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以川西亚高山云杉人工林林地土壤为对象,采用磷脂脂肪酸(PLFA)法研究了4种不同林龄(50、38、27和20年)的人工林土壤微生物多样性和群落结构特征.结果表明:随着林龄的增加,土壤有机碳和全氮含量逐步增加;土壤微生物Shannon多样性和Pielou均匀度指数则呈现先增后减的趋势.土壤微生物总PLFAs量、细菌PLFAs量、真菌PLFAs量、放线菌PLFAs量以及丛枝菌根真菌PLFAs量均表现为随林龄的增加而增加.主成分分析(PCA)表明,不同林龄人工林的土壤微生物群落结构之间存在显著差异,其中,第1主成分(PC1)和第2主成分(PC2)共同解释了土壤微生物群落结构总变异的66.8%.冗余分析(RDA)表明,对土壤微生物群落结构产生显著影响的环境因子分别为土壤有机碳、全氮、全钾以及细根生物量.随着人工造林时间的延长,土壤肥力和微生物生物量增加,森林生态系统的恢复进程稳定.
In this study, soil microbial diversity and community structure characteristics of four plantations with different age (50, 38, 27 and 20 years) were studied by means of phospholipid fatty acid (PLFA) method in the forest soil of subalpine spruce plantations in western Sichuan. The results showed that the contents of soil organic carbon and total nitrogen increased gradually with the increase of stand ages, and the Shannon diversity and Pielou evenness index increased first and then decreased.The total amount of PLFAs, PLFAs and PLFAs PLFAs amount of actinomycetes and PLFAs amount of arbuscular mycorrhizal fungi all increased with the increasing of age.The principal component analysis (PCA) showed that there was a significant difference in soil microbial community structure among different age stands, Among them, the first principal component (PC1) and the second principal component (PC2) jointly explained 66.8% of the total variation of soil microbial community structure. The redundancy analysis (RDA) showed that the environmental factors that significantly affected the microbial community structure Soil organic carbon, total nitrogen, total potassium and fine root biomass.With the prolongation of artificial afforestation, soil fertility and microbial biomass increased, and the process of forest ecosystem restoration was stable.