海南儋州5种林地土壤微生物生物量碳对比

Comparative Studies on Soil Microbial Biomass Carbon in Rubber Forest and Secondary Forest in Danzhou,Hainan Province

采用时空替代法,选取5a（幼龄林）、10a（中龄林）、30a（老龄林）的橡胶林、30a桉树林和热带次生林,研究不同树龄橡胶林土壤微生物生物量碳含量的分布特征,不同林型土壤微生物生物量碳含量的差异及其随季节的变化。结果表明：5种林型下的土壤微生物生物量碳由高到低依次为中龄林〉幼龄林〉次生林〉老龄林〉桉树林,中龄林、幼龄林和次生林3种林型和另外2种林型之间均有显著差异（p〈0.05）;旱季到雨季,5种林型土壤微生物生物量碳含量逐渐升高,雨季明显高于旱季;土壤微生物生物量碳含量随土壤深度逐渐降低,5种林型下0～10cm和20～30cm的土层的微生物生物量碳均有显著差异;不同林型下微生物生物量碳与土壤全氮、全磷、全钾、有机碳、含水率的相关关系均不显著。

The rubber forest with the ages of 5a（young）,10a（middle-age）,30a（old growth rubber forest）,and eucalyptus forest with the age of 30 a,as well as tropical secondary forest were selected to investigate the vertical variations of the soil microbial biomass carbon（SMBC）,and the differences of SMBC content and the seasonal changes in different forests.The results showed that SMBC of five forest types was in the order of middle age forest young forestsecondary forestold growth forest eucalyptus forest.The middle age forest,young forest and secondary forest were significant different from the other two forest types（p〈0.05）.The contents of SMBC of five forest types increased from dry to the rainy season,and the rainy season was significantly higher than the dry season.SMBC decreased with soil depth,and significantly different between 0-10 cm and 20-30 cm soil layer under five types of forests.There were no significant correlations between SMBC and soil total nitrogen,total phosphorus,total potassium,organic carbon,water content under different forest types.