海南海岸青皮林土壤微生物类群的数量特征

Quantitative characteristics of soil microorganism groups in Hainan coastal Vatica mangachpoi forest

为了从土壤微生物方面揭示海南石梅湾海岸青皮天然林更新的机理,对青皮林土壤微生物进行了调查分析。土壤调查采用5点取样法,分别于旱季和雨季对两个土层的根际土和根外土进行取样,并用MPN法分析了土壤中5个生理类群细菌的数量分布特征。结果表明:青皮林土壤中除尚未检测出亚硝化细菌外,其他4个生理类群细菌的数量彼此之间差别很大,其中氨化细菌的数量>>好气性自生固氮细菌>>反硝化细菌>>好气性纤维素分解细菌;根际土壤中的氨化细菌、反硝化细菌和好气性纤维素分解细菌数量比非根际土壤少,但好气性自生固氮菌数量则相反;下层土中氨化细菌的数量略高于上层土,但好气性自生固氮细菌、反硝化细菌和纤维素分解细菌多集中分布在上层土内。

In order to reveal the mechanism of natural regeneration in Shimei Bay coastal Vatica mangachpoi forest from the aspect of soil microorganism, the soil microorganisms in V. mcmgachpoi forest were investigated and analyzed. Five-point sampling method was used to take the soil samples in both dry and wet seasons form rhizosphere and non-rhizosphere soil, respectively, and the MPN was used to analyze the quantitative distribution of five physiological groups of bacteria in the soil. The results showed that nitrite bacteria was not found in the soil of V. mangachpoi forest, there were obvious differences among the quantities of the other four physiological groups of bacteria, the quantities of ammonifying bacteria 〉〉 aerobic nitrogens-fixing bacteria 〉〉 denitrifying bacteria 〉〉 aerobic cellulose decomposing bacteria; the quantities of ammonifying bacteria, denitrifying bacteria and aerobic cellulose decomposing bacteria were less in the rhizosphere soil than in the non-rhizosphere soil, but the quantity of aerobic nitrogens-fixing bacteria was opposite in the rhizosphere and non-rhizosphere soil; the quantity of ammonifying bacteria was slightly higher in the subsoil than in the upper soil, but quantities of the aerobic nitrogen-fixing bacteria, denitrifying bacteria and cellulose decomposing bacteria were more concentrated in the upper soil.