PDF(Pubmed)
Abstract：
The apparent optimum air temperature for vegetation photosynthesis (Topt) is a key temperature parameter in terrestrial ecosystem models estimating daily photosynthesis or gross primary production (GPP, g C/m2/day). To date, most models use biome-specific Topt (Topt-biome) parameter values. Given vegetation acclimation and adaptation to local climate, site-specific Topt (Topt-site) is needed to reduce uncertainties in estimating daily GPP across the scales from site to region and the globe. Previous studies have demonstrated using the Enhanced Vegetation Index (EVI) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) images and daytime air temperature data to estimate the Topt-site at the eddy covariance tower sites. This study used MODIS-derived EVI and ERA5 climate data to estimate and generate global Topt-site data products from 2000 to 2019. The Topt-site of individual pixels within a biome has large variation, which clearly cannot be represented accurately by the widely used Topt-biome. Therefore, using this global dataset of Topt-site estimates might significantly affect GPP simulation in current ecosystem models.
摘要：
植被光合作用的表观最佳空气温度（Topt）是陆地生态系统模型中的关键温度参数，该模型估计每日光合作用或总初级生产（3GPP，gC/m2/天)。迄今为止,大多数模型使用生物群落特异性Topt(Topt-biome)参数值。考虑到植被适应和对当地气候的适应，需要针对特定地点的Topt（Topt-site），以减少在从地点到地区和全球范围内估计每日GP1的不确定性。先前的研究表明，使用中分辨率成像光谱辐射计（MODIS）图像和白天气温数据得出的增强植被指数（EVI）来估算涡流协方差塔站点的Topt站点。这项研究使用MODIS衍生的EVI和ERA5气候数据来估算和生成2000年至2019年的全球Topt站点数据产品。生物群落中单个像素的Topt位点有很大的变化，这显然不能用广泛使用的Topt生物群落来准确表示。因此,在当前的生态系统模型中，使用这个Topt站点估计的全球数据集可能会显着影响3GPP模拟。
