Different types of nitrogen deposition show variable effects on the soil carbon cycle process of temperate forests
Different types of nitrogen deposition show variable effects on the soil carbon cycle process of temperate forests
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DOI：
10.1111/gcb.12555
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发表时间：
2014-10-01
影响因子：
11.6
通讯作者：
Jiao, Zhenxia
中科院分区：
文献类型：
--
作者：
Du, Yuhan;Guo, Peng;Jiao, Zhenxia
氮（N）沉降显着影响森林土壤碳（C）循环过程。但不同类型N对其的影响仍不清楚。在这项工作中，选择硝酸铵作为无机 N (IN) 源，而选择尿素和甘氨酸作为有机 N (ON) 源。将不同比例的IN与ON（1:4、2:3、3:2、4:1和5:0）等量混合，然后用于温带森林土壤施肥2年。结果表明，IN沉积抑制了土壤碳循环过程，如土壤呼吸、土壤有机碳分解和酶活性，并诱导顽固有机碳的积累。相反，ON沉积促进了这些过程。添加 ON 还导致顽固化合物加速转化为不稳定化合物，并增加 CO2 流出。同时，更多的ON沉降可能会将森林土壤中的碳固存转化为碳源。这些结果表明IN与ON的比例在控制土壤碳循环中的重要性，从而改变氮沉降的生态效应。
Nitrogen (N) deposition significantly affects the soil carbon (C) cycle process of forests. However, the influence of different types of N on it still remained unclear. In this work, ammonium nitrate was selected as an inorganic N (IN) source, while urea and glycine were chosen as organic N (ON) sources. Different ratios of IN to ON (1:4, 2:3, 3:2, 4:1, and 5:0) were mixed with equal total amounts and then used to fertilize temperate forest soils for 2years. Results showed that IN deposition inhibited soil C cycle processes, such as soil respiration, soil organic C decomposition, and enzymatic activities, and induced the accumulation of recalcitrant organic C. By contrast, ON deposition promoted these processes. Addition of ON also resulted in accelerated transformation of recalcitrant compounds into labile compounds and increased CO2 efflux. Meanwhile, greater ON deposition may convert C sequestration in forest soils into C source. These results indicated the importance of the IN to ON ratio in controlling the soil C cycle, which can consequently change the ecological effect of N deposition.