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以茂兰国家级自然保护区内三种植被(原生林、次生林、灌木林)下的土壤为研究对象,探讨了小生境土壤微生物数量、微生物量碳(BC)、微生物量氮(BN)、微生物熵(qSMBC)、基础呼吸及代谢熵(qCO2)的变化特征。结果表明:微生物数量、BC、BN、基础呼吸、qSMBC基本呈现石沟>土面的趋势,qCO2则表现为土面>石沟,即石沟土壤的各项微生物活性指标基本都优于土面,因而在喀斯特生态系统的自然恢复过程中,应优先利用石沟小生境;土壤微生物量碳氮、qSMBC、基础呼吸、真菌数量均随植被逆行演替(原生林→次生林→灌木林)大致呈现下降趋势,指示研究区土壤质量随植被退化而下降,土壤碳丢失;细菌和放线菌数量在退化过程中却有不同程度的增加,这与细菌和真菌之间的养分竞争、凋落物中的木质化纤维成分增多有关。
Taking the soil under three kinds of vegetation (primary forest, secondary forest and shrub forest) in Maolan National Nature Reserve as research object, the effects of soil microbial biomass, microbial biomass carbon (BC), microbial biomass nitrogen Changes in microbial entropy (qSMBC), basal respiration and metabolic entropy (qCO2). The results showed that the number of microbes, BC, BN, basic respiration and qSMBC basically showed the tendency of stone ditch> soil surface while qCO2 showed that soil ditch> stone ditch, that is, the soil microbial activity indicators of stone ditch soil were better than those of soil surface , Therefore, the gully niche should be prioritized in the process of natural restoration of karst ecosystem. The soil microbial biomass carbon and nitrogen, qSMBC, basic respiration and fungi all appeared in the reverse succession (primary forest → secondary forest → shrub forest) Indicating that the soil quality in the study area decreased with the degradation of vegetation and the soil carbon was lost. The numbers of bacteria and actinomycetes in the degradation process increased to some extent, which was in competition with the competition of bacteria and fungi, Lignification of the increase in the composition of the fiber.