Abstract
Twelve global net primary productivity (NPP) models were compared: BIOME3, CASA, CARAIB, FBM, GLO-PEM, HYBRID, KGBM, PLAI, SDBM, SIB2, SILVAN and TURC. These models all use solar radiation as an input, and compute either absorbed solar radiation directly, or the amount of leaves used to absorb solar radiation, represented by the leaf area index (LAI). For all models, we obtained or estimated photosynthetically active radiation absorbed by the canopy (APAR). We then computed the light use efficiency for NPP (LUE) on an annual basis as the ratio of NPP to APAR. We analysed the relative importance for NPP of APAR and LUE. The analyses consider the global values of these factors, their spatial patterns represented by latitudinal variations, and the overall grid cell by grid cell variability. Spatial variability in NPP within a model proved to be determined by APAR, and differences among models by LUE. There was a compensation between APAR and LUE, so that global NPP values fell within the range of ‘generally accepted values’. Overall, APAR was lower for satellite driven models than for the other models. Most computed values of LUE were within the range of published values, except for one model.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 5
Claim · model-written summary
Within models, APAR determined spatial variability in NPP.
Not reportedTaxonCompoundDirection
Verbatim
e0“Spatial variability in NPP within a model proved to be determined by APAR”
Claim · model-written summary
LUE determined differences in NPP among models.
Not reportedTaxonComparatorDirection
Verbatim
e0“differences among models by LUE”
Claim · model-written summary
APAR and LUE compensated, keeping global NPP within generally accepted values.
Not reportedTaxonComparatorDirection
Verbatim
e0“There was a compensation between APAR and LUE, so that global NPP values fell within the range of ‘generally accepted values’”
Claim · model-written summary
Satellite driven models had lower APAR than other models.
Not reportedTaxonMaterial
Verbatim
e0“Overall, APAR was lower for satellite driven models than for the other models.”
Claim · model-written summary
Most computed LUE values fell within published ranges except one model.
Not reportedTaxon
Verbatim
e0“Most computed values of LUE were within the range of published values, except for one model.”