梵净山垂直带土壤的发生学特性与系统分类研究

Genetic Characteristics and Taxonomic Classification of Vertical Soils in the Fanjingshan Mountain

为了解贵州东北部山地土壤的发生学特性及土壤分布,选择梵净山地区采集了不同海拔高度的13个代表性土壤剖面,分析了其成土环境、土壤风化强度的垂直变化,鉴定了区内土壤的主要诊断层、诊断特性,并根据中国土壤系统分类对研究区土壤类型进行了分类。结果表明,随着海拔的增加,区内土壤温度状况由热性转变为温性,水分状况逐渐由湿润向常湿润转变。梵净山地区土壤风化较弱,土壤中存在较多的2∶1型矿物,土壤脱硅富铁铝化处于中下水平。土体厚度、土壤黏粒、全铁、游离氧化铁含量、铁游离度随海拔增加而下降,砾石含量、黏粒CEC、土壤ba值、黏粒Sa值随海拔增加而上升,部分土壤出现明显的黏化。区内土壤酸化明显,多数土壤的pH在5.5以下,部分土壤的铝饱和度超过了60%,土壤的平均铝饱和度随海拔增加而下降。研究区土壤黄化非常明显,土壤色调主要为10YR。共检出淋溶土、雏形土和新成土3个土纲,5个亚纲、8个土类和12个亚类,土壤类型主要由淋溶土和雏形土组成。亚纲在海拔高度变化上有一定的分布规律,随着海拔的上升,由湿润淋溶土、湿润雏形土向常湿淋溶土、常湿雏形土转变。

To understand the genetic characteristics and distribution of mountain soils in the Northeast Guizhou,thirteen representative soil profiles were sampled from different altitudes in the Fanjingshan Mountain region to discuss vertical changes of soil forming environment and weathering intensity, and to characterize main diagnostic horizons and diagnostic characteristics of the soils in the region. And soil types in the region were classified according to the Chinese Soil Taxonomy. With the increase of altitude, soil temperature regime in the region changed from the thermic to the mesic, meanwhile soil moisture regime gradually changed from udic to perudic. On the whole, soil weathering in the Fanjingshan Mountain region was weak. There were more 2∶1 type minerals in the soils, and desilication and allitization of the soils were mainly moderate to weak. Soil thickness, contents of soil clay, total iron, free iron oxide and free degree of iron oxide decreased with increasing altitude, while contents of gravel, CEC, weathering and leaching coefficient（ba value） of soil and silica alumina ratio（Sa value） of clay increased with the increasing altitude.Some soil had obvious claying. Acidification of soil in the region was obvious, and pH value of most soil was less than5.5. Saturation of exchangeable Al in some soils was more than 60%, and the average Al saturation of soil decreased with increasing altitude. Soil yellowing was very obvious in the region with their hue mainly of 10 YR. A total of three soil orders（Argosols, Cambosols, and Primosols）, five suborders, eight soil groups and twelve subgroups were identified. The soil type in this region was mainly composed of Argosols and Cambosols. Soil suborder was changed with the altitude. With increasing altitude, it changed from Udic Cambosols and Udic Argosols to Perudic Cambosols and Perudic Argosols.