Geographic variation in ecophysiological traits of black cottonwood (Populus trichocarpa)This article is one of a selection of papers published in the Special Issue on Poplar Research in Canada.

2007 ◽  
Vol 85 (12) ◽  
pp. 1202-1213 ◽  
Author(s):  
Jemma L. Gornall ◽  
Robert D. Guy
Keyword(s):  
Water Use ◽  
Stomatal Density ◽  
Isotope Composition ◽  
Populus Trichocarpa ◽  
Stable Carbon Isotope ◽  
Common Garden ◽  
Leaf Nitrogen ◽  
Black Cottonwood ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

Variation in traits related to photosynthesis and water-use were examined within and between geographic sources (provenances) of black cottonwood in two range-wide common garden experiments in British Columbia, Canada. In the first experiment, CO2 assimilation (A), stomatal conductance (gs), instantaneous intrinsic water use efficiency (WUEi), stomatal density, specific leaf area, growth height, and foliar N were measured on five 2-year-old trees of 20 clones from five widely separated provenances (i.e., 4 clones per source). Leaf disks were analysed for stable carbon isotope composition (δ13C) to provide a more long-term measure of WUE. Photosynthetic rate per unit leaf nitrogen was used as a measure of nitrogen use efficiency (NUE). A differed between (p < 0.001), but not within provenances, and increased with latitude of origin (R2 = 0.70). NUE and WUEi also varied between (p = 0.034 and p = 0.039, respectively), but not within provenances. In contrast, no variation among provenances was detected for δ13C, but there were strong differences between clones within provenances (p < 0.001). Variation in A was well correlated with foliar nitrogen, gs, and stomatal density and adaxial:abaxial distribution ratio; hence, WUEi, δ13C and NUE were mostly unrelated to latitude or associated climate variables. Species-wide patterns in stomatal density and distribution were confirmed in the second experiment which utilized 140 clones. Stomatal density on the adaxial (but not the abaxial) leaf surface was strongly correlated with latitude (p <0.001). We speculate that northern provenances may have inherently higher A and gs to compensate for shorter growing seasons.

The effects of sodium sulphate and sodium chloride on growth, morphology, photosynthesis, and water use efficiency of Chenopodium rubrum

1990 ◽  
Vol 68 (5) ◽  
pp. 999-1006 ◽  
Author(s):  
Patricia Warne ◽  
R. D. Guy ◽  
Lorna Rollins ◽  
D. M. Reid
Keyword(s):  
Sodium Chloride ◽  
Water Use Efficiency ◽  
Water Use ◽  
Stomatal Density ◽  
Stable Carbon Isotope ◽  
Dry Weight ◽  
Sodium Sulphate ◽  
Chenopodium Rubrum ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

The effects of sodium sulphate and sodium chloride salinity on the anatomy, water relations, and photosynthesis of Chenopodium rubrum L. were compared. Low concentrations of either salt stimulated growth, but higher concentrations resulted in large decreases in dry weight and leaf area. Leaf succulence and the number of layers of palisade cells were increased, but these effects were more pronounced with NaCl than with Na2SO4. Stomatal density was reduced at low to moderate salinities, but then increased again at high salinity. Stomatal size was reduced at all salinities. Increasing salinity had no great effect on photosynthetic rates except with older plants grown at the highest level of Na2SO4. Stomatal conductance decreased at all salinities. This reduced transpiration and led to increased intrinsic water use efficiency. Total tissue stable carbon isotope ratios also indicated that water use efficiency was improved. Chenopodium rubrum adjusted osmotically by accumulating electrolytes from the nutrient solution and by synthesizing glycinebetaine. Plants in NaCl limited osmotic adjustment more than those growing in Na2SO4. Despite this, Na2SO4 was more damaging than NaCl and caused earlier leaf senescence at high concentrations.

scholarly journals The use of physiological, biochemical and morpho-anatomical traits in tree breeding for improved water-use efficiency of Quercus robur L.

2019 ◽  
Vol 28 (3) ◽  
pp. e017
Author(s):  
Srđan Stojnić ◽  
Branislav Kovačević ◽  
Marko Kebert ◽  
Erna Vaštag ◽  
Mirjana Bojović ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Stepwise Regression ◽  
Stomatal Density ◽  
Common Garden ◽  
Path Coefficient ◽  
Common Garden Experiment ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
One Year

Aim of study: In the present paper we studied the nature and level of co-dependence between leaf functional traits and intrinsic water-use efficiency (WUEi)in one-year-old Quercus roburL. seedlings, grown in a common garden experiment under moderate drought conditions. The study aimed to identify those traits that might be potentially utilized to improve leaf-level WUEi, and therefore be used in breeding programmes to enhance drought adaptation of Q. roburtree species.Area of study: The study was carried out at the common garden experiment established within UNESCO Biosphere Reserve Mura-Drava-Danube.Material and methods: The study involved one-year-old seedlings of eight half-sib lines of Q. robur. We analyzed 18 leaf parameters; i.e. physiological, biochemical, morphological and anatomical. Data were processed using multivariate statistical methods: a) principal component analysis, b) stepwise regression analysis, and c) path coefficient analysis.Main results: The results evidenced that leaf stomatal traits, particularly stomatal density (SD),and leaf dry mass per unit leaf area (LMA) were the most important traits associated closely with WUEi.Stomatal density achieved the highest score on PC1 (0.825), in which WUEihad the highest loading (0.920), as well. SDwas also included first in stepwise regression model. Research highlights: The results demonstrated that under moderate water stressWUEiin Q. robur half-sib lines were mainly the result of the plants’ structural acclimation to surrounding environmental conditions.

