Flexible Foliar Stoichiometry Reduces the Magnitude of the Global Land Carbon Sink
Flexible Foliar Stoichiometry Reduces the Magnitude of the Global Land Carbon Sink
复制标题
DOI：
10.1029/2023gl105493
复制
发表时间：
2023-11
影响因子：
5.2
通讯作者：
Emma Hauser;W. Wieder;G. Bonan;C. Cleveland
中科院分区：
文献类型：
--
作者：
Emma Hauser;W. Wieder;G. Bonan;C. Cleveland
在二氧化碳浓度升高的情况下，植物生长加快减缓了气候变暖的速度，并成为陆地碳(C)和气候动态预测的基础。然而，这一重要的生态系统服务可能会因植被碳氮比（C:N）的变化而减弱。尽管有明确的观测证据表明CO2升高会增加叶面C:N，但我们对叶面化学计量柔韧性的潜在生态后果的理解尚不完整。在这里，我们说明，当我们将二氧化碳驱动的叶面化学计量增加纳入群落土地模式时，与固定叶面化学模拟相比，到本世纪末预估的土地碳汇减少了两倍。此外，CO2驱动的叶面C:N的增加深刻地改变了地球的水文循环，减少了蒸散发和增加了径流，并降低了地下N循环速率。这些发现强调了进一步研究改变叶片化学计量对土壤氮循环和植物生产力的直接和间接影响的紧迫性。
Increased plant growth under elevated carbon dioxide (CO2) slows the pace of climate warming and underlies projections of terrestrial carbon (C) and climate dynamics. However, this important ecosystem service may be diminished by concurrent changes to vegetation carbon‐to‐nitrogen (C:N) ratios. Despite clear observational evidence of increasing foliar C:N under elevated CO2, our understanding of potential ecological consequences of foliar stoichiometric flexibility is incomplete. Here, we illustrate that when we incorporated CO2‐driven increases in foliar stoichiometry into the Community Land Model the projected land C sink decreased two‐fold by the end of the century compared to simulations with fixed foliar chemistry. Further, CO2‐driven increases in foliar C:N profoundly altered Earth's hydrologic cycle, reducing evapotranspiration and increasing runoff, and reduced belowground N cycling rates. These findings underscore the urgency of further research to examine both the direct and indirect effects of changing foliar stoichiometry on soil N cycling and plant productivity.