广西弄拉岩溶植被不同演替阶段的主要土壤因子及溶蚀率对比研究

植被是土壤形成过程中最活跃的因素 ,在同样气候条件下又是最重要的因素 ,植被的演替改变了土壤的理化性质 ,促进了成土作用。植被的正向演替可改善土壤 A层的理化性状 ,降低容重 ,增加孔隙度、含水量和有机质含量 ;而 B层理化性状在演替初期得到改善 ,后期 (乔林期 )却明显下降 ,容重增加 ,孔隙度、含水量和有机质含量大大降低。土壤 p H值随演替进展逐渐降低。Mg含量随正向演替而降低 ;Ca因植物的作用而呈现复杂性。土壤 CO2 的变化也很复杂 ,表层 CO2 随正向演替明显增加 ,但当(青冈林土 )孔隙度很大时有利于 CO2 的逸出而大大降低 ;深层 CO2 与土壤孔隙度、含水量一致 ,初期随正向演替增加 ,到乔林期又降低。地表溶蚀率随植被正向演替 ,先降低后增加 ;土壤中岩石的溶蚀率随演替而增加 ,与 Ca、Mg含量 ,p H值成反比 ,与土壤有机碳、CO2 浓度成正比 ;植被进展演替有促进潜蚀的作用 ,演替初期表层溶蚀率较深层高 ,到乔林阶段后深层较高。岩石的溶蚀率还受土壤含水量、孔隙度等多种因素的影响。

The comparison of properties of Karst soil and Karst erosion ratio under different successional stages of Karst vegetation in Nongla, Guangxi

The deterioration of karst ecosystems in Guangxi is very serious, which hinders local economic development and has become one of the key environmental problems in the province. In order to look for the best way to rehabilitate the vegetation in karst areas and achieve sustainable development, it is necessary to study the change of environmental factors during the process of succession. In this paper, selected properties of karst soils, including water content, soil porosity, soil organic C, pH value, soil ...