Disentangling the Effects of Vapor Pressure Deficit and Soil Water Availability on Canopy Conductance in a Seasonal Tropical Forest During the 2015 El Niño Drought
Disentangling the Effects of Vapor Pressure Deficit and Soil Water Availability on Canopy Conductance in a Seasonal Tropical Forest During the 2015 El Niño Drought
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解开 2015 年厄尔尼诺干旱期间季节性热带森林中蒸气压不足和土壤水分可用性对冠层导度的影响
DOI：
10.1029/2021jd035004
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Gentine, Pierre
中科院分区：
文献类型：
--
作者：
Fang, Yilin;Leung, L. Ruby;Wolfe, Brett T;Detto, Matteo;Knox, Ryan G;McDowell, Nate G;Grossiord, Charlotte;Xu, Chonggang;Christoffersen, Bradley O;Gentine, Pierre
大气水分亏缺和土壤水分亏缺是制约蒸腾作用和植被生产力的两个关键因子。目前尚不清楚这两个因素中的哪一个对生态系统中的水和碳通量对干旱胁迫的响应更重要。在这项研究中，现场数据和数值模拟被用来隔离其对蒸散量（ET）和总初级生产力（GPP）的影响在热带森林网站在巴罗科罗拉多岛（BCI），巴拿马，重点是他们的响应引起的干旱厄尔尼诺事件的2015-2016年。利用植物水动力学方案（HYDRO）和启发式方法，忽略气孔对叶水势的敏感性，在能量Exascale地球系统模式（E3 SM）土地模式（ELM）进行数值模拟。从涡度相关通量和实测液流通量获得的冠层电导率（Gs）对水汽压亏缺（VPD）的敏感性表明，在厄尔尼诺事件期间，在生态系统和植物尺度上，土壤水分胁迫在BCI限制Gs比VPD更重要。模型模拟证实了水分胁迫对Gs的限制作用，但高估了VPD对Gs的影响。我们还发现，预测的土壤湿度是不敏感的植物水力性状的多样性比ET和GPP。在BCI的旱季期间，使用HYDRO和ELM模拟的季节性ET，特别是VPD > 0.42 kPa时的土壤蒸发太强，需要替代参数化。
Water deficit in the atmosphere and soil are two key interactive factors that constrain transpiration and vegetation productivity. It is not clear which of these two factors is more important for the water and carbon flux response to drought stress in ecosystems. In this study, field data and numerical modeling were used to isolate their impact on evapotranspiration (ET) and gross primary productivity (GPP) at a tropical forest site in Barro Colorado Island (BCI), Panama, focusing on their response to the drought induced by the El Niño event of 2015–2016. Numerical simulations were performed using a plant hydrodynamic scheme (HYDRO) and a heuristic approach that ignores stomatal sensitivity to leaf water potential in the Energy Exascale Earth System Model (E3SM) Land Model (ELM). The sensitivity of canopy conductance (Gs) to vapor pressure deficit (VPD) obtained from eddy‐covariance fluxes and measured sap flux shows that, at both ecosystem and plant scale, soil water stress is more important in limitingGsthan VPD at BCI during the El Niño event. The model simulations confirmed the importance of water stress limitation onGs, but overestimated the VPD impact onGscompared to that estimated from the observations. We also found that the predicted soil moisture is less sensitive to the diversity of plant hydraulic traits than ET and GPP. During the dry season at BCI, seasonal ET, especially soil evaporation at VPD > 0.42 kPa, simulated using HYDRO and ELM, were too strong and will require alternative parameterizations.
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影响因子：
4
作者：
K. Steppe
通讯作者：
K. Steppe
异速生长约束和竞争使得能够在热带森林动态植被模型（LM3PPA-TV）中模拟尺寸结构和碳通量
影响因子：
11.6
作者：
Isabel Martínez Cano;E. Shevliakova;S. Malyshev;S. J. Wright;M. Detto;S. Pacala;H. Muller‐Landau
通讯作者：
H. Muller‐Landau
影响因子：
1.8
作者：
R. Wirth;B. Weber;R. Ryel
通讯作者：
R. Ryel
DOI：
10.1017/cbo9780511840524.010
发表时间：
2019-01
期刊：
Wind Effects on Structures
影响因子：
--
作者：
John C. Wyngaard-
通讯作者：
John C. Wyngaard-
山艾树生态系统的恢复力和抵抗力与季节性土壤温度和可用水量有关
影响因子：
2.7
作者：
B. Roundy;J. Chambers;D. Pyke;Richard Miller;R. Tausch;E. Schupp;B. Rau;Trevor Gruell
通讯作者：
Trevor Gruell