Nonlinear responses of soil respiration to precipitation changes in a semiarid temperate steppe.
Nonlinear responses of soil respiration to precipitation changes in a semiarid temperate steppe.
复制标题
半干旱温带草原土壤呼吸对降水变化的非线性响应
DOI：
10.1038/srep45782
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发表时间：
2017-03-31
影响因子：
4.6
通讯作者：
Wan S
中科院分区：
文献类型：
--
作者：
Miao Y;Han H;Du Y;Zhang Q;Jiang L;Hui D;Wan S
未来极端降水事件的发生频率将会增加，并将对陆地生态系统碳(C)循环产生重大影响。然而，在陆地生态系统中，土壤呼吸对降水变化的响应模式仍然不确定。在中国北方半干旱温带草原的3个生长季节（2010-2012年）进行了7种降水处理（即从环境降水的- 60%到+60%形成干旱到潮湿的降水梯度）的田间试验。结果表明，土壤呼吸沿试验降水梯度呈非线性响应模式，随降水减少而抑制，随降水增加而增强。在3个生长季节中，3个干旱处理的土壤呼吸减少幅度（−60、−40和−20%处理分别减少45.8%、32.8和15.9%）大于3个湿处理（+20、+40和+60%处理分别减少8.9、14.3和18.5%）。结果表明，土壤呼吸对降水减少处理比降水增加处理更敏感。土壤呼吸对降水变化的非线性和非对称响应应纳入生态系统模型，以预测与气候变化相关的生态系统碳循环。
Extreme precipitation events are predicted to occur more frequently and will have significant influences on terrestrial ecosystem carbon (C) cycling in the future. However, response patterns of soil respiration to precipitation changes remain uncertain in terrestrial ecosystems. A field experiment with seven precipitation treatments (i.e. from −60% to +60% of ambient precipitation to form a drought to wet precipitation gradient) was conducted over three growing seasons (2010–2012) in a semiarid temperate steppe of Northern China. Results showed a nonlinear response pattern of soil respiration along the experimental precipitation gradient, with soil respiration suppressed by decreased precipitation and enhanced by increased precipitation. Over the three growing seasons, soil respiration was reduced more under the three drought treatments (by 45.8, 32.8, and 15.9% under the −60, −40, and −20% treatments, respectively) than stimulated under the three wet treatments (by 8.9, 14.3, and 18.5% under the +20, +40, and +60% treatments, respectively). Our results indicate that soil respiration was more sensitive to decreased than increased precipitation treatments. The nonlinear and asymmetric responses of soil respiration to precipitation changes should be built into ecosystem models to project ecosystem C cycling associated with climate change.