Light-use efficiency (LUE), which quantifies the plants' efficiency in utilizing solar radiation for photosynthetic carbon fixation, is an important factor for gross primary production estimation. Here we use satellite-based solar-induced chlorophyll fluorescence as a proxy for photosynthetically active radiation absorbed by chlorophyll (APAR chl ) and derive an estimation of the fraction of APAR chl (fPAR chl ) from four remotely sensed vegetation indicators. By comparing maximum LUE estimated at different scales from 127 eddy flux sites, we found that the maximum daily LUE based on PAR absorption by canopy chlorophyll ( εmaxchl), unlike other expressions of LUE, tends to converge across biome types. The photosynthetic seasonality in tropical forests can also be tracked by the change of fPAR chl , suggesting the corresponding εmaxchl to have less seasonal variation. This spatio-temporal convergence of LUE derived from fPAR chl can be used to build simple but robust gross primary production models and to better constrain process-based models.
- fraction of absorbed photosynthetic active radiation
- gross primary productivity
- optical vegetation activity indicator
- photosynthetic capacity
- production efficiency models
- solar-induced chlorophyll fluorescence