Abstract
This study extends the Hi-sAFe agroforestry model by incorporating the effects of elevated atmospheric CO2 on tree growth. Hi-sAFe is a process-based biophysical model that represents tree–crop interactions, but until now lacked a mechanism to simulate CO2-driven physiological responses of trees. We introduced CO2 sensitivity into the Light Use Efficiency (LUE) module and simulated the growth of Juglans nigra (black walnut) under current and future climate conditions (550 ppm CO2, + 3 °C, − 10% precipitation). Elevated CO2 increased tree height, diameter and root development in both forestry and agroforestry systems, but responses were stronger and more persistent in forestry. In agroforestry, CO2 effects were more variable over time and were strongly modulated by competition with crops, while belowground responses indicated greater root system plasticity. Climate change reduced tree growth in both systems, but CO2 partially offset these effects, particularly in forestry. These results demonstrated the importance of explicitly representing CO2 fertilisation in agroforestry models to realistically capture vegetation–climate interactions and assess the resilience of tree–crop systems under global change.
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Funding
This work was supported by CLAND (ANR-16-CONV-0003) and Kano State Government of Nigeria. Additional funding was provided by the European Union through the DigitAF project under grant agreement: 101059794. Views and opinions expressed are however those of the author only and do not necessarily reflect those of the European Union. The European Union cannot be held responsible for them.
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Mahmud, M., Gosme, M., Lecomte, I. et al. Simulating tree responses to elevated CO2 and climate change in agroforestry system.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-50349-w
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DOI: https://doi.org/10.1038/s41598-026-50349-w
Keywords
- Elevated CO2
- Agroforestry
- Modelling
- Hi-sAFe
- Tree
- Photosynthesis
Source: Ecology - nature.com
