Abstract: The classifying and clustering are equally important in grassland classification,based on this the idea the Integrated Orderly Classification System of Grassland(IOCSG) has been set up and follow six principles,namely,the Framework for a grassland classification system,Comprehensiveness of a grassland classification system,Relative stability of parameters used in grassland classification,Comparability of parameter stability at a given level of classification,Definitive power of parameters in grassland classification and Universality of a grassland classification system.The IOCSG contains three main levels.'Class',categories with moisture and temperature as their index;'sub-class',categories characterized by their edaphic conditions and 'types',classified according to their vegetation conditions.The IOCSG also contains seven thermal ranks and six humidity grades.According to the IOCSG 42 classes of natural grasslands may be identified globally and 41 of them present in China.The authors also investigated the IOCSG practical values in dealing with determining the habitat adaptive of species,prediction of evolution direction of grassland succession due to global changes and turf species introduction.The paper further enforces the significant influences of the grassland classification research on the grassland sciences in their fundamentals and practice.

Key words: Grassland type, Classfication, Cluster

摘要： 本文阐明分类与聚类在草原分类中同等重要。据此建立的草原综合顺序分类系统(IOCSG)应遵循6项原则,即草原分类要素的完整性原则、草原分类体系内涵的综合性原则、草原分类指标的相对稳定性原则、草原分类同级指标的可比性原则、草原分类特征指标的确限性原则和草原分类体系普适的周延性原则。该分类系统含有类(以地带性水热特征为指标)、亚类(以土地特征为指标)和型(以植被特征为指标)3个基本级别;7个热量级和6个湿润度级。依据本分类系统全球天然草原分为42类,中国有41类。本分类系统在生物种适宜度计算、全球变化对草原类型演替方向的预测、草坪引种等方面进行了论证。该文阐明了草原类型学对草业科学的基础理论意义和实践意义。

关键词: 草原类型, 分类, 聚类