基于草原综合顺序分类法的中国山地草地亚类分类研究

Definition of Comprehensive Sequential Classification System subclasses in Chinese montane grassland

草地作为陆地生态系统的重要组成部分,精准界定草地类型对草地资源研究具有重要意义。本研究基于数字高程模型(DEM),采用草原综合顺序分类法(CSCS),对中国山地草地亚类进行定量划分,并分析了草地亚类在山地区域的空间分布特征。结果表明:1)山地亚类共划分为20种,以小起伏山地亚类为主,面积分布最广泛;丘陵、中起伏山地亚类面积分布相当;大起伏和极大起伏山地亚类面积分布较少;2)原则上每种草地类型可划分为20种草地亚类,由于山地水热条件的空间差异,在特定环境下某些草地亚类并不存在;3)寒冷潮湿多雨冻原、高山草甸类(ⅠF36)的山地亚类面积分布最大;寒温潮湿寒温性针叶林类(ⅡF37)的山地亚类面积占第二位;暖热潮湿落叶-常绿阔叶林类(ⅤF40)的山地亚类面积居第三;亚热极干亚热带荒漠类(ⅥA6)的山地亚类面积分布最小。该研究结果可为草原开发利用、培育保护和经营管理,以及畜牧业的发展提供一定科学依据。

The Comprehensive and Sequential Classification System(CSCS)classifies vegetation types based on a two-dimensional coordinate map of seven thermal zones(Ⅰ-Ⅶ)and six humidity zones(A-F)to give 42 classes(Ⅰ A-Ⅶ F)and was originally developed in China for classification of diverse grasslands based on environmental factors.Grassland is an important part of the terrestrial ecosystem.The precise definition of grassland types is of great significance to the study of grassland resources.This study focused on montane grasslands in China and used the Digital Elevation Model(DEM) to quantitatively assess the areas of montane subclasses in China,identify grassland subclasses and analyze the spatial distribution characteristics of the subclasses.It was found that:1)Based on criteria of relief and altitude,20 montane subclasses were identified.The subclasses with the most extensive distribution area were mainly those of low relief.The distribution area of hilly and intermediate relief montane subclasses was similar,while the area of subclasses of high and extremely high relief was less.2)Due to the spatial differences of water and heat conditions in mountainous areas,some grassland subclasses do not exist in particular environments.3)At the CSCS class level,most widely distributed subclasses was frigid perhumid rain tundra alpine meadow ( Ⅰ F36);cold temperate perhumid taiga forest ( Ⅱ F37) is the second;warm-perhumid deciduousevergreen broad leaved forest(Ⅴ F40)is ranked third and subtropical-extrarid subtropical desert(Ⅵ A6)had the smallest distribution area.The research results provide an objective scientific basis for the development and utilization of grassland,cultivation,protection and management policies,and the formulation of sound animal husbandry practice.