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运用氯仿熏蒸法和实时荧光定量PCR(Real-time PCR)法,检测喀斯特峰丛洼地原生林上、中、下坡位各土层(淋溶层:A层0~10 cm;过渡层:AB层30~50 cm;淀积层:B层70~100 cm)中土壤微生物生物量碳、氮(SMBC、SMBN)及微生物(细菌和真菌)丰度的变化,揭示坡位和土层对土壤微生物生物量和丰度的影响.结果表明,坡位和土层及其交互作用均对土壤微生物生物量及丰度具有显著影响(P<0.05).具体表现为,土壤微生物生物量与丰度均随土层深度的增加而降低;A层SMBC在下坡位表现最高,均高于上坡位(P<0.05),AB层、B层SMBC在中坡位最高;SMBN均在下坡位表现为最高,显著高于上坡位(P<0.05);除B层细菌丰度、AB层真菌丰度在各坡位间无显著差异外,均表现为中坡位最高(P<0.05).逐步回归分析结果表明,在坡位和土层的影响下,有机碳、碱解氮与p H、碱解氮与速效磷、速效钾分别是SMBC、SMBN、细菌丰度、真菌丰度的主要影响因子.
Chloroplast fumigation and Real-time PCR were used to detect the soil layers of the upper, middle and downhill slope in the karst peak-cluster depressions (leaching layer: 0-10 cm in layer A; transition layer: AB (30 to 50 cm in thickness and 30 to 50 cm in depositional layer: 70 to 100 cm in layer B). The changes of soil microbial biomass carbon (SMBC), SMBN (SMBN) and microbial (bacteria and fungi) Microbial biomass and abundance.The results showed that both slope position and soil layer and their interaction had a significant effect on soil microbial biomass and abundance (P <0.05), which showed that soil microbial biomass and abundance (P <0.05). SMBC in the AB and B layers was the highest in the middle slope. SMBN all showed the highest slope in the downhill (P <0.05). Except for the abundance of layer B and the abundance of AB layer, there was no significant difference among the four slope positions (P <0.05) Regression analysis showed that under the influence of slope position and soil layer, organic carbon, available nitrogen and p H, available nitrogen, available phosphorus and available potassium were SMBC, SMBN, bacterial abundance, fungi Main factors of degree.