滇东南峰林湖盆区土壤理化性质的空间异质性分析

Spatial Heterogeneity Analysis of Soil Physical and Chemical Properties in Southeast Yunnan Peak Forest-lake Basin

为了解喀斯特地区退耕还林过程中不同植被恢复阶段的土壤理化性质特征,于研究区坡面的不同坡位设置样地:坡耕地(坡脚)、云南松人工林(下坡)、次生林(中坡)、石灰岩灌丛(上坡)。采用野外取样与室内分析相结合的方法对土壤理化性质进行了调查,并对其各项理化性质指标进行了皮尔逊(Pearson)相关性分析和主成分分析,最后,采用土壤水文结构功能模型评价滇东南普者黑峰林湖盆区次生林恢复植被的土壤水文结构功能。结果表明:研究区土壤孔隙度、毛管持水量状况大致为次生林>云南松林>石灰岩灌丛>坡耕地;云南松人工林和次生林有机质、全氮、全磷、全钾等元素均较高,p H较低。相关性分析表明,土壤含水率、有机质、全氮、全钾、交换性镁与土壤的其他理化性质有较强的相关性,是喀斯特地区保持土壤理化性质的主要因子。主成分分析表明,土壤总孔隙度、非毛管孔隙度、含水率、有机质、全磷、交换性镁、交换性钙、pH是土壤理化性质的关键因子,是养分循环和流动的载体。土壤水文结构功能指数的计算结果表明,次生林(0.68%)>云南松林(0.43%)>石灰岩灌丛(0.26%)。

In order to investigate the soil physical and chemical characteristics in different vegetation restoring stages during the process of returning farmland to forest in Karst area,this paper set up sample plots in different slope positions at the studying area：Slope land,Yunnan pine plantation （downhill）,secondary forest （medium slope） and limestone shrub （uphill）.Soil physical and chemical properties were investigated by means of field sampling combined with indoor analysis.Pearson relativity analysis and principal component analysis were carried out.Finally,the function model of soil hydrological structure was used to evaluate the soil hydrological structure of the Puzhehei restoration vegetation.Results showed that the soil porosity and water holding capacity in the studying areas were mainly secondary forest Yunnan pine limestone shrub sloping farmland.The organic matter,total nitrogen,total phosphorus,total potassium and other elements of Pinus yunnanensis plantation and secondary forest were higher,and their pH was lower.Correlation analysis showed that soil moisture content,organic matter,total nitrogen,total potassium,exchangeable magnesium and other physical and chemical properties of soil were strongly correlated,and the main factors of maintaining soil physical and chemical properties in Karst area.Principal component analysis showed that soil total porosity,non capillary porosity,water content,organic matter,total phosphorus,exchangeable magnesium,exchangeable calcium and p H were the key factors of soil physical and chemical properties,and the carriers of nutrient cycling and flow.The calculation results of soil hydrological structure function index indicated thatsecondary forest （0.68%） Yunnan pine forest （0.43%） limestone shrub （0.26%）.