Photosynthesis and Water Relations During Drought in Acer rubrum L. Genotypes from Contrasting Sites in Central Pennsylvania

1990 ◽  
Vol 4 (6) ◽  
pp. 727 ◽  
Author(s):  
M. D. Abrams ◽  
M. E. Kubiske
Keyword(s):  
Water Relations ◽  
Acer Rubrum ◽  
Central Pennsylvania

scholarly journals Water Relations of Acer rubrum in Response to Summer Digging

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 595C-595
Author(s):  
P.R. Knight ◽  
J.R. Harris ◽  
J.K. Fanelli ◽  
M.P. Kelting
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Water Relations ◽  
Leaf Water Potential ◽  
Sap Flow ◽  
Acer Rubrum ◽  
Leaf Water ◽  
Xylem Embolism ◽  
Ball Diameter ◽  
Old Trees

Two experiments were conducted on Acer rubrum L. to determine the influence of root severance on sap flow, stomatal conductance, leaf water potential (ψ), and stem xylem embolism. Experiment 1 utilized 3-year-old trees, and experiment 2 utilized 2-year-old trees. Sixteenmm sap flow gauges were installed on both groups. Trees for experiment 1 were harvested on 31 May 1996 with a root ball diameter of 30.5 cm. Sap flow was reduced within one day after plants were harvested and was still lower 1 week after harvest. On 7 June 1996, harvested trees had lower stomatal conductance measurements, compared to not-harvested trees, but ψ were similar. A second experiment was initiated on 20 Aug. 1996, using the same protocol as in experiment 1. Sap flow was reduced within 2 h after harvest for harvested trees compared to not-harvested trees. Leaf stomatal conductances were reduced within 4 h of harvest. Leaf water potentials were not influenced on the day that the trees were harvested. Embolism levels were increased by harvest within 24 h. These results indicate that transplant stress begins shortly after harvest and not at the actual time of transplant.

scholarly journals Drought and Flood Stress Effects on Plant Development and Leaf Water Relations of Five Taxa of Trees Native to Bottomland Habitats

1993 ◽  
Vol 118 (6) ◽  
pp. 845-850 ◽  
Author(s):  
Lenore J. Nash ◽  
William R. Graves
Keyword(s):  
Water Relations ◽  
Root Zone ◽  
Acer Rubrum ◽  
Dry Mass ◽  
Urban Environments ◽  
Leaf Water ◽  
Red Maple ◽  
Leaf Water Relations ◽  
Bald Cypress ◽  
Drought And Flood

Responses of five bottomland tree taxa to drought and flooding were studied to identify those adapted to urban environments. During one experiment, containerized `Franksred' red maple [Acer rubrum L. `Franksred' (trademark = Red Sunset)], sweetbay magnolia (Magnolia virginiana L.), black tupelo (Nyssa sylvatica Marsh.), bald cypress [Taxodium distichum (L.) Rich.], and pawpaw [Asimina triloba (L.) Dunal.] were treated with various irrigation regimes for up to 118 days. Net assimilation rate (NAR) and relative growth rate (RGR) were reduced more by flooding than by drought for plants of all taxa, except pawpaw, which showed similar NAR and RGR during flooding and drought. Only sweetbay magnolia and bald cypress maintained positive NAR and RGR during flooding, and sweetbay magnolia was the only taxon that did not produce significantly less leaf surface area, shoot dry mass, and root dry mass during flooding and drought. Apparent morphological mechanisms of stress resistance included an increase in specific mass of leaves (mg·cm-2) during drought for red maple and bald cypress and a 385% increase in the root: shoot mass ratio for droughted plants of pawpaw. Leaf water relations of drought- and flood-stressed `Franksred' red maple and sweetbay magnolia were determined in a second experiment. Predawn and mid-day leaf water potential (ψ) decreased with decreasing root-zone matric potential for both taxa, and transpiration rate was reduced by drought and flooding. Pressure-volume analysis showed that leaves of `Franksred' red maple responded to drought by shifting symplastic water to the apoplast. Leaves of drought-stressed sweetbay magnolia adjusted osmotically by reducing osmotic potential (ψπ) at full turgor by 0.26 MPa. Our results suggest that sweetbay magnolia and bald cypress will perform well at urban planting sites where episodes of drought and flooding regularly occur.

Photosynthesis, water relations, and leaf morphology of xeric versus mesic Quercusrubra ecotypes in central Pennsylvania in relation to moisture stress

1992 ◽  
Vol 22 (9) ◽  
pp. 1402-1407 ◽  
Author(s):  
Mark E. Kubiske ◽  
Marc D. Abrams
Keyword(s):  
Water Relations ◽  
Leaf Morphology ◽  
Photosynthetic Apparatus ◽  
Morphological Characteristics ◽  
Net Photosynthesis ◽  
Moisture Stress ◽  
Tissue Water ◽  
Central Pennsylvania ◽  
Relative Water ◽  
Mesic Site

Differences in photosynthesis and water relations during drought, and in leaf morphology, were evaluated in 1-year-old greenhouse-grown Quercusrubra L. seedlings from neighboring mesic and xeric sites in central Pennsylvania, U.S.A. Xeric seedlings had higher photosynthetic rates and stomatal conductance to water vapor than mesic seedlings during well-watered conditions. During a drought cycle, xeric seedlings maintained positive net photosynthesis at significantly lower predawn leaf water potential and relative water content. Mesic seedlings exhibited greater intrasource variation in gas exchange during drought, which may be related to reduced selection pressure for drought tolerance characteristics on the mesic site or to gene flow from the adjacent, upslope xeric site. Nonstomatal limitations to photosynthesis increased during drought and accounted for 98% of the reduction in photosynthesis as both sources approached incipient wilting. Xeric seedlings exhibited less nonstomatal inhibition of photosynthesis during early and midstages of drought, suggesting a greater tolerance of the photosynthetic apparatus for tissue water deficit. Xeric seedlings also exhibited the expected leaf morphological characteristics, which included smaller leaf area and greater leaf thickness and specific leaf mass. These results indicate that Q. rubra growing on adjacent sites in central Pennsylvania exhibit ecotypic differences in ecophysiology that are consistent with site moisture conditions.

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