International Institute for Earth System Science, Nanjing University, Nanjing 210023, China; School of Geography Science and Tourism, Xinjiang Normal University, Urumqi 830054, China.
School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China; Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing 210023, China.
Sci Total Environ. 2018 Feb 1;613-614:977-989. doi: 10.1016/j.scitotenv.2017.09.002. Epub 2017 Sep 26.
Estimating terrestrial gross primary production is an important task when studying the carbon cycle. In this study, the ability of a two-leaf light use efficiency model to simulate regional gross primary production in China was validated using satellite Global Ozone Monitoring Instrument - 2 sun-induced chlorophyll fluorescence data. The two-leaf light use efficiency model was used to estimate daily gross primary production in China's terrestrial ecosystems with 500-m resolution for the period from 2007 to 2014. Gross primary production simulated with the two-leaf light use efficiency model was resampled to a spatial resolution of 0.5° and then compared with sun-induced chlorophyll fluorescence. During the study period, sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model exhibited similar spatial and temporal patterns in China. The correlation coefficient between sun-induced chlorophyll fluorescence and monthly gross primary production simulated by the two-leaf light use efficiency model was significant (p<0.05, n=96) in 88.9% of vegetated areas in China (average value 0.78) and varied among vegetation types. The interannual variations in monthly sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model were similar in spring and autumn in most vegetated regions, but dissimilar in winter and summer. The spatial variability of sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model was similar in spring, summer, and autumn. The proportion of spatial variations of sun-induced chlorophyll fluorescence and annual gross primary production simulated by the two-leaf light use efficiency model explained by ranged from 0.76 (2011) to 0.80 (2013) during the study period. Overall, the two-leaf light use efficiency model was capable of capturing spatial and temporal variations in gross primary production in China. However, the model needs further improvement to better simulate gross primary production in summer.
估算陆地总初级生产力是研究碳循环的一项重要任务。本研究利用卫星全球臭氧监测仪器-2 太阳诱导叶绿素荧光数据验证了两叶光能利用效率模型模拟中国区域总初级生产力的能力。利用两叶光能利用效率模型，以 500m 分辨率估算了 2007 年至 2014 年中国陆地生态系统的日总初级生产力。将两叶光能利用效率模型模拟的总初级生产力重采样到 0.5°的空间分辨率，并与太阳诱导叶绿素荧光进行比较。在研究期间，中国的太阳诱导叶绿素荧光和两叶光能利用效率模型模拟的总初级生产力表现出相似的时空模式。在中国，太阳诱导叶绿素荧光与两叶光能利用效率模型模拟的月总初级生产力之间的相关系数在 88.9%的植被区显著（p<0.05，n=96）（平均值为 0.78），且在不同植被类型之间存在差异。在中国大多数植被区，两叶光能利用效率模型模拟的月太阳诱导叶绿素荧光和总初级生产力的年际变化在春季和秋季相似，但在冬季和夏季不同。两叶光能利用效率模型模拟的太阳诱导叶绿素荧光和总初级生产力的空间变异性在春季、夏季和秋季相似。两叶光能利用效率模型模拟的太阳诱导叶绿素荧光和年总初级生产力的空间变化比例在研究期间的解释范围为 0.76（2011 年）至 0.80（2013 年）。总体而言，两叶光能利用效率模型能够捕捉中国总初级生产力的时空变化。然而，该模型需要进一步改进，以更好地模拟夏季的总初级生产力。
