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  

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

作　　者：李恩香[1,2] 蒋忠诚[1] 曹建华[1] 姜光辉[1] 邓艳[1] 

机构地区：[1]中国地质科学院岩溶地质研究所,国土资源部岩溶动力学开放实验室,桂林541004 [2]浙江大学生命科学院,杭州310029

出　　处：《生态学报》2004年第6期1131-1139,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 (3 0 0 690 0 5 ) ;广西自然科学基金资助项目 (3 0 0 60 0 2 2 ) ;国土资源部重点科技项目资助项目 (2 0 0 0 2 0 8)~~

摘　　要：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 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 CO_2, the content of Ca and Mg, and karst erosion ratio under plant communities representing six successional stages in Longla village, Guangxi, China are described. The stages are bare rock, grass, grass-shrubs, shrubs, young trees and climax forest.The study shows that vegetation can accelerate the formation of karst soil, and determine various soil properties. Progressive succession can improve the physical conditions, for example raising the soil porosity and water content and reducing soil bulk density in the upper soil horizon (5～15cm). However, the changes are more complex in the lower horizons (25～35cm), where increased soil bulk density and reduced soil porosity can occur at the forest stages. The changes in the chemical properties of karst soil are also complex during the succession. With the increased vegetation cover, soil organic C increases in the upper horizon (5～15cm); but in the lower horizon (25～35cm), it increases obviously in the earlier stages (from bare rock to shrubs) and may then decrease at the tree/forest stages. The pH and Mg content decrease with successional advancement. Changes in Ca content are complex, with the element being absorbed and then released by plants during succession.The soil CO_2 was measured at 20cm and 50cm depth. In general, the content of soil CO_2 at 50cm depth is higher than that at 20cm. The soil CO_2 in the upper horizon (20cm) increases during succession, but may be lower when the soil porosity is very high. In the lower horizon (50cm), this increase

关 键 词：广西弄拉 植被演替 土壤因子 溶蚀率 

分 类 号：Q948.113[生物学—植物学]