Immediate and adaptational temperature effects on nitric:: oxide production and nitrous oxide release from nitrification and denitrification in two soils
Immediate and adaptational temperature effects on nitric:: oxide production and nitrous oxide release from nitrification and denitrification in two soils
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DOI：
10.1007/s003740050584
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发表时间：
1999-11-01
影响因子：
6.5
通讯作者：
Conrad, R
中科院分区：
文献类型：
--
作者：
Gödde, M;Conrad, R
硝化作用和反硝化作用，像所有的生物过程一样，受温度的影响。研究了两种土壤在两种实验条件下，温度对硝化反硝化过程中氮素微量气体周转的影响。在第一种方法（"温度变化实验"）中，土壤样品在25摄氏度下预孵育，然后暴露于逐渐升高的温度（从4摄氏度开始，在40 - 45摄氏度结束）。在这些条件下，评估了温度变化的即时影响。在第二种方法（"离散温度实验"）中，土壤样品在不同温度（4 - 35摄氏度）下预培养5天，然后在相同温度下进行测试。不同的实验条件影响了研究结果。在变温实验中，两种土壤中NO的释放量均随温度的升高而稳定增加。然而，在离散温度实验中，NO和N2O的产生速率在中间温度（13 - 25 ℃）下显示出最小值。在其中一种土壤（土壤B9）中，在离散温度实验中硝化作用对NO产生的贡献百分比在25 ℃时达到最大值（> 95%的贡献）。在温变实验中，硝化作用始终是NO释放的主导过程，没有表现出系统的温度依赖性。在第二种土壤（土壤B14）中，随着温度从4 ℃升高到45 ℃，硝化作用对NO释放的贡献百分比从50%下降到10%，但在离散温度实验中没有明显差异。仅在离散温度实验中测量N2O产生速率。硝化作用对B9土壤N2O产生的贡献在25 - 35 ℃（60 - 80%的贡献）比在4 - 13 ℃（15 - 20%的贡献）高得多。在B14土壤中，4 ℃时硝化作用对N_2O产生的贡献最小。温度对N示踪气体周转的影响在两种土壤和培养条件之间存在差异。实验设置使我们能够区分短期温度变化对过程速率的直接影响，以及在特定温度下预孵育可能导致土壤微生物适应该温度的长期影响。这两种效应对土壤NO和N2O的释放都有重要的调控作用。
Nitrification and denitrification are, like all biological processes, influenced by temperature. We investigated temperature effects on N trace gas turnover by nitrification and denitrification in two soils under two experimental conditions. In the first approach ("temperature shift experiment") soil samples were preincubated at 25 degrees C and then exposed to gradually increasing temperatures (starting at 4 degrees C and finishing at 40-45 degrees C). Under these conditions the immediate effect of temperature change was assessed. In the second approach ("discrete temperature experiment") the soil samples were preincubated at different temperatures (4-35 degrees C) for 5 days and then tested at the same temperatures. The different experimental conditions affected the results of the study. In the temperature shift experiment the NO release increased steadily with increasing temperature in both soils. In the discrete temperature experiment, however, the production rates of NO and N2O showed a minimum at intermediate temperatures (13-25 degrees C). In one of the soils (soil B9), the percent contribution of nitrification to NO production in the discrete temperature experiment reached a maximum (>95% contribution) at 25 degrees C. In the temperature shift experiment nitrification was always the dominant process for NO release and showed no systematic temperature dependency. In the second soil (soil B14), the percent contribution of nitrification to NO release decreased from 50 to 10% as the temperature was increased from 4 degrees C to 45 degrees C, but no differences were evident in the discrete temperature experiment. The N2O production rates were measured in the discrete-temperature experiment only. The contribution of nitrification to N2O production in soil B9 was considerably higher at 25-35 degrees C (60-80% contribution) than at 4-13 degrees C (15-20% contribution). In soil B14 the contribution of nitrification to N2O production was lowest at 4 degrees C. The effects of temperature on N trace gas turnover differed between the two soils and incubation conditions. The experimental set-up allowed us to distinguish between immediate effects of short-term changes in temperature on the process rates, and longer-term effects by which preincubation at a particular temperature presumably resulted in the adaptation of the soil microorganisms to this temperature. Both types of effects were important in regulating the release of NO and N2O from soil.