Data from: Gross primary productivity from leaf-age-dependent light use efficiency (LA-LUE) model over pantropical evergreen broadleaved forests

Tropical and subtropical evergreen broadleaved forests (TEFs) contribute
more than one-third of terrestrial gross primary productivity (GPP).
However, the continental-scale leaf phenology-photosynthesis nexus over
TEFs is still poorly understood to date. This knowledge gap hinders most
light use efficiency (LUE) models from accurately simulating the GPP
seasonality in TEFs. Leaf age is the crucial plant trait to link the
dynamics of leaf phenology with GPP seasonality. Thus, here we
incorporated the seasonal leaf area index (LAI) of different leaf age
cohorts into a widely-used LUE model (i.e., EC-LUE) and proposed a novel
leaf-age-dependent LUE model (denoted as LA-LUE model). At the site level,
the LA-LUE model (average R2 = 0.59, average RMSE = 1.23 gC m−2 d−1)
performs better than the EC-LUE model in simulating the GPP seasonality
across the nine TEFs sites (average R2 = 0.18; average RMSE = 1.87 gC m-2
d-1). At the continental scale, the monthly GPP estimates from the LA-LUE
model are consistent with FLUXCOM GPP data (R2 = 0.80; average RMSE = 1.74
gC m-2 d-1), and satellite-based GPP data retrieved from the global
Orbiting Carbon Observatory-2 (OCO-2) based solar-induced chlorophyll
fluorescence (SIF) product (GOSIF) (R2 = 0.64; average RMSE = 1.90 gC m-2
d-1) and the reconstructed TROPOspheric Monitoring Instrument SIF dataset
using machine learning algorithms (RTSIF) (R2 = 0.78; average RMSE = 1.88
gC m-2 d-1). Typically, the estimated monthly GPP not only successfully
represents the unimodal GPP seasonality near the Tropics of Cancer and
Capricorn, but also captures well the bimodal GPP seasonality near the
Equator. Overall, this study for the first time integrates the leaf age
information into the satellite-based LUE model and provides a feasible
implementation for mapping the continental-scale GPP seasonality over the
entire TEFs.