试论植物根系中水分运动的动力学  

ON FHE DYNAMICS OF WAFER MOVEMNET THROUGH ROOT SYSTEM

作　　者：邵明安[1] 

机构地区：[1]中国科学院水利部西北水土保持研究所

出　　处：《中国科学院水利部西北水土保持研究所集刊》1991年第1期38-51,共14页

摘　　要：根系中的水分运动是土壤—植物—大气连统体(SPAC)中水分运动的一个重要环节。根系的水分动力学性质随植物种而变,同一根随部位而变,并对环境因素敏感。根系除对通过它的水流呈现相当大的阻力外,还兼有水容特性。根系的水流阻力和水容均随植物的生长发育而变,木质部水流阻力随时间的变化表明:木质部中可能存在活的内含物。木质部的水流所遇到的阻力通常比径向流的小很多。然而,还没有充分的证据表明是否在水分迫胁的情况下木质部导管中气泡的形成会大大地增加其阻力。在三条径向流的可能通道中还不能确定那一条是主要的。Water movement through root system is a very important component of that in Soil-Plant-Atmosphere Continuum (SPAC).The water dynamic properties (absorptivity, permeability and conducfivity) of roots vary between species, and between different parts of the same roots (depending on age). They are sensitive to enviromental factors. The root system provides not only a considerable resistance to water flow through it, but also a hydraulic capacitance. The hydraulic resistance and capacitance in roots:vary with the growth and development of the plant. The change of xylem resistance to water flow with time indicates that there are some living contents in root xylem. Usually the xylem flow presents much less resistance than the radial flow in roots. However, there is no adequate evidence on whether the resistance may be greatly increased by bubble formation in vessels under water stress. It is uncertain which is the main pathway of radial flow in the three possible pathways.

关 键 词：根系水分动力学 径向流 轴向流 水流阻力 水容 

分 类 号：S157[农业科学—土壤学]