盐生植被演替对土壤微生物碳源代谢活性的影响

摘要

Biolog method was used to reveal the distinction of carbon source metabolic activities in Yellow River Delta.The samples indicated three succession phases of salt vegetation types,which included "bare board-severe salt tolerant communities (Saline Seepweed,Angiospermae)-mild salt communities (Imperata and A.Venetum.)".The results showed that the soil quality and the carbon source metabolic activities of soil microbial had the trend of significant and continuous improvement along with the succession of salt vegetation types (P＜0.05),and the carbon source metabolic activities of soil microbial had the trend of extremely significant enhance (P＜0.01).Shannon-wiener index,Richness index,Simpson index and Pielou evenness index were increased with the succession of salt vegetation types and had the significant correlation with total nitrogen,available nitrogen and conductivity (P＜0.05).While those indexes had a significant negative correlation with soil salinity (P＜0.01).Along with the succession of salt vegetation in the Yellow River Delta,the types and amounts of utilized carbon source were increased.Total nitrogen and available nitrogen were the crucial factors which significantly stimulated carbon metabolic abilities.While,soil salinity was the negative control factor.%采用Biolog-Eco微平板法,研究了黄河三角洲地区不同盐生植被下土壤微生物的碳源代谢特征,并探讨了土壤微生物碳源代谢水平与盐生植被演替的关系.结果表明,黄河三角洲土壤质量随盐生植被正向演替呈现逐渐改善的趋势,盐生植被从“裸地-强耐盐植物-轻耐盐性植物”演替过程中,土壤微生物碳源代谢活性极显著增强(P＜0.01).土壤微生物群落的Shannon-Wiener指数、丰富度、Simpson指数和Pielou均匀度指数按演替顺序逐渐增加,且与全氮、碱解氮呈现显著(P＜0.05)正相关,与土壤盐度呈现极显著负相关(P＜0.01).随着“光板地-强耐盐植物-轻度耐盐植物”的演替,微生物利用的碳源种类不断增加,所利用的各类碳源数量上也越来越接近.全氮(Total nitrogen)和碱解氮(Available nitrogen)显著促进了微生物的碳源代谢活性,土壤盐度则显著抑制了土壤微生物的碳源代谢活性.