Suppression of methane uptake by precipitation pulses and long-term nitrogen addition in a semi-arid meadow steppe in northeast China.
Suppression of methane uptake by precipitation pulses and long-term nitrogen addition in a semi-arid meadow steppe in northeast China.
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中国东北半干旱草甸草原降水脉冲和长期氮添加对甲烷吸收的抑制
DOI：
10.3389/fpls.2022.1071511
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发表时间：
2022
影响因子：
5.6
通讯作者：
Sun, Wei
中科院分区：
文献类型：
--
作者：
Gao, Weifeng;Yang, Xu;Zhang, Yicong;Zhao, Tianhang;Shi, Baoku;Yang, Tianxue;Ma, Jianying;Xu, Wanling;Wu, Yining;Sun, Wei
在全球变化的背景下，降水脉冲频率预计会减少，而氮(N)添加量预计会增加，这将对土壤C循环过程和甲烷（CH4）通量产生关键影响。然而，降水脉冲和N添加对草地生态系统CH4通量的交互作用在很大程度上仍然未知。本研究通过模拟一系列降水脉冲（0、5、10、20和50 mm）和长期N添加量（0和10 g N m-2年-1年、10年）对半干旱草地CH4通量的影响。结果表明：大降水脉冲（10 mm、20 mm和50 mm）对CH4通量具有负脉冲效应，与0 mm降水脉冲相比，CH4通量峰值相对降低了203 ~ 362%；大降水脉冲显著抑制CH4吸收，使累积CH4通量降低68 ~ 88%，而小降水脉冲（5 mm）对CH4吸收无显著影响。我们首次发现，在对照和N添加处理中，降水脉冲大小均以二次曲线方式增加累积CH4通量。降水脉冲引起的土壤水分增加通过抑制CH4吸收和促进CH4释放来抑制CH4的吸收。添加氮肥通过增加NH4 +-N和NO3——N含量显著降低CH4的吸收，通过增加地上生物量增加CH4的产量，最终抑制CH4的吸收。令人惊讶的是，降水脉冲和N添加没有相互作用影响CH4吸收，因为降水脉冲和N添加对pH有抵消作用，并通过不同的途径影响CH4通量。综上所述，降水脉冲和N添加抑制了土壤对大气中CH4的吸收，降低了草地生态系统的CH4汇容量。
In the context of global change, the frequency of precipitation pulses is expected to decrease while nitrogen (N) addition is expected to increase, which will have a crucial effect on soil C cycling processes as well as methane (CH4) fluxes. The interactive effects of precipitation pulses and N addition on ecosystem CH4 fluxes, however, remain largely unknown in grassland. In this study, a series of precipitation pulses (0, 5, 10, 20, and 50 mm) and long-term N addition (0 and 10 g N m-2 yr-1, 10 years) was simulated to investigate their effects on CH4 fluxes in a semi-arid grassland. The results showed that large precipitation pulses (10 mm, 20 mm, and 50 mm) had a negative pulsing effect on CH4 fluxes and relatively decreased the peak CH4 fluxes by 203-362% compared with 0 mm precipitation pulse. The large precipitation pulses significantly inhibited CH4 absorption and decreased the cumulative CH4 fluxes by 68-88%, but small precipitation pulses (5 mm) did not significantly alter it. For the first time, we found that precipitation pulse size increased cumulative CH4 fluxes quadratically in both control and N addition treatments. The increased soil moisture caused by precipitation pulses inhibited CH4 absorption by suppressing CH4 uptake and promoting CH4 release. Nitrogen addition significantly decreased the absorption of CH4 by increasing NH4 +-N content and NO3 –-N content and increased the production of CH4 by increasing aboveground biomass, ultimately suppressing CH4 uptake. Surprisingly, precipitation pulses and N addition did not interact to affect CH4 uptake because precipitation pulses and N addition had an offset effect on pH and affected CH4 fluxes through different pathways. In summary, precipitation pulses and N addition were able to suppress the absorption of CH4 from the atmosphere by soil, reducing the CH4 sink capacity of grassland ecosystems.
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影响因子：
9.7
作者：
Borken, W;Davidson, EA;Steudler, P
通讯作者：
Steudler, P
影响因子：
6.1
作者：
Chen, Weiwei;Zheng, Xunhua;Lin, Shan
通讯作者：
Lin, Shan
影响因子：
6.6
作者：
Decock, Charlotte;Six, Johan
通讯作者：
Six, Johan
低水平氮沉降显着抑制青藏高原高寒草甸土壤甲烷吸收
影响因子：
6.1
作者：
Fang, Huajun;Cheng, Shulan;Li, Yingnian
通讯作者：
Li, Yingnian
影响因子：
11.6
作者：
Deng, Lei;Huang, Chunbo;Peng, Changhui
通讯作者：
Peng, Changhui