秦岭山区飞播纯林与混交林下土壤养分状况分析

通过对秦岭山区飞播油松纯林和油松、槲栎混交林下养分状况的分析，结果表明：尽管纯林和混交林都有富积养分的效应，但两者对养分的影响是不同的，混交林在对有机质、全氮、速效氮的影响上优于纯林，相反纯林对土壤磷素的影响较大。在0～20cm土层中，混交林下土壤有机质、全氮、速效氮、全磷、速效磷的含量与纯林下各养分含量的相对差值分别为89．9％、42．9％、128．1％、7．3％、-44．7％。由于混交林能积累较多的有机质，所以混交林比纯林更有利于改善土壤肥力。

Analysis of Soil Nutrient Status Quo under the Aerial-Seeded Pure and Mixed Forests in Qinling Mountain

Analysis of soil nutrient under the aerial seeded pure forest of Pinus tabulaeformis and mixed forest of Pinus tabulaerformis with Q. aliena indicated that two types of forest had different outcomes although nutrients accumulated under two types of conditions. Mixed forest produces superior influences on organic matter, total nitrogen, and available nitrogen in soil to pure forest, but reverse regarding phosphorate in soil under two types of forest. Nutrient differences in the layer of 0 to 20 cm between pure forest and mixed forest with respect to organic matter, total nitrogen, available nitrogen, total phosphorate, available phosphorate were, respectively, 89%, 42.9%,128.1%, 7.3%, and -44.7%. Mixed forest that can accumulate more nutrients in the soil proves to be much effective to improving soil fertility.