为全面了解大气氮沉降条件下滨海湿地土壤微生物碳源利用特点，本研究在江苏盐城滨海湿地建立模拟氮沉降实验平台，设置N1 (N，0 g/(hm²·a)，对照)、N2 (N，3 g/(hm²·a)，低氮)和N3 (N，6 g/(hm²·a)，高氮)3个处理，采用Biolog微平板法，分析了土壤微生物功能多样性在不同氮处理下的变化规律和特点。结果表明：不同氮沉降处理间土壤微生物功能多样性差异显著，AWCD值随培养时间延长而增加；Shannon和McIntosh多样性指数也随施氮增加呈现升高的趋势，且不同处理间多样性指数差异显著；物种多样性和功能多样性表现出相同的变化规律。土壤微生物对6大类碳源利用强度存在差异，各处理间土壤微生物对碳水化合物类碳源利用率最高，为优势碳源；主成分分析结果显示，不同处理间土壤微生物在碳源利用上有明显的空间分异，土壤微生物功能多样性的差异主要体现在对羧酸类、酚酸类和胺类碳源的利用上，其中胺类尤为突出；此外，对不同施氮处理土壤微生物群落功能多样性与土壤理化因子进行相关分析，结果显示全氮、铵态氮、全磷会对滨海湿地土壤微生物组成和功能活性产生重要影响。

In order to comprehensively understand the utilization characteristics of soil microbial carbon of native coastal wetlands, topsoil (0-20 cm) in native coastal wetlands were treated by three simulated nitrogen deposition levels and the characteristics and variation of microbial functional diversity were analyzed by Biolog microplate method. The results showed that there were significant differences in functional diversities of microbial communities under different treatments and AWCD increased with the extension of incubation time along; Shannon and Mcintosh diversity indexes increased first with nitrogen increasing, and the diversity indices were significantly different under different treatments; Species diversity and functional diversity showed the same variation. The utilization intensities of carbon sources of six categories had differences in which the carbohydrates were the most dominant carbon sources. Principal component analysis (PCA) identified that soil microbial carbon utilization had obvious spatial differentiation under different wetland types, horizontal zone difference of soil microbial functional diversity was reflected in the use of carbohydrates, amino acids and amine, and the amine was particularly prominent. In addition, the correlation analysis between microbial diversity and soil physiochemical properties showed that total nitrogen, nitrate nitrogen, total phosphorous had significant impacts on soil microbial composition and functional activity in native coastal wetlands.

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黑龙江省科学院青年创新基金 (STZ-201603)和江苏高校品牌专业建设工程项目(PPZY2015A081)资助。