Improving intra‐ and inter‐annual GPP predictions by using individual tree inventories and leaf growth dynamics

TitleImproving intra‐ and inter‐annual GPP predictions by using individual tree inventories and leaf growth dynamics
Publication TypeJournal Article
Year of Publication2021
AuthorsFang J, Lutz JA, Shugart HH, Yan X, Xie W, Liu F
JournalJournal of Applied Ecology
Pagination2315 - 2328
Date PublishedJan-10-2021
  1. Carbon sequestration is a key ecosystem service provided by forests. Inventory data based on individual trees are considered to be the most accurate method for estimating forest productivity. However, the estimations of forest photosyn-thesis from inventory data remain understudied, particularly when considering the growth and development of individual trees under the background of global change.
  2. Here, we used the leaf growth process with phenology and non-structural car-bohydrates (NSC) storage to revise an individual-tree- based carbon model, FORCCHN. This model couples leaf development and biomass to quantify gross primary productivity (GPP) in the forests, where growth is decoupled from photo-synthesis in daily step. The model was initialized with inventory- based forest data rather than the more widely used satellite- based data.
  3. We tested the model against measured above- ground woody biomass, growth of leaf biomass, daily gross ecosystem exchange (GEE) and yearly GEE at five repre-sentative forest sites in the Northern Hemisphere. We also compared the results from the original model and the revised model at five forest sites. Including leaf growth dynamics and inventory- based initialization improved the predicted per-formance (r2) of GPP by an average of 33%.
  4. Synthesis and applications. Our results suggest that the appropriate vegetation data sources (i.e. inventory or satellite selection) and the effective predictions of the growth process should be considered when developing future carbon cycle models and forest carbon estimation options. Applying and improving such car-bon models to evaluate carbon sequestration is an important part of forest carbon sink management.
Short TitleJ Appl Ecol
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