横断山区土壤区划

SOIL REGION ALIZATION OF THE HENGDUAN MOUNTAINOUS REGION

本文概述了横断山区土壤区划的历史,提出了该区土壤区划的原则和土壤区划单位系统(土壤地带—土区—土片)以及新的区划方案,并侧重论述了各土壤地带与土区的成土环境特点、土地利用方向及其代表性的山地土壤垂直带谱。

According to the horizontal and vertical differentiations of hydrothermal condition and relative soil forming process and the regional difference of land-use, 3 soil zones, 11 soil regions and 25 soil sections were divided in the Hengduan Mountainous Region.Three class units in the soil regionalization system are divided according as follo-wingsi1. Soil zone based on the horizontal differentiation of hydrothermal condition and relative types of compo-pattern of vertical soil belts in mountains. It's named after the administrative division and the series of great soil groups. 2.Soil region based on the regional differences of compo-pattern group of vertical soil belts in mountains within the soil zone. It's named after the mountains and rivers and the great soil groups dominated in mountains.3.Soil section based on the compo-patterns of vertical soil belts with relation to geomorphologic condition within the soil region. It's named after the local county.Finally, the paper summarized emphasis on geographic distribution, soil forming environment, main soil genetic types and their vertical structure, regional agricultural development direction of 3 soil zones ( i. e., 1 . Red earth zone in northwestern Yunnan and southwestern Sichuan, 2 . Drab-brown soil zone in western Sichuan, 3 . Alpine soil zone in northwestern Sichuan, ) and 11 soil regions.