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Dynamic regulation of water potential in Juniperus osteosperma mediates ecosystem carbon fluxes
Name:
NPH19805_AM.pdf
Embargo:
2025-05-10
Size:
2.128Mb
Format:
PDF
Description:
Final Accepted Manuscript
Author
Guo, Jessica S.Barnes, Mallory L.
Smith, William K.
Anderegg, William R. L.
Kannenberg, Steven A.
Affiliation
Arizona Experiment Station, University of ArizonaSchool of Natural Resources and the Environment, University of Arizona
Issue Date
2024-05-10Keywords
carbon uptakedryland ecosystem
hydraulic regulation
iso/anisohydry
juniper woodland
precipitation pulse dynamics
stem water potential
Metadata
Show full item recordPublisher
WileyCitation
Guo, J. S., Barnes, M. L., Smith, W. K., Anderegg, W. R., & Kannenberg, S. A. (2024). Dynamic regulation of water potential in Juniperus osteosperma mediates ecosystem carbon fluxes. New Phytologist.Journal
New PhytologistRights
© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Some plants exhibit dynamic hydraulic regulation, in which the strictness of hydraulic regulation (i.e. iso/anisohydry) changes in response to environmental conditions. However, the environmental controls over iso/anisohydry and the implications of flexible hydraulic regulation for plant productivity remain unknown. In Juniperus osteosperma, a drought-resistant dryland conifer, we collected a 5-month growing season time series of in situ, high temporal-resolution plant water potential ((Formula presented.)) and stand gross primary productivity (GPP). We quantified the stringency of hydraulic regulation associated with environmental covariates and evaluated how predawn water potential contributes to empirically predicting carbon uptake. Juniperus osteosperma showed less stringent hydraulic regulation (more anisohydric) after monsoon precipitation pulses, when soil moisture and atmospheric demand were high, and corresponded with GPP pulses. Predawn water potential matched the timing of GPP fluxes and improved estimates of GPP more strongly than soil and/or atmospheric moisture, notably resolving GPP underestimation before vegetation green-up. Flexible hydraulic regulation appears to allow J. osteosperma to prolong soil water extraction and, therefore, the period of high carbon uptake following monsoon precipitation pulses. Water potential and its dynamic regulation may account for why process-based and empirical models commonly underestimate the magnitude and temporal variability of dryland GPP.Note
12 month embargo; first published 10 May 2024ISSN
0028-646XEISSN
1469-8137Version
Final accepted manuscriptSponsors
U.S. Forest Serviceae974a485f413a2113503eed53cd6c53
10.1111/nph.19805