---
OA_place: publisher
OA_type: free access
_id: '22536'
abstract:
- lang: eng
text: Increasing concentrations of atmospheric carbon dioxide are expected to affect
carbon assimilation and evapotranspiration (ET), ultimately driving changes in
plant growth, hydrology, and the global carbon balance. Direct leaf biochemical
effects have been widely investigated, whereas indirect effects, although documented,
elude explicit quantification in experiments. Here, we used a mechanistic model
to investigate the relative contributions of direct (through carbon assimilation)
and indirect (via soil moisture savings due to stomatal closure, and changes in
leaf area index) effects of elevated CO2 across a variety of ecosystems. We specifically
determined which ecosystems and climatic conditions maximize the indirect effects
of elevated CO2. The simulations suggest that the indirect effects of elevated
CO2 on net primary productivity are large and variable, ranging from less than
10% to more than 100% of the size of direct effects. For ET, indirect effects
were, on average, 65% of the size of direct effects. Indirect effects tended to
be considerably larger in water-limited ecosystems. As a consequence, the total
CO2 effect had a significant, inverse relationship with the wetness index and
was directly related to vapor pressure deficit. These results have major implications
for our understanding of the CO2 response of ecosystems and for global projections
of CO2 fertilization, because, although direct effects are typically understood
and easily reproducible in models, simulations of indirect effects are far more
challenging and difficult to constrain. Our findings also provide an explanation
for the discrepancies between experiments in the total CO2 effect on net primary
productivity.
article_processing_charge: No
article_type: original
author:
- first_name: Simone
full_name: Fatichi, Simone
id: cf8e546b-a9b0-11f0-a43b-aa89ed1b56d6
last_name: Fatichi
- first_name: Sebastian
full_name: Leuzinger, Sebastian
last_name: Leuzinger
- first_name: Athanasios
full_name: Paschalis, Athanasios
last_name: Paschalis
- first_name: J. Adam
full_name: Langley, J. Adam
last_name: Langley
- first_name: Alicia
full_name: Donnellan Barraclough, Alicia
last_name: Donnellan Barraclough
- first_name: Mark J.
full_name: Hovenden, Mark J.
last_name: Hovenden
citation:
ama: Fatichi S, Leuzinger S, Paschalis A, Langley JA, Donnellan Barraclough A, Hovenden
MJ. Partitioning direct and indirect effects reveals the response of water-limited
ecosystems to elevated CO. Proceedings of the National Academy of Sciences.
2016;113(45):12757-12762. doi:10.1073/pnas.1605036113
apa: Fatichi, S., Leuzinger, S., Paschalis, A., Langley, J. A., Donnellan Barraclough,
A., & Hovenden, M. J. (2016). Partitioning direct and indirect effects reveals
the response of water-limited ecosystems to elevated CO. Proceedings of the
National Academy of Sciences. National Academy of Sciences. https://doi.org/10.1073/pnas.1605036113
chicago: Fatichi, Simone, Sebastian Leuzinger, Athanasios Paschalis, J. Adam Langley,
Alicia Donnellan Barraclough, and Mark J. Hovenden. “Partitioning Direct and Indirect
Effects Reveals the Response of Water-Limited Ecosystems to Elevated CO.” Proceedings
of the National Academy of Sciences. National Academy of Sciences, 2016. https://doi.org/10.1073/pnas.1605036113.
ieee: S. Fatichi, S. Leuzinger, A. Paschalis, J. A. Langley, A. Donnellan Barraclough,
and M. J. Hovenden, “Partitioning direct and indirect effects reveals the response
of water-limited ecosystems to elevated CO,” Proceedings of the National Academy
of Sciences, vol. 113, no. 45. National Academy of Sciences, pp. 12757–12762,
2016.
ista: Fatichi S, Leuzinger S, Paschalis A, Langley JA, Donnellan Barraclough A,
Hovenden MJ. 2016. Partitioning direct and indirect effects reveals the response
of water-limited ecosystems to elevated CO. Proceedings of the National Academy
of Sciences. 113(45), 12757–12762.
mla: Fatichi, Simone, et al. “Partitioning Direct and Indirect Effects Reveals the
Response of Water-Limited Ecosystems to Elevated CO.” Proceedings of the National
Academy of Sciences, vol. 113, no. 45, National Academy of Sciences, 2016,
pp. 12757–62, doi:10.1073/pnas.1605036113.
short: S. Fatichi, S. Leuzinger, A. Paschalis, J.A. Langley, A. Donnellan Barraclough,
M.J. Hovenden, Proceedings of the National Academy of Sciences 113 (2016) 12757–12762.
das_tickbox: '1'
date_created: 2026-07-27T12:30:24Z
date_published: 2016-11-08T00:00:00Z
date_updated: 2026-08-06T08:08:46Z
day: '08'
doi: 10.1073/pnas.1605036113
extern: '1'
external_id:
pmid:
- '27791074'
intvolume: ' 113'
issue: '45'
keyword:
- carbon dioxide
- modeling
- FACE
- soil moisture
- evapotranspiration
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1073/pnas.1605036113
month: '11'
oa: 1
oa_version: Published Version
page: 12757-12762
pmid: 1
publication: Proceedings of the National Academy of Sciences
publication_identifier:
eissn:
- 1091-6490
issn:
- 0027-8424
publication_status: published
publisher: National Academy of Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: Partitioning direct and indirect effects reveals the response of water-limited
ecosystems to elevated CO
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 113
year: '2016'
...