不同灌溉量对绿洲-荒漠过渡带多枝柽柳幼苗根系生长和分布的影响  

Effects of Irrigation on Root Growth and Distribution of the Seedling of Tamarix ramosissimain Oasis-desert Ecotone

作　　者：王会提 曾凡江[1,2,3] 张波[1,2,3] 刘波 李尝君[1,2,3,5] 高欢欢[1,2,3,4] 郭自春[1,2,3,4] 

机构地区：[1]中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,乌鲁木齐830011 [2]新疆策勒荒漠草地生态系统国家野外科学观测试验研究站,新疆策勒848300 [3]中国科学院干旱区生物地理与生物资源重点实验室,乌鲁木齐830011 [4]中国科学院大学,北京100049 [5]新疆大学研究生院,乌鲁木齐830046

出　　处：《西北植物学报》2013年第12期2521-2528,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-EW-316);国家基金委-新疆联合基金重点项目(U1203201);国家自然科学基金项目(31070477;30870471)

摘　　要：为了探讨绿洲-荒漠过渡带上受损柽柳群落幼苗适宜生长的土壤水分条件，在塔南策勒绿洲外围设置A（不灌溉）、B（适度灌溉）、C（充分灌溉）3个处理的田间试验。于7～10月份考察了各处理柽柳幼苗粗根（〉2mm）和细根（〈2mm）生物量积累、空间分布等变化特征。结果显示：（1）随着灌溉量的增加，柽柳根系生物量积累不断增加，且在生长季末（10月份）增速最大，同时细根占总根重的比例从20.5％上升到29．8％，显著提高了幼苗吸收养分和水分的能力。（2）干旱胁迫（处理A）下柽柳幼苗根系的下扎深度大，但水平根幅的扩展却有限；适度灌溉（处理B）的生物量较处理A大，但小于处理C；根系扎根深度表现为处理A〉处理B〉处理C，各指标均处于中间状态；水分条件最好（处理c）时虽然垂直扎根深度小，但水平根幅最大，可以更有效利用浅层土壤资源。（3）柽柳幼苗大量根系集中在0～40cm的土壤表层，而且水分条件越好，这种集中趋势越明显；根系生物量随土壤深度的增加呈递减变化，细根的根长密度也有相似变化，但细根的比根长变化规律不明显，这可能与各层土壤微观环境的变化有关。研究表明，灌溉对柽柳幼苗根系的生长和分布有显著影响，充分灌溉下柽柳幼苗根系生物量积累最多且空间分布最大，该灌溉量有利于柽柳幼苗根系的正常生长和合理分布。Tamarix ramosissima community is facing a serious degradation at southern fringe of the Taklimakan Desert. Deficient water conditions impose restrictions on seedlings establishment and survival of T. ramosissima. In order to study root biomass accumulation and spatial distribution of T. ramosissima seedlings to provide suggestions for rehabilitating degraded ecosystem, we set up three irrigation treatments. treatment A （no irrigation）,treatment B （moderate irrigation） and treatment C （sufficient irrigation） at southern fringe of the Taklimakan Desert. Result showed that. （1）Irrigation significantly affected root growth and spatial distribution. The root biomass accumulation increased gradually with increased irrigation and the biggest growth rate at the end of growth season （October）. Meanwhile the proportion of fine roots also increased from 20.5% to 29.8% ,which improved the ability of absorbing moisture and nutrient from soil significantly. （2）Under drought stress （treatment A）, the root length of seedlings was the longest,while the horizontal distribution of root was restricted. Under moderate irrigation （treatment B）, the root biomass was more than that of treatment A but less than that of treatment C;the root level distribution of T. ramosissima seedlings.treatment A（treatment B（treatment C. While under the best water condition of the three treatments （treatment C）, the T. ramosissima root depth was shallow,but level distributing of root was most expander in order to use the shallow soil resources more effectively. （3）The most roots are distributed between 0-40 cm of the soil and the wetter, the centralized trend is more obvious. Root biomass was decreasing with the increase of soil depth, so had the same change of root length density of fine roots, but the change of specific root length of fine roots was unconspicuous which could be related with microcosmic environment of soil. The results showed that irrigation had a significant impact on root growth and distrib

关 键 词：多枝柽柳 根系生长 根系分布 灌溉 绿洲-荒漠过渡带 

分 类 号：Q944.3[生物学—植物学]