The effect of plant physiological responses to rising CO2 on global streamflow
The effect of plant physiological responses to rising CO2 on global streamflow
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DOI：
10.1038/s41558-019-0602-x
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发表时间：
2019-11-01
影响因子：
30.7
通讯作者：
Pritchard, Michael S.
中科院分区：
文献类型：
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作者：
Fowler, Megan D.;Kooperman, Gabriel J.;Pritchard, Michael S.
由于大气中二氧化碳含量的增加，河流流量统计数据预计会发生变化，但地球系统模型预测的不确定性很高。虽然这在一定程度上是由降水变化驱动的，但众所周知，地球系统模型存在不确定性，但我们在这里表明，植物气孔导度反馈的影响可能会导致区域洪水极端事件发生同样大的变化，甚至成为未来低纬度水流的主要控制因素。现代气候预测表明，在大多数热带陆地上，植物的生理效应将促进水流的增加，压倒二氧化碳对大气辐射、变暖和降雨重新分配造成的土壤干燥的相反影响。因此，必须在地表模型中更好地限制代表生态生理过程的相对未知的不确定性。为此，我们确定了整个热带地区年峰值、低值和平均排放量的独特植物生理指纹，并确定了在现代气候预测中生理反应主导对二氧化碳上升的辐射反应的河流流域。
River flow statistics are expected to change as a result of increasing atmospheric CO2 but uncertainty in Earth system model projections is high. While this is partly driven by changing precipitation, with well-known Earth system model uncertainties, here we show that the influence of plant stomatal conductance feedbacks can cause equally large changes in regional flood extremes and even act as the main control on future low latitude streamflow. Over most tropical land masses, modern climate predictions suggest that plant physiological effects will boost streamflow, overwhelming opposing effects of soil drying driven by the effects of CO2 on atmospheric radiation, warming and rainfall redistribution. The relatively unknown uncertainties in representing eco-physiological processes must therefore be better constrained in land-surface models. To this end, we identify a distinct plant physiological fingerprint on annual peak, low and mean discharge throughout the tropics and identify river basins where physiological responses dominate radiative responses to rising CO2 in modern climate projections.