为探究海南热带雨林国家公园主要外来树种对土壤理化性质的影响,采用五点取样法对外来树种群落与次生林群落土壤进行采样,用化学方法对土壤理化性质进行测定。结果表明:次生林群落土壤pH值为4.79,低于桉树群落,高于其余外来树种群落。次生林群落土壤有机质含量为31.01 g/kg,全氮、磷、钾含量分别为1.08,2.27,1.83 g/kg,均高于外来树种群落土壤有机质全氮磷钾。速效钾测定显示,次生林群落低于外来树种群落;但次生林群落铵态氮含量均高于外来树种群落。速效磷含量方面,次生林群落低于马占相思和桉树群落,高于加勒比松群落,与橡胶群落没有显著性差异。硝态氮测定显示,次生林群落与橡胶群落没有显著性差异。引入外来树种使土壤有机质和全氮钾磷总含量降低,游离态部分养分含量提升;桉树减弱土壤酸性,其他外来树种倾向加大土壤酸性趋势。

To explore the effects of main exotic tree species on soil physicochemical property in Hainan tropical rain forest national park.Soil sampling of exotic tree species community and secondary forest community was conducted by five-point sampling method,and determination of soil physicochemical property was conducted by chemical method.The results showed that the soil pH of secondary forest community was 4.79,which was lower than that of eucalyptus community and higher than that of secondary forest community.The soil organic matter content of secondary forest community was 31.01 g/kg,and the TN、TP、TK contents were 1.08 g/kg,2.27 g/kg and 1.83 g/kg,respectively,which were higher than those of exotic tree species community.Determination of ak showed that secondary forest community was lower than exotic tree species community.The NH₄⁺ content of secondary forest community was higher than exotic tree species community.In ap content,secondary forest community was lower than Acacia mangium and eucalyptus community,higher than Pinus caribaeamorele community,and there was no significant difference with Hevea brasiliensis community.Determination of NO₃^- showed,there was no significant difference between secondary forest community and Hevea brasiliensis community.The introduction of exotic tree species reduced the contents of soil organic matter and total nitrogen,potassium and phosphorus,and increased the contents of free soil nutrients.Eucalyptus weakened soil acidity while other exotic species tended to increase soil acidity.