区域性皆伐抚育作业对沙柳林地土壤养分空间异质性的影响*

针对毛乌素沙地沙柳林以区域性皆伐作业为主的采伐方式,研究皆伐干扰对林地土壤养分和有机质含量的空间变异特性的影响,为开展灌木林生态采伐理论奠定前期基础。在对照设立皆伐和未采伐两组样地上,按照空间格局分析技术中多样点、小支撑的取样原则,用土钻取样地表层(0~15 cm)土样,实验室测定土样的全氮、全磷、全钾和有机质碳的含量;运用SPSS和GS+软件进行数据分析。数据结果如下:受皆伐干扰的样地养分含量高于未采伐样地,受皆伐干扰的样地的土壤全氮和有机质含量升高最为明显,平均值为未采伐样地的1.47和1.12倍。两者表层全氮、全磷和全钾的含量均能很好地拟合成球状模型;皆伐扰动并未使土壤养分的空间自相关度降低,空间自相关性引起的异质性占总异质性的75%以上;采伐干扰使磷、钾养分的变程减小(分别降低26.5%和27%),林地养分呈现出中小尺度的空间变异特征;通过土壤养分空间异质性分析得出:对沙柳灌木林进行区域性皆伐的抚育措施,可使林地的土壤环境得以改善,利于沙柳林的可持续经营。

Regional Clear Cutting Operation on Soil Nutrient of Salix psammophila Forest Short-term Disturbance Characteristics*

For the way of cutting of salix mongolica given priority to regional clear cutting operation in Maowusu sandy land, cutting interference on woodland soil nutrients and spatial variation characteristics of organic matter content is studied, and the early basis of the shrub ecological cutting theory is made foundation. In contrast to two set of sample of clear cutting and clay surface (0 ~ 15 cm) soil samples are sampled by drilling, the total nitrogen, total phosphorus, total potassium and organic no cutting, according to the sampling principle of diversity points and small support in spatial pattern analysis techniques, the carbon content of soil samples is measured in the laboratory. Data analysis is made by SPSS and GS + software, the results are as follows: by the to nutrient content of sample is higher than no cutting sample, the rise of total nitrogen and organic matter content of sample soil on clear cutting interference is most obvious, witch the average is 1.47 and 1.12 times to no cutting. Both total nitrogen, total phosphorus and total potassium content of the surface can be fitted synthetic spherical model; Clear cutting disturbance does not reduce the autocorrelation of the soil nutrient space, heterogeneity caused by space autocorrelation is more than 75% of the total heterogeneity; The cutting interference reduce the variation of phosphorus and potassium nutrient (reduced 26.5% and 27% respectively), forest land nutrient shows the characteristics of medium and small scale of space mutation; the spatial heterogeneity of soil nutrients is analyzed, tending measures for regional salix shrub forest can be used to improve forest soil environment, and the sustainable management of salix shrub forest.