Physiological acclimation of Pinus flexilis to drought stress on contrasting slope aspects in Waterton Lakes National Park, Alberta, Canada

2009 ◽  
Vol 39 (3) ◽  
pp. 629-641 ◽  
Author(s):  
Matthew G. Letts ◽  
Kevin N. Nakonechny ◽  
K. Eric Van Gaalen ◽  
Cyndi M. Smith
Keyword(s):  
Gas Exchange ◽  
Water Use ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Vapour Pressure Deficit ◽  
Net Photosynthesis ◽  
Pinus Flexilis ◽  
Limber Pine ◽  
Use Efficiency ◽  
Physiological Acclimation

Photosynthetic gas-exchange characteristics were measured in Pinus flexilis James (limber pine) during two drought years in a xeric, subalpine ecosystem of the Rocky Mountains. Limber pine exhibited conservative water-use traits, including low specific leaf area, leaf nitrogen, stomatal conductance, transpiration (E), and light-saturated net photosynthesis (Amax), but exhibited high needle longevity, water-use efficiency (Amax/E), and stable carbon isotope composition. Net photosynthesis declined strongly with leaf-to-air vapour pressure deficit, resulting in a bimodal seasonal pattern of Amax. Although very little gas exchange was observed in late summer, photosynthetic activity extended into October. The avoidance of gas exchange during high atmospheric demand maximized whole-season water-use efficiency. Leaf temperature and leaf-to-air vapour pressure deficit were higher on south-facing slopes during both moderate (2006) and severe (2007) drought. Severe drought caused lower stomatal conductance and E on the southeast-facing slope, but neither Amax nor canopy reflectance indices differed among slope aspects. Although Amax was lower in 2007 than 2006, branch-length increment did not differ. Foliar stable carbon isotope composition was higher in needles produced in dry years but did not vary among slope aspects. These results indicate that physiological acclimation to water stress prevented among-aspect differences in Amax and that shoulder-season photosynthesis may become increasingly important in a warmer climate.

Incontinence in aging leaves: deteriorating water relations with leaf age in Agastachys odorata (Proteaceae), a shrub with very long-lived leaves

2007 ◽  
Vol 34 (10) ◽  
pp. 918 ◽  
Author(s):  
Gregory J. Jordan ◽  
Timothy J. Brodribb
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Stomatal Density ◽  
Leaf Age ◽  
Carbon Assimilation ◽  
Leaf Damage ◽  
Evergreen Species ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Cuticle Thickness

This paper examines physiological characteristics of the leaves of Agastachys odorata R.Br., a wet-climate sclerophyllous shrub with very long-lived leaves. It addresses the hypothesis that cuticles become leakier to water vapour as leaves age. Astomatous cuticular conductance, whole-leaf minimum epidermal conductance, leaf damage and accumulation of epiphylls all increased several-fold with leaf age from first year growth to 10 years of age. Maximum carbon assimilation peaked 1 year after full leaf expansion, then declined. Intrinsic water use efficiency was highest in mid-aged leaves and declined markedly in the oldest leaves. Stomatal density, stomatal size and cuticle thickness did not vary significantly among ages. The older leaves were less effective at controlling water loss, resulting in decreases in water use efficiency. A differential increase in the conductance of the stomatal surface of the leaves relative to astomatous surface suggested that stomatal leakiness was significant in leaves over five years old. Although data for other species is ambiguous, the deterioration in A. odorata appears to be consistent with changes in the oldest leaves of other species. Thus, decreasing ability to use water efficiently appears to be a consequence of accumulated damage and may contribute to the need for leaf senescence in evergreen species with little self shading.

scholarly journals Recent trends in the intrinsic water-use efficiency of ringless rainforest trees in Borneo

2011 ◽  
Vol 366 (1582) ◽  
pp. 3330-3339 ◽  
Author(s):  
N. J. Loader ◽  
R. P. D. Walsh ◽  
I. Robertson ◽  
K. Bidin ◽  
R. C. Ong ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Atmospheric Carbon Dioxide ◽  
Stable Carbon Isotope ◽  
Carbon Dioxide Concentration ◽  
Environmental Data ◽  
Primary Forest ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Equatorial Climate

Stable carbon isotope ( δ 13 C) series were developed from analysis of sequential radial wood increments from AD 1850 to AD 2009 for four mature primary rainforest trees from the Danum and Imbak areas of Sabah, Malaysia. The aseasonal equatorial climate meant that conventional dendrochronology was not possible as the tree species investigated do not exhibit clear annual rings or dateable growth bands. Chronology was established using radiocarbon dating to model age–growth relationships and date the carbon isotopic series from which the intrinsic water-use efficiency (IWUE) was calculated. The two Eusideroxylon zwageri trees from Imbak yielded ages of their pith/central wood (±1 sigma) of 670 ± 40 and 759 ± 40 years old; the less dense Shorea johorensis and Shorea superba trees at Danum yielded ages of 240 ± 40 and 330 ± 40 years, respectively. All trees studied exhibit an increase in the IWUE since AD 1960. This reflects, in part, a response of the forest to increasing atmospheric carbon dioxide concentration. Unlike studies of some northern European trees, no clear plateau in this response was observed. A change in the IWUE implies an associated modification of the local carbon and/or hydrological cycles. To resolve these uncertainties, a shift in emphasis away from high-resolution studies towards long, well-replicated time series is proposed to develop the environmental data essential for model evaluation. Identification of old (greater than 700 years) ringless trees demonstrates their potential in assessing the impacts of climatic and atmospheric change. It also shows the scientific and applied value of a conservation policy that ensures the survival of primary forest containing particularly old trees (as in Imbak Canyon and Danum).

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.

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