Potential role of soil moisture deficit in the distribution of Cakile edentula

1986 ◽  
Vol 64 (11) ◽  
pp. 2789-2791 ◽  
Author(s):  
R. Wayne Tyndall ◽  
Alan H. Teramura ◽  
Larry W. Douglass

Soil water potential, leaf water potential, and stomatal conductance of Cakile edentula (Bigelow) Hooker were compared between beach and foredune habitats on Currituck Bank, North Carolina. All three variables were significantly lower on the foredune than on the beach. Low soil water potential on the foredune may contribute to low survival and growth inhibition by lowering leaf water potential and stomatal conductance.

2014 ◽  
Vol 20 ◽  
pp. 115-121
Author(s):  
K. Poudyal

Quercus semecarpifolia is a high altitude oak and dominant species of central Himalayan vegetation.In the central Himalaya, plants are subjected to a prolonged dry period, thus developing moisturestress. Soil water potential at 15 cm and 30 cm depth, predawn and midday leaf water potential andtheir relationship with stomatal conductance and phenological behaviour was studied at PhulchowkiHill, Kathmandu to evaluate the drought adaptation strategy of Q. semecarpifolia in a pure stand at2130 m elevation. The natural ecosystem of Himalayan region has a characteristic climatic pattern ofconcentrated rainfall and a prolonged dry season which have a strong effect on the adaptability of thisspecies. It maintained a high predawn leaf water potential (ΨL pd) and stomatal conductance (gw)despite low soil water Ψ and ΨL pd . Lowest Ψs and ΨL pd were observed in March 1999, when therewas almost no rain for five months. Mean ΨL pd and ΨL md were (–1.79 and –2.29 MPa, respectively).Patterns of ΨL pd and ΨL md correlated significantly with soil Ψ, and phenology as ΨL pd oftenincreased during leafing but not with gw.DOI: http://dx.doi.org/10.3126/eco.v20i0.11473ECOPRINT An International Journal of EcologyVol. 20, 2013page: 115-121


2004 ◽  
Vol 31 (1) ◽  
pp. 41 ◽  
Author(s):  
Marion Maurel ◽  
Cécile Robin ◽  
Thierry Simonneau ◽  
Denis Loustau ◽  
Erwin Dreyer ◽  
...  

The effects of root infection by Phytophthora cinnamomi on stomatal conductance in Castanea sativa L. saplings were investigated to determine the potential role of root-derived chemical signals. A split-root experiment was carried out, in which inoculation of the pathogen or drought was applied to the root systems in either one or both compartments. At the end of the experiment plant sap extracts were collected and their effects on stomatal conductance were determined by leaf bioassay. Inoculation or drought imposed in both compartments resulted in decreases in stomatal conductance (gs), transpiration rate, soil-to-leaf specific hydraulic conductance, leaf water potential, xylem [ABA] and root biomass, but not in the ratio of root-to-leaf mass in inoculated plants. Conversely, only gs and xylem [ABA] were affected in plants inoculated or droughted in one compartment, and no changes were detectable in leaf water potential and soil-to-leaf specific hydraulic conductance. The leaf bioassay showed that gs in chestnut was sensitive to ABA but not to Phytophthora elicitins. Stomatal conductance was reduced by some sap extracts, both from control and inoculated plants. Our results suggest the involvement of different signals, chemical and hydraulic, in regulating stomatal conductance of chestnut at different stages of stress.


1989 ◽  
Vol 16 (3) ◽  
pp. 241 ◽  
Author(s):  
NZ Saliendra ◽  
FC Meinzer

Stomatal conductance, leaf and soil water status, transpiration, and apparent root hydraulic conductance were measured during soil drying cycles for three sugarcane cultivars growing in containers in a greenhouse. At high soil moisture, transpiration and apparent root hydraulic conductance differed considerably among cultivars and were positively correlated, whereas leaf water potential was similar among cultivars. In drying soil, stomatal and apparent root hydraulic conductance approached zero over a narrow (0.1 MPa) range of soil water suction. Leaf water potential remained nearly constant during soil drying because the vapor phase conductance of the leaves and the apparent liquid phase conductance of the root system declined in parallel. The decline in apparent root hydraulic conductance with soil drying was manifested as a large increase in the hydrostatic pressure gradient between the soil and the root xylem. These results suggested that control of stomatal conductance in sugarcane plants exposed to drying soil was exerted primarily at the root rather than at the leaf level.


