摘要
植物根系对固定植株和获得水分和养分起重要作用,但是土壤不可观测性的限制,给根系生态学的研究带来一定的困难。因此,找到原位观察根系生长的方法对研究根系生态学就显得尤为重要。目前微根窗技术被认为是研究根系生态学最有前途的方法。从微根窗系统的组成、微根窗管的安装、微根窗图象的收集及微根窗数据的利用等几个方面进行了概述。阐述了在微根窗使用和操作过程中需要注意的几个问题,微根窗管与土壤之间的良好接触是获得高质量微根窗图像数据的前提和基础;图象收集的频率依赖于测定和计算的根系参数,如果想得到根系现存量、生产力、更新和寿命的信息,必须避免采样间隔时间过长。
Plant root plays an important role in anchorage and water and nutrient acquirement. However methodological limitations have troubled many researchers because of the inaccessibility of belowground systems. It appears important to find a good approach for in situ observation of root growth. The minirhizotron method has been regarded as the most promising method for root studies so far. This article aims to introduce the method to researchers in China and to synthesize several issues involved in the application of the minirhizotron method in terms of it＇s hardware, installation, digital image collection, data acquisition, and subsequent data analysis.
Minirhizotron tubes are main parts of the minirhizatron system. Minirhizotron tubes of different materials make different influence on growth and longevity of plant roots. Glass is the material carrying minimal influence at present. A key requirement for installation of minirhizotron tubes is to insure a good contact between the tube surface and the surrounding soil. Minirhizotron installation usually adopts a two-step tube installation method. But this method may not operate very well in several kinds of soils such as heavy textured soils, soils with abundant rocks and cobbles, soils with argillic （clayey） horizons, or loose structureless soils. The angles of minirhizotron installation are commonly 30°or 45°off the vertical.
Frequency of minirhizotron image collection has marked influence on the calculated veracity of the growth and death of roots during sampling intervals, for the growth and death of root occur frequently. The frequency of image collection depends upon the root demography and the time and resources available. If information about root standing crop, production, turnover and lifespan is desired, long sampling intervals should be avoided.
The basic information of birth, death, root number and root length can be derived from the minirhizotron image, which make it much easier to calculate root production and turnover （mortality）. Universally, it is based on the changes of color and morphology to identify living roots or dead roots. If the root changes from white to brown or black, or the root becomes shrivelling, softening, partial decomposed, or disappeared, it is viewed as dead root, but not all the roots that have changed from white to brown are dead roots. So it is still difficult to accurately discriminate the living roots and dead roots only through minirhizotron image.
出处
《生态学报》
CAS
CSCD
北大核心
2005年第11期3076-3081,共6页
Acta Ecologica Sinica
基金
中国科学院海外杰出人才团队资助项目~~
关键词
微根窗
根系生产
根系周转
根系死亡
minirhizotron
fine root
production
turnover
mortality
