【摘要】 为了研究不同土地利用方式对碳、氮动态的影响,在中国科学院三江平原湿地生态试验站综合试验场对3种不同土地利用类型的地上生物量和碳、氮库的动态变化进行了研究。结果表明:地上生物量,地上碳、氮库,土壤碳、氮库分别递增顺序为耕地<弃耕地<沼泽化草甸。湿地开垦7年后,地上生物量下降了69.25％,土壤有机碳库减少了47％,土壤氮库减少了50.91％;而弃耕5年后,地上生物量恢复到原始水平的71.61％,土壤碳、氮库分别达到沼泽化草甸的62.6％和50.32％;无机氮（0～25cm）的动态与土壤全氮相似,其变化规律为耕地<弃耕地<沼泽化草甸,但是NO₃^--N/（NH₄⁺-N+NO₃^--N）的比值却与此正好相反,呈沼泽化草甸<弃耕地<耕地的趋势。说明在沼泽化草甸土壤中氮的可利用性最高,其次是弃耕地,耕地最低。更多还原

【Abstract】 We selected three types of soils to estimate the dynamics of carbon and nitrogen under different land-use conditions in the experimental fields of the Ecological Experimental Station of Mire-wetlands in the Sanjiang Plain. The results show that the dynamics of total aboveground biomass, aboveground carbon and nitrogen pools, carbon and nitrogen pools in soils are similar, cultivation < abandonment < marsh meadow. Total aboveground biomass decreases by 69.25 %, pools of carbon and nitrogen in soils decrease by 47% and 50.91% respectively, after being cultivated for 7 years. However, after abandonment for 5 years, total aboveground biomass reaches 71.61 % of the initial level, pools of carbon and nitrogen in soils restore to 62.6% and 50.32% of the meadow-boggy soil respectively. Dynamics of inorganic nitrogen in soils are similar to the pools of nitrogen, cultivation <abandonment <marsh meadow. Contrary to inorganic nitrogen, the ratio of NO₃^- -N/（NH⁴-N+ NO₃^- -N） is opposite, cultivation > abandonment > marsh meadow, showing that the availability of nitrogen is the highest in the Mire-wetlands and the lowest in the cultivation.更多还原