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在淡水湖泊生态系统中,水位高程的变化会对整个生态系统产生重要的影响。本研究以鄱阳湖最具代表性的碟形湖——蚌湖为实验地点,研究了水位高程对于湖泊湿地土壤微生物代谢功能的影响。在实验中沿水位高程及植被带演替布设6个样地,利用Biolog-Eco技术探究不同水位高程样地土壤微生物群落代谢功能的多样性及分布规律。结果表明:随着样地水位高程的降低,土壤含水量逐渐升高,地表植被的覆盖率逐渐减少,土壤有机养分出现先减小后增大的趋势;而土壤微生物对碳源代谢活性随着高程的降低依次减弱,且优先利用的碳源种类和碳源利用率也有显著不同。通过dbRDA排序分析表明:土壤微生物群落功能多样性沿高程呈现区域性分布特征,相邻的两样地土壤微生物碳源代谢功能更为相近。影响湿地土壤微生物碳源代谢功能的主要因子为土壤含水量、土壤有机质含量、pH、NH_4-N和地表植被类型。本研究结果可为合理管理和保护鄱阳湖湿地生态系统提供科学的指导。
In freshwater lake ecosystems, changes in water level elevation can have a significant impact on the entire ecosystem. In this study, the most representative lake in Poyang Lake - Lake Bang Lake as experimental sites, studied the effect of water level elevation on soil microbial metabolic function in lake wetlands. In the experiment, six plots were set up along the elevation of water level and the succession of vegetation belt. Biolog-Eco technique was used to explore the diversity and distribution of metabolic function of soil microbial community at different water level elevations. The results showed that with the elevation of water level decreased, the soil water content gradually increased, the coverage of surface vegetation decreased gradually, and the soil organic nutrient decreased at first and then increased. However, In turn, the reduction of elevation is weakened, and the types of carbon sources and carbon utilization that are prioritized are also significantly different. By dbRDA ranking analysis showed that: functional diversity of soil microbial communities along the elevation showing the regional distribution characteristics, adjacent to the two soil microbial carbon metabolism is more similar. The main factors influencing the metabolic function of soil microbial carbon sources in wetlands were soil water content, soil organic matter content, pH, NH_4-N and surface vegetation types. The results of this study can provide scientific guidance for the rational management and protection of the Poyang Lake wetland ecosystem.