Phosphorus enrichment does not enlarge the predicted CO2 fertilization effect on forest carbon sequestration
(2026) In Proceedings of the National Academy of Sciences of the United States of America 123(12).- Abstract
The capacity of nutrient-limited forests to enhance carbon (C) sequestration under elevated CO2 (eCO2) remains a critical uncertainty in C cycle modeling. While existing evidence suggests that low phosphorus (P) bioavailability may constrain CO2 fertilization effects on plant growth, the extent to which this limitation modulates ecosystem responses to eCO2 in forests adapted to P-deficient soils remains poorly understood. Here, using eight P-enabled models, we simulated the magnitudes and mechanisms through which P bioavailability interacts with eCO2, emulating an ecosystem-scale P enrichment experiment at a P-limited Eucalyptus forest undergoing long-term Free-Air CO2... (More)
The capacity of nutrient-limited forests to enhance carbon (C) sequestration under elevated CO2 (eCO2) remains a critical uncertainty in C cycle modeling. While existing evidence suggests that low phosphorus (P) bioavailability may constrain CO2 fertilization effects on plant growth, the extent to which this limitation modulates ecosystem responses to eCO2 in forests adapted to P-deficient soils remains poorly understood. Here, using eight P-enabled models, we simulated the magnitudes and mechanisms through which P bioavailability interacts with eCO2, emulating an ecosystem-scale P enrichment experiment at a P-limited Eucalyptus forest undergoing long-term Free-Air CO2 Enrichment. While models predicted pronounced P effects on tree growth, P enrichment unexpectedly did not increase the CO2 effects on tree growth and ecosystem C sequestration. Models prioritized either CO2-driven or P-driven growth, but rarely both. This tradeoff emerged due to model-specific assumptions on 1) partitioning of the extra P in soil labile versus nonlabile pools; 2) plant photosynthetic acclimation to P deficiency; 3) C and nutrient use strategies regulating plant size and allocation; and 4) microbial-driven soil decomposition processes. By generating divergent yet biologically plausible outcomes, these predictions establish critical testable hypotheses for empirical research and highlight multiple P-related pathways that may influence the future land C sink.
(Less)
- author
- organization
- publishing date
- 2026-03
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- carbon sequestration, CO fertilization effect, ecosystem model, forest, phosphorus limitation
- in
- Proceedings of the National Academy of Sciences of the United States of America
- volume
- 123
- issue
- 12
- article number
- e2516152123
- publisher
- National Academy of Sciences
- external identifiers
-
- pmid:41855264
- scopus:105033950939
- ISSN
- 0027-8424
- DOI
- 10.1073/pnas.2516152123
- language
- English
- LU publication?
- yes
- id
- dabb5aea-f9b9-438f-a038-55b7fbd46462
- date added to LUP
- 2026-06-10 15:30:53
- date last changed
- 2026-06-11 16:33:59
@article{dabb5aea-f9b9-438f-a038-55b7fbd46462,
abstract = {{<p>The capacity of nutrient-limited forests to enhance carbon (C) sequestration under elevated CO<sub>2</sub> (eCO<sub>2</sub>) remains a critical uncertainty in C cycle modeling. While existing evidence suggests that low phosphorus (P) bioavailability may constrain CO<sub>2</sub> fertilization effects on plant growth, the extent to which this limitation modulates ecosystem responses to eCO<sub>2</sub> in forests adapted to P-deficient soils remains poorly understood. Here, using eight P-enabled models, we simulated the magnitudes and mechanisms through which P bioavailability interacts with eCO<sub>2</sub>, emulating an ecosystem-scale P enrichment experiment at a P-limited Eucalyptus forest undergoing long-term Free-Air CO<sub>2</sub> Enrichment. While models predicted pronounced P effects on tree growth, P enrichment unexpectedly did not increase the CO<sub>2</sub> effects on tree growth and ecosystem C sequestration. Models prioritized either CO<sub>2</sub>-driven or P-driven growth, but rarely both. This tradeoff emerged due to model-specific assumptions on 1) partitioning of the extra P in soil labile versus nonlabile pools; 2) plant photosynthetic acclimation to P deficiency; 3) C and nutrient use strategies regulating plant size and allocation; and 4) microbial-driven soil decomposition processes. By generating divergent yet biologically plausible outcomes, these predictions establish critical testable hypotheses for empirical research and highlight multiple P-related pathways that may influence the future land C sink.</p>}},
author = {{Wang, Bin and Lyu, He and Zhang, Xueqian and Jiang, Mingkai and Medlyn, Belinda E. and Wårlind, David and Knauer, Jürgen and Fleischer, Katrin and Goll, Daniel S. and Olin, Stefan and Yang, Xiaojuan and Yu, Lin and Zaehle, Sönke and Zhang, Haicheng and Schufft, Kristian and Crous, Kristine Y. and Carrillo, Yolima and Macdonald, Catriona A. and Anderson, Ian C. and Boer, Matthias M. and Farrell, Mark and Gherlenda, Andrew and Castañeda-Gómez, Laura and Hasegawa, Shun and Jarosch, Klaus and Milham, Paul and Ochoa-Hueso, Raúl and Pathare, Varsha and Pihlblad, Johanna and Piñeiro, Juan and Power, Sally A. and Reich, Peter B. and Riegler, Markus and Ellsworth, David S. and Smith, Benjamin}},
issn = {{0027-8424}},
keywords = {{carbon sequestration; CO fertilization effect; ecosystem model; forest; phosphorus limitation}},
language = {{eng}},
number = {{12}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences of the United States of America}},
title = {{Phosphorus enrichment does not enlarge the predicted CO<sub>2</sub> fertilization effect on forest carbon sequestration}},
url = {{http://dx.doi.org/10.1073/pnas.2516152123}},
doi = {{10.1073/pnas.2516152123}},
volume = {{123}},
year = {{2026}},
}
