scholarly journals The diversity of 13C isotope discrimination in a Quercus robur full-sib family is associated with differences in intrinsic water use efficiency, transpiration efficiency, and stomatal conductance

2009 ◽  
Vol 60 (8) ◽  
pp. 2419-2431 ◽  
Author(s):  
Magali Roussel ◽  
Erwin Dreyer ◽  
Pierre Montpied ◽  
Grégoire Le-Provost ◽  
Jean-Marc Guehl ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Quercus Robur ◽  
Transpiration Efficiency ◽  
Isotope Discrimination ◽  
13C Isotope ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

scholarly journals Apparent Tolerance of Low Water Availability in Temperate Asian Bamboos1

2018 ◽  
Vol 36 (1) ◽  
pp. 7-13
Author(s):  
Melissa C. Smith ◽  
Richard N. Mack
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
North American ◽  
Water Availability ◽  
Irrigation Treatment ◽  
Bamboo Species ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Pleioblastus Chino

Abstract Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia but play only an incidental role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.

scholarly journals 20th-century changes in carbon isotopes and water-use efficiency: Tree-ring based evaluation of the CLM4.5 and LPX-Bern models

2016 ◽  
Author(s):  
Kathrin M. Keller ◽  
Sebastian Lienert ◽  
Anil Bozbiyik ◽  
Thomas F. Stocker ◽  
Olga V. Churakova ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
20Th Century ◽  
Water Use ◽  
Tree Ring ◽  
Dynamic Global Vegetation Model ◽  
Isotopic Discrimination ◽  
Tree Ring Data ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

Abstract. Measurements of the stable carbon isotope ratio (δ13C) on annual tree rings offer new opportunities to evaluate mechanisms of variations in photosynthesis and stomatal conductance under changing CO2 and climate, especially in conjunction with process-based biogeochemical model simulations. The isotopic discrimination is indicative of the ratio between the CO2 partial pressure in the intercellular cavities and the atmosphere (ci / ca) and of the ratio of assimilation to stomatal conductance, termed intrinsic water-use efficiency (iWUE). We performed isotope-enabled simulations over the industrial period with the land biosphere module (CLM4.5) of the Community Earth System Model and the LPX-Bern dynamic global vegetation model. Results for C3 tree species show good agreement with a global compilation of δ13C measurements on leaves, though modeled 13C discrimination by C3 trees is smaller in arid regions than measured. A compilation of seventy-six tree-ring records, mainly from Europe, boreal Asia, and western North America, suggest on average small 20th-century changes in isotopic discrimination and an increase in iWUE of about 27 % since 1900. LPX-Bern results match these century-scale reconstructions, supporting the idea that the physiology of stomata has evolved to optimize trade-offs between carbon gain by assimilation and water loss. In contrast, CLM4.5 simulates an increase in discrimination and in turn a change in iWUE that is almost twice as large as revealed by the tree-ring data. Factorial simulations show that these changes are mainly in response to rising atmospheric CO2. The results suggest that the down-regulation of ci / ca and of photosynthesis by nitrogen limitation is possibly too strong in the standard setup of CLM4.5 or there may be more fundamental problems associated with the prescribed relationship between conductance and assimilation.

scholarly journals Intrinsic water use efficiency depends on stomatal aperture rather than stomatal density in C3 and C4 grasses grown at glacial CO2 and low light

2021 ◽  
Author(s):  
Walter K Israel ◽  
Alex Watson-Lazowski ◽  
Zhong-Hua Chen ◽  
Oula Ghannoum
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Stomatal Density ◽  
Stomatal Aperture ◽  
C4 Grasses ◽  
Low Light ◽  
Influx Rate ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

We investigated how stomatal morphology and physiology control intrinsic leaf water use efficiency (iWUE) in grasses. Two C3 and six C4 grasses were grown at ambient (400 μl L-1) or glacial CO2 (180 μl L-1) and high (1000 μmol m-2 s-1) or low light intensity (200 μmol m-2 s-1). C4 grasses tended to have higher iWUE and CO2 assimilation rates, and lower stomatal conductance (gs), operational stomatal aperture (aop) and guard cell K+ influx rate relative to C3 grasses, while stomatal size (SS) and stomatal density (SD) did not vary according to the photosynthetic type. Overall, iWUE and gs depended most on aop and density of open stomata. In turn, aop correlated with K+ influx, stomatal opening speed on transition to high light and SS. Species with higher SD had smaller and faster-opening stomata. Although C4 grasses operated with lower gs and aop at ambient CO2, they showed a greater potential to open stomata relative to maximal stomatal conductance (gmax), indicating heightened stomatal sensitivity and control. We uncover novel links between aop, gs, iWUE and K+ influx amongst grasses and differential K+ influx responses of C4 guard cells to low light, revealing molecular targets for breeding crops with high iWUE.

scholarly journals 20th century changes in carbon isotopes and water-use efficiency: tree-ring-based evaluation of the CLM4.5 and LPX-Bern models

2017 ◽  
Vol 14 (10) ◽  
pp. 2641-2673 ◽  
Author(s):  
Kathrin M. Keller ◽  
Sebastian Lienert ◽  
Anil Bozbiyik ◽  
Thomas F. Stocker ◽  
Olga V. Churakova (Sidorova) ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
20Th Century ◽  
Water Use ◽  
Tree Ring ◽  
Dynamic Global Vegetation Model ◽  
Isotopic Discrimination ◽  
Tree Ring Data ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

