Interactions among climate, topography and herbivory control greenhouse gas (CO2, CH4 and N2O) fluxes in a subarctic coastal wetland
Interactions among climate, topography and herbivory control greenhouse gas (CO2, CH4 and N2O) fluxes in a subarctic coastal wetland
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亚北极沿海湿地气候、地形和食草动物控制温室气体（CO2、CH4 和 N2O）通量之间的相互作用
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
J. Welker
中科院分区：
文献类型：
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作者：
K. Kelsey;A. Lef;Er;K. Beard;J. Schmutz;R. Choi;J. Welker
高纬度生态系统正在经历全球最快的气候变化，在许多地区，这些变化与草食模式的转变同时发生。就个体而言，气候和草食已知影响生物圈-大气温室气体(GHG)交换；然而，气候和草食在驱动温室气体通量方面的交互影响的量化很差，特别是在支持大量迁徙水禽的沿海系统中。我们研究了阿拉斯加西部育空-库斯科维姆三角洲内由草食和当地微地形形成的四个不同的植被群落中温室气体交换的规模及其气候和物理控制。CO2净通量以未放牧的苔草群落最大(3.97±0.58[SE]μmolCO2m2 S)，而CH4通量以放牧群落最大(14.00±6.56nmolCH4m2 S)。放牧群落也是唯一一种CH4对整个温室气体强迫的贡献大于CO2的植被类型。我们发现，植被群落是CO2和CH4交换的重要预测因子，这表明当考虑放牧的影响时，区域气体交换的变化可以得到最好的解释，放牧和非放牧群落的差异决定了放牧的影响。此外，我们确定了温度和植被群落之间的相互作用，表明随着气候变暖，放牧地区的CH4排放可能会经历最大的增加。这些结果表明，未来的温室气体通量可能受到气候和草食动物种群动态变化的影响，草食动物种群动态的变化对未来温度变化的反应最快。
High-latitude ecosystems are experiencing the most rapid climate changes globally, and in many areas these changes are concurrent with shifts in patterns of herbivory. Individually, climate and herbivory are known to influence biosphere-atmosphere greenhouse gas (GHG) exchange; however, the interactive effects of climate and herbivory in driving GHG fluxes have been poorly quantified, especially in coastal systems that support large populations of migratory waterfowl. We investigated the magnitude and the climatic and physical controls of GHG exchange within the Yukon-Kuskokwim Delta in western Alaska across four distinct vegetation communities formed by herbivory and local microtopography. Net CO2 flux was greatest in the ungrazed Carex meadow community (3.97 0.58 [SE]μmol CO2m 2 s ), but CH4 flux was greatest in the grazed community (14.00 6.56 nmol CH4m 2 s ). The grazed community is also the only vegetation type where CH4 was a larger contributor than CO2 to overall GHG forcing. We found that vegetation community was an important predictor of CO2 and CH4 exchange, demonstrating that variation in regional gas exchange is best explained when the effect of grazing, determined by the difference between grazed and ungrazed communities, is included. Further, we identified an interaction between temperature and vegetation community, indicating that grazed regions could experience the greatest increases in CH4 emissions with warming. These results suggest that future GHG fluxes could be influenced by both climate and by changes in herbivore population dynamics that expand or contract the vegetation community most responsive to future temperature change.
影响因子：
11.6
作者：
M. Turetsky;A. Kotowska;J. Bubier;N. Dise;P. Crill;E. Hornibrook;K. Minkkinen;T. Moore;I. Myers-Smith
通讯作者：
M. Turetsky;A. Kotowska;J. Bubier;N. Dise;P. Crill;E. Hornibrook;K. Minkkinen;T. Moore;I. Myers-Smith
影响因子：
6.6
作者：
Nakagawa, Shinichi;Schielzeth, Holger
通讯作者：
Schielzeth, Holger