Quantifying the photosynthetic capacity of dominant tree species in a humid lowland tropical forest of the Congo Basin

The Congo basin is home to the second largest tropical forest in the world Therefore, it plays a crucial role in the global carbon cycle. Yet very few field based data on related processes exist. Gaining knowledge on a species level is also crucial for understanding these ecosystems. Leaf chamber measurements allow to measure photosynthetic capacity on a leaf level and by so, quantify the photosynthetic capacity of individual species. Moreover, they allow to quantify a plant´s reaction to environmental parameters such as light, atmospheric CO₂ concentration and temperature. Such data is crucial to improve the calibration and robustness of global vegetation models. These models are key tools to estimate the global carbon budget and ecosystem responses to climate change as a part of the Intergovernmental Panel on Climate Change exercises.

To date, no such data exists for the forests of the Congo Basin which prevents us to properly understand forest dynamics and resilience to global changes.In this research, we quantify leaf level carbon uptake and its response to light, CO₂ and Temperature for dominant tree species within the footprint of the CongoFlux tower in Yangambi (DR Congo).

As such, we deliver the first in-field leaf-level photosynthetic parameters dataset for a lowland tropical forest of the Congo Basin. Doing this, we explore the controls of interspecific variation in photosynthetic capacity including plant guild, species and vertical canopy position. Our study takes place at the research site of CongoFlux, Yangambi (DR Congo).