Related Experiment Video
Updated: Jun 21, 2025

Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites
Published on: June 24, 2019
Site-specific apparent optimum air temperature for vegetation photosynthesis across the globe
Li Pan1, Xiangming Xiao2, Yuan Yao1
1School of Biological Sciences, Center for Earth Observation and Modeling, University of Oklahoma, Norman, OK, 73019, USA.
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.
Related Concept Videos
Responses to Heat and Cold Stress
Adaptations that Reduce Water Loss
Light Acquisition
Radiation: Applications
The average...
The Antenna Complex
Biological Clocks and Seasonal Responses

