藏东南色季拉山酸性棕壤土养分含量的分布特征

Distribution Characteristics of Soil Nutrient Content in Mountain Acid Brown Soil in Sejila Mountain,Southeast Tibet

土壤养分是森林生态系统的重要组成成分,其含量高低对林地的生产力具有决定性的影响。本文以色季拉山海拔3 900~4 100m区域为研究对象,利用Origin 9.0、SPSS 20.0等软件,分析了冷杉、云杉、高山柏等11种植被林下0~10cm土层和10~20cm土层的土壤全氮、全磷、全钾及无机氮、有效磷和速效钾的含量以及养分的空间分布状况。结果表明,供试的11种植被下土壤全量氮、磷、钾大多数,无机氮大多数,有效磷、速效钾含量全部表现为0~10cm土层>10~20cm土层,表明土壤养分具有表聚作用;土壤养分含量具有空间异质性,土壤全氮、全磷含量变异表现为0~10cm土层<10~20cm土层,而全钾和有效磷和速效钾含量变异性表现为0~10cm土层>10~20cm土层,无机氮在供试两个土层变异性差异不显著,表明0~10cm土层的无机养分更易受外界环境的影响;在0~10cm土层和10~20cm土层中,土壤无机氮占全氮量分别为15.41%~20.45%和16.01%~23.79%,有效磷占全磷量分别为0.152 1%~0.234 3%和0.098 9%~0.158 3%,速效钾占全钾量分别为2.620 8%~4.054 1%和1.564 3%~2.268 2%。

Soil nutrient is an important component of forest ecosystem, and its content has a decisive influence on the productivity of forest land. In order to elucidate the nutrient variation of mountain acid brown soil and its response to vegetation, soil total nitrogen （TN）, total phosphorus （TP）, total potassium （TK） and inorganic ni-trogen （Nmin）, available phosphorus （ AP） and available potassium （ AK） in soil layer of 0 -10cm and 10 - 20cm of 11 plants were analyzed by using origin 9. 0, SPSS 20. 0 at altitude ranging 3 900 to 4 100m of Sejila mountain. The results showed that the content of TN,TP,TK and Nmin, AP and AK in soil layer of 0 -10cm were found more than those in 10 -20cm,indicating the soil surface gathering characteristics of the soil nutrient content. The soil nutrient content has higher spatial heterogeneity, the spatial variability of soil TN, TP content were obvious,and that in 0 -10cm layer was lower than that in the 10 -20cm layer,but the variation of TK and AK content under the soil were 0 -10cm〉10 -20cm,while the variation of inorganic nitrogen in the tested soil was not significant,which showed that in 0 -10cm soil layer,the inorganic nutrients were more susceptible to the external environment. In soil layer of 0 -10cm and 10 -20cm,the values of Nmin/TN were 15. 4 1 % -20. 4 5 % and 16. 01% -23. 79%,respectively,while the value of AP/TP were 0. 152 1 % -0. 234 3 % and 0. 098 9 % - 0. 158 3%,and AK/TK： 2. 620 8% -4. 054 1% and 1. 564 3 % -2. 268 2%,respectively.