Your browser doesn't support javascript.
loading
Dynamic regulation of water potential in Juniperus osteosperma mediates ecosystem carbon fluxes.
Guo, Jessica S; Barnes, Mallory L; Smith, William K; Anderegg, William R L; Kannenberg, Steven A.
Afiliação
  • Guo JS; Arizona Experiment Station, University of Arizona, Tucson, AZ, 85721, USA.
  • Barnes ML; O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN, 47405, USA.
  • Smith WK; School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, 85721, USA.
  • Anderegg WRL; School of Biological Sciences and Wilkes Center for Climate Science and Policy, University of Utah, Salt Lake City, UT, 84112, USA.
  • Kannenberg SA; Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, 805023, USA.
New Phytol ; 243(1): 98-110, 2024 Jul.
Article em En | MEDLINE | ID: mdl-38725410
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 ( Ψ ) 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.
Assuntos
Palavras-chave

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Carbono / Água / Ecossistema / Juniperus / Ciclo do Carbono Idioma: En Ano de publicação: 2024 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Carbono / Água / Ecossistema / Juniperus / Ciclo do Carbono Idioma: En Ano de publicação: 2024 Tipo de documento: Article