贵州喀斯特石漠化地区荒地土壤理化性质及环境效应研究

【作者】 王金乐；

【导师】 林昌虎； 何腾兵；

【作者基本信息】 贵州大学 ， 环境科学， 2008， 硕士

【摘要】 本研究根据贵州省区域地质地貌、气候条件和石漠化发生发展现状,把贵州省喀斯特石漠化区域分为西部、西南部、东部、南部四个研究区域。应用典型性分析等方法,结合当前对石漠化分级分类的划分,在这四个研究区域内分别采集了不同石漠化程度和不同生态背景条件下的土壤样品。本研究经分析土壤理化性状变异特征,结合其与石漠化发展过程的相关关系,深入探讨喀斯特石漠化区域荒地土壤本底状况及其环境效应,获得的主要结论如下:(1)石漠化过程中,极强度石漠化荒地土砂粒含量较高,而细粘粒含量相对较低,且随石漠化程度的加剧而降低。随生态模式:林地→草地→农用地→荒地的变化,其土壤细粘粒含量呈现下降的趋势,而东部及南部砂粒、粗粉粒及细粘粒的含量基本上较为平均。粘粒含量随着土壤剖面层次的加深而增加。(2)随着石漠化程度越强,土壤侵蚀度越大,其有机质含量也随之减少,且西部高于西南部土壤有机质含量。各生态模式下的有机质含量表现为荒地＜草地＜农用地＜＜林地,土壤剖面结构表层土壤有机质含量A＞＞B＞C层的含量,但B、C层变化幅度很小。(注:＜＜为远远小于;＞＞为远远大于)(3)土壤全氮、碱解氮、全磷、全钾及速效钾含量随着极强度石漠化到无明显石漠化逐步减少,且变化趋势越来越小,而土壤速效磷并未表现相同的变异规律。且贵州不同地区荒地土壤有机质及氮、磷、钾素含量:西南部＞西部。(4)贵州喀斯特石漠化地区的土壤全氮及碱解氮含量有:林地＞＞农用地＞草地＞荒地,而土壤全磷、全钾和速效磷含量是由于随着林地→草地→农用地→荒地这种生态模式的变化,速效钾未见类似规律。(5)土壤剖面上,氮、磷、钾素含量表现为:林地＞草地＞农用地＞荒地,其中以林地各指标含量在剖面上的变化最为剧烈。(6)土壤粘粒与有机质、全氮、碱解氮、全磷、速效磷、全钾、速效钾间均存在着显著正相关关系;有机质与全氮、碱解氮和速效磷表现为显著正相关关系,与全钾、速效钾均呈现极其显著的正相关关系;土壤粗粉粒、砂粒分别与有机质、全氮和碱解氮之间没有明显的相关关系。(7)建立了贵州喀斯特石漠化地区荒地土壤理化指标。随着石漠化程度由无明显石漠化向极强度石漠化发展,各指标均呈现明显的降低趋势,且变异越微弱。不同石漠化程度土壤氮、磷、钾素指标可以作为判断石漠化生态环境的一个营养指标。(8)随着撂荒时间的增长,其各项理化指标均有提高,质地也趋于良好。在自然条件下,随着撂荒时限推移对荒地进行再利用是可行的。从而提示我们在荒地土壤恢复问题上,可以从荒地还林还草方向上着手,兼备生态环境效应以及农业经济效益,适时适当利用已恢复的荒地。(9)荒地相较于其他生态模式,其质地以及有营养物质基础都较差。(10)荒地土地的生态“恢复”是一个自然演替过程,演替速度慢,时间过程长,某些环节还因具有不可逆性而无法恢复,因此进行环境恢复的同时也要进行环境的重建。从荒地还草还林着手,改善荒地土壤环境;政府部门加强土地利用管理,消除人为破坏;加大宣传力度广泛普及石漠化效应知识、采取一系列的生物措施等方法进行其喀斯特石漠化地区的生态环境恢复及重建。更多还原

【Abstract】 According to the geological physiognomy, climatic conditions and the actuality of desertificational development, in this research, karst desertification region was classified west, southwest, east and north as four investigation area This research applicated the way of typical analysis and combined with the current classified demarcation of rocky desertification to collect edaphic sample under different rocky desertification and different ecological background within four research region. This research analyzed the correlation ship between wasteland edaphic physical and chemical characteristics property and rocky developing process by analyzed the variation of edaphic physical property ,in order to investigate the ecological environmental effect of background value in karst rocky desertification region. The main conclusions have concluded as follows:(1)In the process of rocky desertification, higher percentage of sand but cosmid soil exist in grains extreme intensity rocky desertification, and the content show a descend trend with the development of rocky desertification. Moreover, the percentage of cosmid soil declined in the order of ecology which from woodland, lawn, plough to wasteland. The content of edaphic sand, coarse dust and cosmid are basically uniform in the eastern part and the southern part of Guizhou and the cosmid increased fallow with deepen of cross section.(2)In the process of rocky desertification, soil provided with low percentage of organic matter under serious erosion, with which the percentage of organic matter is higher in western area than it in southwestern region. The content of organic matter in different ecological style shows in correct order is woodland, plough, lawn and wasteland, and woodland content far more than plough, lawn and wasteland. Under the edaphic section of the organic matter in bedding plane content is far more than it in the B and C bedding plane. Moreover between B and C bedding plane, variational amplitude is week.(3)Edaphic nitrogen phosphorous and potassium, but active phosphorous express no variation law at different area of Guizhou, edaphic organic, nitrogen, phosphorous and potassium of wasteland in southwest is are more than which in west.(4)The content of woodland edaphic nitrogen is the highest in different ecological style, and the content of plough, lawn and wasteland are as follow. Additionally the regulation of phosphorous and potassium except active potassium shows that woodland content the most part and the. lawn, plough and wasteland are as follow.(5)Under the edaphic section, the content of nitrogen ,phosphorus and potassium show the law that woodland>lawn>plough>wasteland, in which the change of woodland are the most tempestuously under the edaphic section.(6) Edaphic cosmid correlate closely with organic, nitrogen, phosphorus and potassium. Edaphic organic correlate closely with nitrogen and phosphorus, and correlate normally potassium. There’s no relationship beyond coarse dust and organic, nitrogen, and as the same beyond sand and organic, nitrogen.(7) It established a edaphic index of heath lands in Guizhou karst rocky desertification region. It is shows the orderliness that with the development of rocky desertification which beginning from inconspicuous extent to extreme degree each index present a obvious depressed tendency and the variation is faintness. The edaphic index of wasteland in Guizhou karst rocky desertification region could be considered as a edaphic judgment of nutrition of karst ecological environment.(8)During the process of abandoned time limit, the standard of edaphic physiochemical index has risen and its texture has gone well either. Under the natural condition, it is feasible to utilize wasteland after a period of recover, which call attention to us that we could recover wasteland with plants. Considered with both ecological environmental effect and agriculture economic effectiveness, we should utilize recovered wasteland properly.(9)Compared with other ecological style, the edaphic texture and the foundation of nutrientsubstance are the worst.(10)To renew the ecological environment of wasteland is such a process which is a lengthy natural succession. The reconstruction of ecological environment is of the most important thing which base on the renewing of ecological environment. As a result, we should take drastic measures to rebuilt environment while we resume it. We should commence improving the edaphic environment of wasteland, by recovering with lawn and woodland, wasteland; government ought to enhance the management of territorial utilization, in order to eliminate factitious breaks; to reinforce the propaganda and to impart generally the knowledge of rocky desertification effect and to adopt a serials of ecological reconstruction to complete the environmental recovering and rebuilding in karst rocky desertification region.更多还原