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作 者 ：孙志高^1,2;刘景双¹;杨继松^1,2;李新华^1,2;周旺明^1,2

期 刊 ：应用生态学报 2007年 18卷 01期 页码：185-192

关键词：小叶章；

摘 要 ：应用C₂H₂抑制原状土柱培育法研究了三江平原典型小叶章湿地土壤N₂O排放速率及反硝化速率的变化，分析了它们与环境因子的关系，并估算了N₂O排放量及反硝化损失量.结果表明：草甸沼泽土和腐殖质沼泽土N₂O排放速率的变化基本一致，其范围分别为0.020～0.089 kg N·hm^-2·d^-1和0.012～0.033 kg N·hm^-2·d^-1,前者的N₂O排放速率均明显高于后者(平均为1.79±1.07倍)，且其差异达到显著水平(P＜0.05)；二者反硝化速率的变化并不一致，其范围分别为0.024～0.127 kg N·hm^-2·d^-1和0.021～0.043 kg N·hm^-2·d^-1，前者的反硝化速率一般也要高于后者(平均为1.67±1.56倍)，但其差异并未达到显著水平(P＞0.05)；硝化作用在前者N₂O排放和氮素损失过程中发挥了重要作用，而反硝化作用则是导致后者N₂O排放和氮素损失的重要过程；氮素物质基础不是影响二者硝化-反硝化作用的重要因素；温度对前者硝化反硝化作用的影响比后者更为明显，其反硝化速率与5、10和15 cm地温均呈显著正相关(P＜0.05)；二者所处湿地水分条件的差异是导致其N₂O排放速率及反硝化速率差异的重要原因.生长季内，前者的N₂O排放量和反硝化损失量分别为5.216 kg N·hm^-2和6.166 kg N·hm^-2，而后者分别为3.196 kg N·hm^-2和4.407 kg N·hm^-2；在二者的反硝化产物中，N₂O/N₂的比率最高，分别为5.49和3.76，表明N₂在后者反硝化产物中所占的比例明显高于前者，说明季节积水条件会导致N₂O/N₂比例降低.

Abstract:With intact soil core and by using acetylene inhibition method, this paper measured the
N₂O emission and denitrification rates of typical Calamagrostis angustifolia wetland soils in Sanjiang
Plain, analyzed their relationships with environmental factors, and estimated the total amounts of
N₂O emission and denitrification loss. The results showed that meadow marsh soil and humus marsh
soil had a similar change range of N₂O emission rate (0.020-0.089 kg N·hm²·d^-1 and 0.012
-0.033 kg N·hm²·d^-1, respectively), but the former had a much higher N₂O emission rate
than the latter, and the difference was significant (P＜0.05). As for denitrification rate, its
change range was 0.024-0.127 kg N·hm²·d^-1 for meadow marsh soil and 0.021-0.043 kg N
·hm²·d^-1 for humus marsh soil. Meadow marsh soil also had a higher denitrification rate than
humus marsh soil, but the difference was not significant (P＞0.05). In meadow marsh soil,
nitrification played an important role in N₂O emission and nitrogen loss; while in humus marsh soil,
denitrification was the main process inducing N₂O emission and nitrogen loss. For these two soils,
nitrogenous compounds were not the important factor affecting nitrification-denitrification. In
meadow marsh soil, temperature had more evident effect, where nitrification-denitrification had a
significant positive correlation with the soil temperature at the depths of 5 cm, 10 cm and 15 cm (P＜
0.05). Soil moisture condition was another important factor inducing the difference of N₂O emission
and denitrification rates. In growth season, the amount of N₂O emission and denitrification loss was
5.216 kg N·hm^-2 and 6.166 kg N·hm^-2 for meadow marsh soil, and 3.196 kg N·hm^-2 and
4.407 kg N·hm^-2 for humus marsh soil, respectively. In the denitrification productions of meadow
marsh soil and humus marsh soil, the maximum value of N₂O/N₂ ratio was 5.49 and 3.76,
respectively, indicating that the proportion of N₂ in denitrification productions was higher in humus
marsh soil than in meadow marsh soil, and the seasonal waterlogged condition could induce the
decrease of N₂O/N₂ ratio.

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