National Ecosystem Science Data Center, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi, China.
National Ecosystem Science Data Center, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
Sci Total Environ. 2022 Apr 20;818:151719. doi: 10.1016/j.scitotenv.2021.151719. Epub 2021 Nov 22.
Tropical vegetation respiration (TVR) is affected by extreme climate change. As it is very difficult to directly observe TVR, our understanding of the land-ocean-atmosphere carbon cycle, and particularly the regulatory effect of El Niño-Southern Oscillation (ENSO) on TVR and the land-atmosphere carbon balance, is very limited. Therefore, usingModerate Resolution Imaging Spectroradiometer (MODIS) products and meteorological data, we investigated the response of TVR to changes in ENSO during 2000-2015. The influence of El Niño on TVR was approximately 10.8% higher than that of La Niña. During El Niño years, a significant and anomalous increase in thermal measures related to TVR and ENSO and a significant and anomalous decrease in related hydrological measures favor the formation of warmer and drier climate conditions. Furthermore, the zonal distributions of air temperature and vertical velocity at 200-1000 hPa during El Niño years show that a stronger atmospheric inversion over tropical regions causes an increase in the surface temperature. Moreover, anomalous atmospheric subsidence inhibits the upward transport of water vapor, leading to a decrease in the cloud formation probability and reduced precipitation. In summary, increased surface temperatures caused by increased solar radiation and enhanced atmospheric inversion and decreased precipitation cause warmer and drier climate conditions, which forces TVR to increase. As TVR constitutes the key node of the land-atmosphere‑carbon cycle process, we focus on TVR and its close linkage with ENSO events and further establish a knowledge framework for understanding the land-atmosphere-ocean carbon cycle. This study deepens our understanding of not only the mechanism of the land-atmosphere carbon balance but also the ocean-induced terrestrial ecosystem processes spurred by ENSO-involved climate change. PLAIN LANGUAGE SUMMARY: Vegetation respiration regulates the carbon balance of the land and atmosphere. As it is very difficult to directly observe vegetation respiration, our understanding of the land-ocean-atmosphere carbon cycle involved and the roles of vegetation respiration and El Niño-Southern Oscillation (ENSO) in regulating the land-atmosphere carbon balance is very limited. Therefore, using MODIS products and meteorological data, we investigated the response of tropical vegetation respiration to changes in ENSO during 2000-2015. We found that during El Niño years, warmer and drier climate conditions over tropical regions increased vegetation respiration. Exacerbating the warmer and drier climate conditions, upper atmospheric warm anomalies further caused a remarkable increase in tropical vegetation respiration. Based on the land-atmosphere‑carbon cycle process, we establish a knowledge framework for understanding the land-atmosphere-ocean carbon cycle. This knowledge deepens our understanding of not only the mechanism of the land-atmosphere carbon balance but also the ocean-induced terrestrial ecosystem processes spurred by ENSO-involved climate change.
热带植被呼吸（TVR）受极端气候变化的影响。由于很难直接观测 TVR，我们对陆地-海洋-大气碳循环的理解，特别是厄尔尼诺-南方涛动（ENSO）对 TVR 和陆地-大气碳平衡的调节作用非常有限。因此，本研究利用中分辨率成像光谱仪（MODIS）产品和气象数据，调查了 2000-2015 年 ENSO 变化对 TVR 的响应。厄尔尼诺对 TVR 的影响比拉尼娜高出约 10.8%。在厄尔尼诺年，与 TVR 和 ENSO 相关的热测量值会出现显著且异常的增加，与相关水文测量值相关的湿度会出现显著且异常的降低，有利于形成更温暖和干燥的气候条件。此外，厄尔尼诺年热带地区 200-1000 hPa 高度的气温和垂直速度的纬向分布表明，热带地区更强的大气逆温导致地表温度升高。此外，异常的大气下沉抑制了水汽的向上输送，导致云形成概率降低和降水减少。总之，太阳辐射增加、大气逆温增强和降水减少导致的地表温度升高导致更温暖和干燥的气候条件，从而迫使 TVR 增加。由于 TVR 构成陆地-大气-碳循环过程的关键节点，我们专注于 TVR 及其与 ENSO 事件的密切联系，并进一步建立一个理解陆地-大气-海洋碳循环的知识框架。本研究不仅加深了我们对陆地-大气碳平衡机制的理解，还加深了我们对 ENSO 相关气候变化引起的海洋驱动陆地生态系统过程的理解。