Abstract. Measurements of the stable carbon isotope ratio (δ13C) on annual tree rings offer new opportunities to evaluate mechanisms of variations in photosynthesis and stomatal conductance under changing CO2 and climate conditions, especially in conjunction with process-based biogeochemical model simulations. The isotopic discrimination is indicative of the ratio between the CO2 partial pressure in the intercellular cavities and the atmosphere (ci∕ca) and of the ratio of assimilation to stomatal conductance, termed intrinsic water-use efficiency (iWUE). We performed isotope-enabled simulations over the industrial period with the land biosphere module (CLM4.5) of the Community Earth System Model and the Land Surface Processes and Exchanges (LPX-Bern) dynamic global vegetation model. Results for C3 tree species show good agreement with a global compilation of δ13C measurements on leaves, though modeled 13C discrimination by C3 trees is smaller in arid regions than measured. A compilation of 76 tree-ring records, mainly from Europe, boreal Asia, and western North America, suggests on average small 20th century changes in isotopic discrimination and in ci∕ca and an increase in iWUE of about 27 % since 1900. LPX-Bern results match these century-scale reconstructions, supporting the idea that the physiology of stomata has evolved to optimize trade-offs between carbon gain by assimilation and water loss by transpiration. In contrast, CLM4.5 simulates an increase in discrimination and in turn a change in iWUE that is almost twice as large as that revealed by the tree-ring data. Factorial simulations show that these changes are mainly in response to rising atmospheric CO2. The results suggest that the downregulation of ci∕ca and of photosynthesis by nitrogen limitation is possibly too strong in the standard setup of CLM4.5 or that there may be problems associated with the implementation of conductance, assimilation, and related adjustment processes on long-term environmental changes.

scholarly journals Effects of Postharvest Water Deficits on the Physiological Behavior of Early-Maturing Nectarine Trees

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1104
Author(s):  
María R. Conesa ◽  
Wenceslao Conejero ◽  
Juan Vera ◽  
M. Carmen Ruiz-Sánchez
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Strong Dependence ◽  
Stomatal Closure ◽  
Stem Water Potential ◽  
Water Deficits ◽  
Intrinsic Water Use Efficiency ◽  
Early Maturing ◽  
Use Efficiency

The physiological performance of early-maturing nectarine trees in response to water deficits was studied during the postharvest period. Two deficit irrigation treatments were applied, moderate and severe, and these were compared with a control treatment (fully irrigated). Stem water potential and leaf gas exchange (net CO2 assimilation rate, ACO2; transpiration rate, E; and stomatal conductance, gs) were measured frequently. Drought avoidance mechanisms included a decrease in stomatal conductance, especially in the case of the severe deficit treatment, which also showed a strong dependence of ACO2 on gs. Intrinsic water-use efficiency (ACO2/gs) was more sensitive than instantaneous water-use efficiency (ACO2/E) as an indicator to detect water deficit situations in nectarine trees. However, in contrast to the results obtained for other deciduous fruit trees, a poor correlation was found between ACO2/E and ACO2/gs, despite the important relation between E and gs. ACO2/E was also weakly correlated with gs, although this relationship clearly improved when the vapor pressure deficit (VPD) was included, along with gs as the independent variable. This fact reveals that apart from stomatal closure, E depends on the boundary layer conductance (gb), which is mediated by VPD through changes in wind speed. This suggests low values of the decoupling coefficient for this water-resilient species.

scholarly journals Physiological and Morphological Variation in Balsam Fir Provenances Growing in New Brunswick, Canada

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 186
Author(s):  
Matthew E. Akalusi ◽  
Charles P.-A. Bourque
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Common Garden ◽  
Climatic Conditions ◽  
Balsam Fir ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

There is a need to understand the physio-morphological responses of northern tree species to climate change. The hypothesis of the current study was that provenance and light intensity were both influential in the control of intrinsic water-use efficiency (iWUE). Diameter at breast height (DBH)-increment was hypothesized as being more affected by provenance. Intrinsic water-use efficiency (iWUE), the ratio of photosynthesis (A) to stomatal conductance (gs), was assessed in foliage under two levels of photosynthetically active radiation (PAR; i.e., 300 and 1200 μmol m−2 s−1) in 63-year-old balsam fir [Abies balsamea (L.) Mill.] provenances derived from seed sources from across the species’ natural range (namely, within 44–51° N latitudes and 53–102° W longitudes) and cultivated in a common garden in eastern Canada. Diameter at breast height (DBH) of provenances from the common garden were measured when they were 42 and 58 years old (DBH1998, DBH2014). The results confirmed the hypotheses regarding the roles of provenance on iWUE and DBH (p < 0.05), but showed a diminished role of PAR on iWUE. The lowest and highest mean iWUE and DBH among the provenances ranged between 0.028 and 0.031 and 0.079–0.083 μmol mmol−1 and 11.82–12.78 and 16.38–18.44 cm, respectively. Stomatal conductance of balsam fir had a strong relationship with iWUE at both light settings, whereas A had a weaker relationship with iWUE. There were no significant relationships between iWUE at the two light settings and climatic variables at the provenance source (p > 0.05). Diameter at breast height in 2014 was significantly greater than DBH1998 (p < 0.05). The relationships between DBH2014 and climatic variables at the provenance source were statistically significant (p < 0.05). There was a significant positive relationship between iWUE and DBH measured in 2014. Survivorship of provenances was shown to vary with DBH-increment. The results show that for present-day and future forest management, (i) selection in balsam fir, in relation to iWUE should ideally be based on a criterion of intraspecific stomatal conductance; (ii) shade tolerance of balsam fir, population differentiation, and consistent pace of DBH-growth under variable climatic conditions are important factors in the species’ sustained growth under changes in forest dynamics projected to accompany changes in regional climate; (iii) temperature variables are strong indicators of DBH-increment in balsam fir; (iv) the effect of tree size on its survival is maintained under variable climatic conditions; and (v) there is a clear association between iWUE and the species’ radial growth.

Sign in / Sign up

Export Citation Format

Share Document