1. Why models underestimate West African tropical forest primary productivity.
- Author
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Zhang-Zheng, Huanyuan, Deng, Xiongjie, Aguirre-Gutiérrez, Jesús, Stocker, Benjamin D., Thomson, Eleanor, Ding, Ruijie, Adu-Bredu, Stephen, Duah-Gyamfi, Akwasi, Gvozdevaite, Agne, Moore, Sam, Oliveras Menor, Imma, Prentice, I. Colin, and Malhi, Yadvinder
- Subjects
TROPICAL forests ,FOREST productivity ,CARBON cycle ,FIELD research ,REMOTE sensing - Abstract
Tropical forests dominate terrestrial photosynthesis, yet there are major contradictions in our understanding due to a lack of field studies, especially outside the tropical Americas. A recent field study indicated that West African forests have among the highest forests gross primary productivity (GPP) yet observed, contradicting models that rank them lower than Amazonian forests. Here, we show possible reasons for this data-model mismatch. We found that biometric GPP measurements are on average 56.3% higher than multiple global GPP products at the study sites. The underestimation of GPP largely disappears when a standard photosynthesis model is informed by local field-measured values of (a) fractional absorbed photosynthetic radiation (fAPAR), and (b) photosynthetic traits. Remote sensing products systematically underestimate fAPAR (33.9% on average at study sites) due to cloud contamination issues. The study highlights the potential widespread underestimation of tropical forests GPP and carbon cycling and hints at the ways forward for model and input data improvement. This study finds that vegetation models commonly underestimate the productivity of West African forests, owing to bias in fractional absorbed photosynthetic radiation (fAPAR) and leaf level photosynthetic capacities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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