1974 ◽  
Vol 66 (6) ◽  
pp. 795-798 ◽  
Author(s):  
R. A. Brady ◽  
W. L. Powers ◽  
L. R. Stone ◽  
S. M. Goltz

2010 ◽  
Vol 20 (3) ◽  
pp. 585-593 ◽  
Author(s):  
Ana Centeno ◽  
Pilar Baeza ◽  
José Ramón Lissarrague

Limited water supply in arid and semiarid Mediterranean environments demands improving irrigation efficiency. The purpose of this study was to determine a functional relationship between soil water availability and wine grape (Vitis vinifera) water status to determine a threshold value of soil matric potential to trigger irrigation. Seasonal trends of soil water potential, leaf water potential, and stomatal conductance (gS) of ‘Tempranillo’ wine grape were determined in two deficit irrigation treatments replenishing 45% and 30% of the reference evapotranspiration, and in a third non-irrigated treatment during 2001 and 2002. Soil water potential was measured with granular matrix soil moisture sensors placed at 0.3 m (Ψ0.3), 0.6 m (Ψ0.6), and 1.2 m (Ψ1.2) depths. The sensors at 0.3 m depth quickly responded to irrigation by increasing Ψ0.3 levels. At the 0.6 m depth, Ψ0.6 progressively decreased, showing significant differences between T1 and the rest of the treatments, while no significant differences in Ψ1.2 were found. All relationships between profile soil matric potential and leaf water potential and gS were highly correlated. After integrating our data with previous studies, we suggest a whole profile soil water potential value of –0.12 MPa as threshold to trigger irrigation and avoid severe water stress during berry growth.


1978 ◽  
Vol 18 (92) ◽  
pp. 423 ◽  
Author(s):  
MJ Fisher

Following burning (day 0) of a water-stressed sward of green panic and siratro, measurements were made both on unburned plants and on regrowth of burned plants of leaf water potential (�s) and stomatal conductance (gs) at 1.00 p.m. and of leaf extension. In the unburned plants �s, remained low (-23 to -45 bar for green panic, and -14 to -18 bar for siratro), the stomata were closed and no growth occurred. In the burned plants of both species, however, �s on day 12 was -9 to -11 bars, the stomata were open and growth occurred, presumably because the complete defoliation allowed the plants to make use of a limited store of soil water at higher water potential. In green panic �s fell rapidly, and growth stopped after day 19, but �s and g, in siratro were still high on day 28. Burning of droughted native pastures is a common management practice in the semi-arid tropics of Australia. The data may explain how the pastures are able to make the new growth that frequently occurs.


1981 ◽  
Vol 8 (3) ◽  
pp. 347 ◽  
Author(s):  
MJ Fisher ◽  
DA Charles-Edwards ◽  
MM Ludlow

The response was measured of stomatal conductance and leaf photosynthesis to changing leaf water potential in the legume siratro subjected to a sequence of I-week cycles of increasing soil water deficit followed by watering. The response of stomatal conductance was described using a continuous mathematical function, which is more robust and accurate than the usual discontinuous linear function used to analyse such data. After seven successive cycles of water deficit, there was no apparent adjustment of the short-term response of leaf conductance to leaf water potential.


2007 ◽  
Vol 29 (2) ◽  
pp. 355-358 ◽  
Author(s):  
José Moacir Pinheiro Lima Filho

The experiment was carried out at the Embrapa Semi-Árido, Petrolina-PE, Brazil, in order to study the physiological responses of umbu plants propagated by seeds and by stem cuttings under water stress conditions, based on leaf water potential and gas exchange measurements. Data were collected in one-year plants established in pots containing 30 kg of a sandy soil and submitted to twenty-day progressive soil water deficit. The evaluations were based on leaf water potential and gas exchange data collection using psychrometric chambers and a portable infra-red gas analyzer, respectively. Plants propagated by seeds maintained a significantly higher water potential, stomatal conductance, transpiration and photosynthesis under decreasing soil water availability. However, plants propagated by stem cuttings were unable to maintain a favorable internal water balance, reflecting negatively on stomatal conductance and leaf gas exchange. This fact is probably because umbu plants propagated by stem cuttings are not prone to formation of root tubers which are reservoirs for water and solutes. Thus, the establishing of umbu plants propagated by stem cuttings must be avoided in areas subjected to soil water deficit.


