Dynamic regulation of water potential in Juniperus osteosperma mediates ecosystem carbon fluxes (in EN)
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.
InJuniperus osteosperma, a drought‐resistant dryland conifer, we collected a 5‐month growing season time series ofin situ, high temporal‐resolution plant water potential () 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 osteospermashowed 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 allowJ. osteospermato 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.
- Research Organization:
- Univ. of Utah, Salt Lake City, UT (United States)
- Sponsoring Organization:
- USDOE; USDOE Office of Science (SC)
- Grant/Contract Number:
- SC0022052
- OSTI ID:
- 2579918
- Alternate ID(s):
- OSTI ID: 2349160
- Journal Information:
- New Phytologist, Journal Name: New Phytologist Journal Issue: 1 Vol. 243; ISSN 0028-646X
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- EN