scholarly journals Establishment in Treeshelters II: Effect of Shelter Color on Gas Exchange and Hardiness

HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1284-1287 ◽  
Author(s):  
Roger Kjelgren ◽  
David T. Montague ◽  
Larry A. Rupp

We investigated the microclimate, gas exchange, and growth of field-grown Norway maple (Acer platanoides L.) and green ash (Fraxinus pennsylvanica Marsh) trees nonsheltered, and in brown and white shelters. Shelter microclimate—air temperature (Ta), vapor pressure deficit (VPD), and radiation—and tree leaf area, growth in diameter, stomatal conductance (gs), and photosynthesis were measured during the first growing season after bare-root transplanting. Bark temperatures in midwinter were also measured. Treeshelter microclimate was greenhouse-like compared to ambient conditions, as shortwave radiation was lower, and midday Ta and relative humidity were higher. Although trees in shelters had greater shoot elongation and higher gs than trees grown without shelters, photosynthesis was not different. White shelters allowed 25% more shortwave radiation penetration and increased Ta by 2 to 4 °C and VPD by 0.5-1 kPa over brown shelters. However, tree growth and gas exchange generally were not affected by shelter color. Winter injury was increased for trees in shelters and varied with species and shelter color. Both species exhibited shoot dieback in shelters the spring following a winter where bark temperatures varied 40 to 50 °C diurnally. More new growth died on maple, particularly in white shelters where several trees were killed. These data suggest that supraoptimal summer and winter temperatures may reduce vigor and interfere with cold tolerance of some species grown in shelters.

HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1409d-1409
Author(s):  
David T. Montague ◽  
Roger Kjelgren ◽  
Larry Rupp

We investigated microclimate, gas exchange, and growth of field-grown Norway maple (Acer platanoides) and green ash (Fraxinus pennsylvanica) trees in brown, white, or no treeshelters. Microclimate, tree growth, and gas exchange measurements were taken summer and winter. Treeshelter microclimate was greenhouse-like compared to ambient conditions, as short-wave radiation (S↓) was lower, and midday air temperature and relative humidity were higher. In both species, this resulted in less trunk growth and greater specific leaf area, which are growth responses characteristic of shade acclimation. Treeshelter microclimate did, however, substantially increase shoot elongation and stomatal conductance, but did not increase photosynthesis when compared to trees grown without shelters. White shelters allowed 25% more penetration of S↓ than brown shelters, but tree growth and climatic variables did not differ with treeshelter color. Stomatal conductance, however, was higher for trees in white shelters. Treeshelters also appeared to have a negative effect on plant hardiness. New shoot growth in shelters was more winter-damaged, particularly in maple, than nonsheltered trees. This may be related to winter bark (Tb) and air temperature (Ta). Winter midday Tb on trees grown in shelters was up to 15C higher than Tb on trees outside shelters, while midday Ta inside treeshelters was up to 20C higher than Ta outside treeshelters.


2002 ◽  
Vol 20 (2) ◽  
pp. 96-100
Author(s):  
D.H. West ◽  
A.H. Chappelka ◽  
K.M. Tilt ◽  
H.G. Ponder ◽  
J.D. Williams

Abstract One-year-old seedlings of sawtooth oak, white oak, green ash and flowering dogwood were evaluated to determine the effect of tree shelters on survival, growth and gas exchange. Trees were grown under both field and container nursery conditions. Shelters had a significant impact on survival of field-grown trees, but not on containerized, nursery-grown seedlings. Overall survival was approximately 75 and 40% for sheltered and non-sheltered, field-grown trees, respectively. Sheltered plants had approximately a 90% survival rate and non-sheltered trees exhibited approximately 80% survival in a nursery situation. In the field, sheltered trees had greater height growth and biomass production than non-sheltered trees. However, sheltered plants exhibited a decrease in total biomass in the nursery study, the majority of which was reflected in an overall 62% reduction in root production in the sheltered trees. Photosynthesis of sheltered trees averaged 65% of non-sheltered trees and internal leaf CO2 was approximately 11% greater in sheltered trees. Shelters appear to benefit field-planted seedlings by providing physical protection and shade therefore, enabling the tree to better survive stresses from ambient conditions. In nursery situations, shelters may only be helpful in training attractive trees with less labor.


2009 ◽  
Vol 27 (4) ◽  
pp. 229-233 ◽  
Author(s):  
Gary W. Watson

Abstract Exposed fine roots are subject to desiccation, which may affect their survival as well as new root growth following bare root transplanting. Fine roots of dormant 1-year-old green ash (Fraxinus pennsylvanica) and sugar maple (Acer saccharum) seedlings, subjected to desiccation treatments of 0, 1, 2, or 3 hours in December and March, lost up to 82 percent of their water. Root electrolyte leakage, a measure of cell damage, tripled after three hours of desiccation. The increase was moderately, but significantly, greater in March for both species. Desiccation treatments had no effect on fine root survival. Growth of new roots (RGP) was also unaffected by desiccation treatments. RGP of maple was greater in March than December, but not ash.


