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题名	塔克拉玛干沙漠腹地三种植物根系构型研究
作者	杨小林
学位类别	硕士
答辩日期	2008
授予单位	中国科学院．新疆生态与地理研究所
导师	张希明，新疆生态与地理研究所
关键词	塔克拉玛干沙漠
其他题名	Analysis of root architectural and root adaptive strategy in the hinterland of Taklimakan desert
中文摘要	在塔克拉玛干沙漠腹地，采用挖掘法挖取塔克拉玛干柽柳（Tamarix taklamakanensis）、塔克拉玛干沙拐枣（Calligonum roborovskii）和罗布麻（Apocynum venetum）根系，运用拓扑结构理论以及分形理论对其根系构型特征进行研究。研究发现：1、三种植物根系均以水平分布占优势，根系浅层化。2、三种植物具有不同的根系结构适应性，根系表现为两种不同的根系分支模式，塔克拉玛干柽柳根系为叉状分支结构（ =0.15、 =0.09、TI=0.658），罗布麻（ =0.43、 =0.35、TI=0. 83）、塔干沙拐枣（ =0.52、 =0.38、TI=0.86）根系趋向于鱼尾型分支结构。3、三种植物根系的连接长度都较大，最小也达1.12m，说明在沙漠腹地，三种植物通过增加根系连接长度来扩大根系在土层中的分布范围，从而提高根系的有效营养空间，增加根系的连接长度也是根系对沙漠腹地资源贫瘠的土壤环境的一种良好适应。4、研究验证了Leonardo da Vinci法则，三种植物根系分支前的横截面积等于根系分支后的横截面积之和，符合Leonardo da Vinci法则。5、在塔克拉玛干沙漠腹地，塔克拉玛干柽柳、塔干沙拐枣根系的分形维数具有明显的差异性，表明了两种植物根系分支模式的不同。6、根系具有典型的分形结构，根系分支前后横截面积比 、根系生物量分配比 与根系的直径之间不存在相关关系，所以说根系分支前后横截面积相似以及根系生物量分配比是植物根系构型的一般性特征。7、由于根系分支点的直径与根长、生物量之间存在较好的相关关系，而且根系具有显著的自相似性，因此可以根据根系分支点直径对根系生物量、根长进行预测估计。研究表明沙漠腹地三种植物根系构型特征具有相似性和差异性，在相似的沙漠环境中具有不同的根系适应策略。Fractal geometry is a potential new approach to the analysis of root architecture, which may offer improved ways to quantify and summarize root system complexity as well as yield ecological and physiological insights into the functional relevance of specific architectural patterns. Otherwise, fractal analysis is a sensitive measure of root branching intensity and fractal dimension expresses the ‘space filling’ properties of a structure. The objective of this study was to find out the fractal characteristics of root system in the hinterland of Taklimakan desert. The whole root system of two naturally species was excavated and exposed with shovels in 2007.These species includes: Tamarix taklamakanensis, Calligonum roborovskii. A one-factorial ANOVA with species as factor showed a highly significant effect on fractal dimension, the difference of fractal dimension indicates the otherness of root branching pattern. The regression between link diameter and ,q were not significant for either species .So the ratio of the sum of root cross-sectional areas after a bifurcation to the cross-sectional area before bifurcation, and the distribution of the cross-sectional areas after bifurcation, q are the ubiquitous characters of root system. In this paper, we find the significant linear relationships between the diameter after branching and root length, biomass respectively, because root branching is self-similar and branching rules are the same for roots of all sizes, root lengths，root biomass for the root systems of whole trees can then be estimated by measuring the diameter of each root at the base of the trunk or diameter after branching. The study showed that diameter of each root at the base of the trunk or diameter after branching are effective indexes which can measured easily to estimate the root lengths, biomass and other parameter of root architecture. Root architectural properties can be divided into geometric properties and topological properties. Topological properties are believed to influence the efficiency and costs of resource exploitation in terms of carbon required for root segment construction. Aspects of root architecture, including topology, link length, diameters and scaling relations, were analyzed in excavated coarse root systems of three natural species in the hinterland of taklimakan desert. The natural species include Tamarix taklamakanensis,Calligonum roborovskii and Apocynum venetum. The result indicated that root distribution was absolutely dominated by horizontal roots. The branching pattern of root system were different: the shrub T.taklamakanensis tend to be dichotomous ( =0.15, =0.09,TI=0.658)and Calligonum roborovskii ( =0.52, =0.38,TI=0.86 ) Apocynum venetum( =0.43, =0.35,TI=0. 83 )were herringbone-like. The lengths of links are very long for all the species in the desert, the shortest one still is 1.12m. The result showed that the different architectural strategies can be explained in terms of cost–benefit relations and efficiency in soil resource exploration and exploitation. We can include the difference and similarity of root architectural with different species which indicated the difference and similarity of strategy in exploitation and exploration. We also tested the pipe-stem theory, essentially dating back to Leonardo da Vinci, which underlies many models and which we found conformed to our measurement data with reasonable accuracy.
语种	中文
学科主题	植物生态学
公开日期	2010-11-12
页码	共63页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8056]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	杨小林. 塔克拉玛干沙漠腹地三种植物根系构型研究[D]. 中国科学院．新疆生态与地理研究所. 2008.

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