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目前,西南桦(Betula alnoides)和马尾松(Pinus massoniana)均是广西红壤区大规模种植的人工林树种。为了分析和评价这两个树种对土壤肥力和生态质量的影响,本文采用了稀释平板法和氯仿熏蒸提取法等传统方法分析了两种人工林土壤可培养微生物数量、微生物量碳、微生物量氮、涉及土壤碳、氮、磷循环相关酶活性等表征微生物活性的指标。同时,采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术分析了两种人工林土壤细菌多样性。结果表明,西南桦人工林土壤中可培养真菌数量与马尾松人工林虽无明显差异,但可培养细菌和放线菌数量均明显高于相应的马尾松人工林。土壤中β-葡萄糖苷酶、磷酸酶和蛋白酶活性在两种人工林之间虽无明显差异,但西南桦人工林各土层土壤的微生物生物量碳、氮指标均优于对应的马尾松林,表现出比马尾松更优的生态效果。此外,西南桦人工林土壤中各土层细菌多样性指数(Shannon-Wiener index)均高于相应的马尾松人工林土层。综上,比马尾松相比,西南桦是更有利于提高红壤区土壤肥力和维持林地土壤生态质量的造林树种。
At present, both Betula alnoides and Pinus massoniana are large-scale planted tree species in red soil region of Guangxi. In order to analyze and evaluate the effects of these two tree species on soil fertility and ecological quality, the traditional method of dilution plate and chloroform fumigation was used to analyze the quantity of soil culturable microorganism, microbial biomass carbon, microbial biomass nitrogen , Which is related to the activity of enzymes related to cyclic carbon, nitrogen and phosphorus cycling. Meanwhile, the bacterial diversity of two kinds of plantations was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that the quantity of culturable fungi in the soil of Betula alnoides plantation was not significantly different from that in the Pinus massoniana plantation, but the number of culturable bacteria and actinomycetes was significantly higher than that of the corresponding Pinus massoniana plantation. Soil β-glucosidase, phosphatase and protease activity in the two kinds of plantations although no significant difference, but the Betula alnoides soil microbial biomass carbon and nitrogen indicators are better than the corresponding Pinus massoniana forest, Show better ecological effect than Masson pine. In addition, the Shannon-Wiener index of each layer of Betula alnoides plantation soil was higher than that of corresponding Pinus massoniana plantation soil. In summary, Betula albosine is an afforestation tree that is more conducive to improving soil fertility and maintaining the ecological quality of forest soil than that of masson pine.