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摘要
Limited research has been conducted on how atmospheric carbon dioxide (CO2) affects water and soil nitrogen (N) transformation in wetland ecosystems. A stable isotope technique is suitable for conducting a detailed investigation of mechanistic nutrient transformations. Nutrient ammonium sulfate (NH4)(2)SO4 input in culture water under elevated CO2 (700 L L-1) and ambient CO2 (380 L L-1) was studied to analyze N transformations with N blanks for both water and soil. It was measured by N-15 pool dilution using analytical equations in a riparian wetland during a 3-month period. Soil gross ammonium (NH4 (+)) mineralization and consumption rates increased significantly by 22% and 404%, Whereas those of water decreased greatly by-57% and-57% respectively in enriched CO2. In contrast, gross nitrate (NO3 (-)) consumption and nitrification rates of soil decreased by-11% and-14% and those of water increased by 29% and 27% respectively in enrichment CO2. These may be due to the extremely high soil microbial biomass nitrogen (MBN), which increased by 94% in elevated soil. The results can show when CO2 concentrations are going to rise in the future. Consequently soil microbial activity initiates the decreased N concentration in sediment and increased N concentration in overlying water in riparian wetland ecosystems.
- 出版日期2013-7-20
- 单位河海大学
