鱼草、柽柳、蒙古莸6种盆栽苗木的萎蔫系数分别为:0.578%、0.711%、0.687%、2.11%、1.09%和1.22%,苗木的土壤水分利用率都在90%以上,根据耗水指数排序,得出6种苗木耐旱性排序:四翅滨藜>小叶锦鸡儿>杨柴>蒙古莸>互叶醉鱼草>柽柳。9.基于叶水势与土壤含水量的关系判断苗木的耐旱机理:小叶锦鸡儿、杨柴和蒙古莸为高水势延迟脱水耐旱树种,四翅滨藜、互叶醉鱼草为亚高水势延迟脱水耐旱树种,柽柳为亚低水势忍耐脱水耐旱树种。10.多指标综合评价供试树种的耐旱性:用模糊数学隶属函数公式对6个树种的21个指标进行了综合排序,其中年蒸腾量、土壤水合补偿点、干旱胁迫天数、萎蔫系数、耗水指数和b值等指标采用反隶属函数法。综合评价结果表明:6个树种耐旱能力大小依次为杨柴>四翅宾藜>柽柳>蒙古莸>小叶锦鸡儿>互叶醉鱼草。更多还原

【Abstract】 In order to provide reliable proof for the selections of plants in the course of vegetation recovering,a series of studies on Water Consumption Characteristics,water potential and Photosynthetic Characteristics of Atriplex canescens,Caragana microphylla,Hedysarum laeve, Tamarix chinensis,Buddleja alternifolia and Caryopteris mongolica were done in Kubuqi desert.The focused aspects are as following:1.Analysis of the climate character of the research area2.Study on the diurnal courses and mechanism of net photosynthetic and transpiration rate of six plants in different soil water content.3.Study on the responses of Photosynthesis and Transpiration of six plants in different soil moisture to light.4.Study on the influence of environmental factors on the diurnal courses of leaf water potential of six plants;5.The changes of water potential grades in the system of Soil-Plant-Atmosphere Continuum6.Responses of free proline and soluble sugar of six plants to the water pressure7.Responses of superoxide dismutase and catalase of six plants to the water pressure8.Responses of malondialdehyde of six plants to the water pressure9.Study on drought resistance mechanism of the potted plants,10.A comprehensive evaluation of drought resistance of the potted plants.Major conclusions are as following:1.The order of water Consumption of six shrubs in annual growing stage is 113.831mm、134.48mm、129.75mm、108.7mm、103.54mm and 141.88mm;2.Through the study on the relationship between growing and photosynthesis characteristics under different soil water content and light intensity,the light saturation point is differently:1611.00, 1479.33,1476.67,1430.00,1391.00,1287.33μmol·s-1-m^-2,and the light compensate point differently is:4.3%,4.4%,4.54%,4.46%,4.55%,3.89%.3.According to the change of leaf water potential in early morning,water recovery of Hedysarum mongolicum Turcz is the best.And it shows that some water wane in Acriplex canescens（Purgh.）Butt and Caragana microphylla.There has relationship between the degree of water wane and water recover. 4.The change of leaf water potential is the result of the rate of transpiration and water supply of roots,and some meteorologic factors can effect leaf water potential through effect transpiration.5.Main energy is consumed in the link of leaf and atmosphere in the system of SPAC,and secondly in the link of soil and root.Energy is consumed in the link of stem and leaf similarly.The difference of water potential takes a trend of falling follow increasing.The highest difference of leaf water potential and atmosphere water potential is in June and the lowest is in August.The highest difference of soil water potential and root water potential is in July and the lowest is in September.6.The result of daily course of transpiration in July shows that Atriplex canescensButt has normal transpiration,which indicates that it has better water condition,and that water supply is not ample in Caragana microphylla and Hedysarum laeve,so the water supply of Hedysarum laeve is worse.7.Tt has little difference in the daily change of Transpriation and Photosynthesis of potted plants under different soil water content.Tr takes a trend of falling follow increasing with the development of drough.At the same time,Pn of Atriplex canescens increase continually,whereas Hedysarum laeve falls continually,and Caragana microphylla and Tamarix ramosissma take a trend of falling follow increasing.The light responses of potted plants lower continually with the development of water drough.8 The Soil water content is 0.578%of Atriplex canescens,0.711%of Caragana microphylla, 0.687%of Hedysarum laeve,2.11%of Caryopteris mongolicaoT,1.09%of Tamarix ramosissma Ledeb,1.22%of Caryopteris mongolica Bunge differently when potted plants withered.The efficiency of water using of potted plants are all above 90%.The capability of plants resisting drough is sized up according soil water depleted index as following:Acriplex canescens（Purgh.）Butt>Caragana microphylla > Hedysarum laeve > Caryopteris mongolica > Caryopteris mongolicaor > Tamarix ramosissma.9.The resisting drough Mechanism of potted plants based on the relatationship between leaf water potential and soil water content is summed up as Caragana microphylla,Hedysarum laeve and Caryopteris mongolica belong to the plant that have high water potential to delaying dehydration; Atriplex canescens and Caryopteris mongolica belong to the plant that have sub-high water potential to delaying dehydration;Tamarix ramosissma belongs to the plant that has sub-low water potential to resisting dehydration.10.12 indexes of six trees were contrasted and compared by the way of subordination function of vague mathematics.The transpiration rate.,the drought-resistant abilities of the six trees species were listed in descending order as following:Hedysarum laeve >Atripldex canescens >Tamarix chinensis>Caryopteris mongolica >Caragana microphylla >Buddleja alternifolia.更多还原