Constraining long-term model predictions for woody growth using tropical tree rings

Area of Science:

• Ecology
• Climate Science
• Forestry

Background:

• Tropical carbon sinks are vital for climate regulation.
• Woody growth responses to climate change and CO2 are uncertain.
• Accurate predictions require understanding tropical forest dynamics.

Purpose of the Study:

• To constrain a terrestrial biosphere model (ED2.2-hydro) using tropical tree-ring data.
• To assess individual-level woody growth responses to climate and CO2.
• To improve predictions of tropical forest carbon sequestration.

Main Methods:

• Utilized tree ring records from a Southeast Asian tropical forest.
• Constrained the ED2.2-hydro model with historical climate and CO2 data.
• Compared model simulations with tree ring carbon isotope and growth data.

Main Results:

• Model accurately simulated intercellular CO2 increases but overestimated woody growth trends.
• Woody biomass production efficiency (WBPE) was overestimated by the model.
• Model overestimated climate sensitivity of woody growth, particularly for late-successional species.

Conclusions:

• Improving WBPE parameterization in models is crucial for accurate tropical forest predictions.
• Model-data discrepancies highlight the need for refined understanding of carbon allocation and use efficiency.
• Better WBPE parameterization can reduce overestimations of CO2 fertilization effects on tropical forests.