Irriga ◽  
2006 ◽  
Vol 11 (4) ◽  
pp. 518-531 ◽  
Author(s):  
Maria Renata Rocha Pereira ◽  
Antônio Evaldo Klar ◽  
Magali Ribeiro da Silva ◽  
Raquel Albuquerque de Souza ◽  
Nara Rosseti Fonseca

COMPORTAMENTO FISIOLÓGICO E MORFOLÓGICO DE CLONES DE Eucalyptus urograndis SUBMETIDOS A DIFERENTES NÍVEIS DE ÁGUA NO SOLO.  Maria Renata Rocha Pereira1; Antônio Evaldo Klar1; Magali Ribeiro da Silva2; Raquel Albuquerque de Souza2; Nara Rosseti Fonseca31Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP,  [email protected] Recursos Naturais, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP3Departamento de Melhoramento e Produção Vegetal, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP  1 RESUMO             Este estudo objetivou avaliar os efeitos do estresse hídrico, nas características fisiológicas de dois clones de Eucalyptus urograndis, 105 e 433. O experimento foi conduzido em casa de vegetação, na Faculdade de Ciências Agronômicas da UNESP, campus de Botucatu nos meses de março a julho de 2005. O manejo hídrico foi estabelecido com base em dois potenciais mínimos de água no solo (Yf): -0,03 MPa ou -1,5 MPa. Foram avaliados: resistência difusiva ao vapor d’aguados estômatos, transpiração, e potencial total de água das folhas(Yf) realizadas nesse dia, das 8:20 às 17 h no esmo dia coletaram-se a altura, diâmetro do colo, área foliar, massa seca aérea, massa seca radicular. Apenas a altura e matéria seca aérea foram maiores estatisticamente no clone 433, em relação ao 105.Tratamentos sem estresse hídrico tiveram maior desempenho em todas características estudadas, não havendo influência dos clones. A resistência estomática apresentou maiores valores nos tratamentos submetidos à deficiência hídrica, com mais intensidade no clone 433, tal como ocorreu com o potencial de água na folha. A transpiração foi maior no clone 105 tanto na comparação entre plantas estressadas como nas não estressadas. As temperaturas das folhas tiveram valores mais elevados no clone 433, no tratamento estressado. Assim, conclui-se que há um melhor desempenho das plantas mantidas a um potencial de água no solo de -0,03 MPa e  comprova-se a maior resistência ao estresse hídrico pelo clone 105. UNITERMOS: estresse hídrico, irrigação, eucalipto  PEREIRA, M.R.R.; KLAR, A.E.; SILVA, M.R.; ALBUQUERQUE, R.; FONSECA, N.R. MORPHOLOGYCAL AND PHYSIOLOGICAL BEHAVIOR OF CLONES FROM Eucalyptus urograndis  SUBMITTED TO DIFFERENT SOIL  WATER LEVELS  2 ABSTRACT The present study had as its objective the assessment of the possible effects of hydric stress on the growth, physiological characteristics of two different genetic materials from Eucalyptus urograndis. The experiment was carried out in a greenhouse at Faculdade de Ciências Agronômicas of UNESP, campus Botucatu from March to July, 2005. The hydric management was established based on the soil water potential. Two water levels were established, doing the evapotranspired water replacement by pot weighing. Two clones were used, Eucalyptus urograndis 105 and 433, being the first one more resistant to the hydric deficit and the 433 more sensitive to stress. The study was made from a 2X2 factorial (two levels of water x two genetic materials). For the hydric management, the plants were irrigated when they reached a soil water potential of -0.03 MPa or -1.5 MPa. The assessments made were: diffusive water vapor of stomato, transpiration, leaf temperature and leaf water potential. The physiological evaluations  throughout the day, in the end of the experiment. Treatments without hydric stress had a higher performance in all studied characteristics, but the clones had no influence. The stomatic resistance followed the potentials, showing higher values in the treatments submitted to hydric deficiency, more intensely for clone 433, being that this also happened with the leaf water potential. The transpiration also followed the leaf water potential and the stomatic resistance more intensely for clone 105 both comparing stressed plants and non-stressed plants. Consequently, the leaf temperatures had higher values for clone 433 on the stressed treatment. Thus, it can be concluded that there was a better performance in plants kept on a soil water potential of -0.03 MPa and a higher resistance to hydric stress for clone 105. KEYWORDS: hydric stress, irrigation, eucalyptus


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