2014 ◽  
Vol 32 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Lindsey Fox ◽  
Amber Bates ◽  
Thayne Montague

For three growing seasons (2003–2005) two newly planted, field-grown redbud (Cercis canadensis L.) varieties were subjected to three reference evapotranspiration (ETo)-based irrigation regimes (100, 66, and 33% ETo). Over this time period, water relations (pre-dawn leaf water potential), gas exchange (mid-day stomatal conductance), and growth data (trunk cross sectional area increase, tree leaf area, and shoot elongation) were measured. Pre-dawn leaf water potential (ψl) was more negative for trees receiving the least amount of irrigation, and for Mexican redbud [C. canadensis var. mexicana (Rose) M. Hopkins] trees. However, mid-day stomatal conductance (gs) was similar for Texas redbud (C. canadensis var. texensis S. Watson) trees across the three irrigation regimes, and was highest for Mexican redbud trees receiving the greatest amount of irrigation volume. Growth varied by variety and irrigation regime. Trunk cross sectional area increase was greatest for Mexican redbud trees, leaf area was highest for trees receiving the greatest amount of irrigation, and shoot elongation was greatest for trees receiving the 66% ETo irrigation regime. However, despite differing irrigation volumes, greatest gas exchange and growth was not necessarily associated with greatest irrigation volume. When considering conservation of precious water resources, these redbud varieties maintain adequate growth and appearance under reduced irrigation.


1994 ◽  
Vol 12 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Rick M. Bates ◽  
Alex X. Niemiera

Abstract Desiccation during storage and reestablishment is a major factor contributing to poor regrowth of transplanted bare-root trees. The effect of overhead mist irrigation on reducing post transplant water stress in Norway maple (Acer platanoides L. ‘Emerald Lustre’) and Yoshino cherry (Prunus x yedoensis) was examined. Bare-root Norway maple (desiccation tolerant) and Yoshino cherry (desiccation sensitive) trees were transplanted into pine bark-filled containers and subjected to mist or non-mist treatments. Stem xylem water potential, relative water content, and survivability were determined. Xylem water potential increased (became less negative) for misted maple and cherry trees. Water potential increased for non-misted maple and decreased for non-misted cherry trees. Twenty-seven percent of non-misted cherries were evaluated as nonmarketable due to stem dieback compared to 0% for misted trees. Results of this study indicate that mist irrigation effectively reduces desiccation damage for desiccation sensitive species such as cherries and hawthorns.


2017 ◽  
Vol 115 (5) ◽  
pp. 1004-1008 ◽  
Author(s):  
Yann Vitasse ◽  
Constant Signarbieux ◽  
Yongshuo H. Fu

One hundred years ago, Andrew D. Hopkins estimated the progressive delay in tree leaf-out with increasing latitude, longitude, and elevation, referred to as “Hopkins’ bioclimatic law.” What if global warming is altering this well-known law? Here, based on ∼20,000 observations of the leaf-out date of four common temperate tree species located in 128 sites at various elevations in the European Alps, we found that the elevation-induced phenological shift (EPS) has significantly declined from 34 d⋅1,000 m−1 conforming to Hopkins’ bioclimatic law in 1960, to 22 d⋅1,000 m−1 in 2016, i.e., −35%. The stronger phenological advance at higher elevations, responsible for the reduction in EPS, is most likely to be connected to stronger warming during late spring as well as to warmer winter temperatures. Indeed, under similar spring temperatures, we found that the EPS was substantially reduced in years when the previous winter was warmer. Our results provide empirical evidence for a declining EPS over the last six decades. Future climate warming may further reduce the EPS with consequences for the structure and function of mountain forest ecosystems, in particular through changes in plant–animal interactions, but the actual impact of such ongoing change is today largely unknown.


Author(s):  
Gerhard Wieser ◽  
Wilhelm M. Havranek

SynopsisLittle is known about ozone (O3) effects on adult trees in the field, where ecophysiological parameters control pollutant uptake. It was the goal of this study to examine how ambient and above ambient O3 concentrations affect gas exchange of mature Norway spruce (Picea abies (L.) Karst.). Therefore, twigs were enclosed in chambers and exposed to different O3 concentrations for one and two seasons over three years. During winter periods twigs were maintained under ambient conditions. Data from the shade crown of spruce trees at 1000 m a.s.l. are presented. After one and two fumigation periods no clear treatment effects on gas exchange were observed in twigs fumigated with O3 concentrations ranging from zero up to ambient (A) + 60 ppb. However, O3 at 90 ppb reduced photosynthesis and conductance. CO2 response curves indicated that in A + 90 twigs the efficiency of CO2 uptake was diminished. Observed losses in Pn of A + 90 twigs were greater than reductions in conductance indicating that stomatal closure alone did not limit CO2 uptake. We conclude that ambient and slightly above ambient O3 concentrations do not alter gas exchange of mature Norway spruce. Therefore, suppositions on O3 damage on mature spruce trees should be critically questioned.


1976 ◽  
Vol 40 (5) ◽  
pp. 827-831 ◽  
Author(s):  
J. A. McLean ◽  
P. R. Watts

An analysis is presented of a system for indirect calorimetric measurement. Emphasis has been placed upon problems associated with the use of large climate-controlled chambers. The dynamics of gas exchange and the influence of ambient conditions on various parameters have been subjected to physical analysis which has led to the following conclusions: 1) Fast-response measurement of heat production can be achieved even if the size and hence washout time of the chamber is large. 2) Accurate continuous measurement of heat production over long periods, without correction for changes in barometric pressure, is possible if suitable instrumentation is chosen. 3) A method for calibration of a paramagnetic oxygen analyzer achieved high accuracy at low cost. 4) The entire system has been checked by simulation of gas exchange in the chamber, by injection of nitrogen at a known rate.


2007 ◽  
Vol 7 ◽  
pp. 90-97 ◽  
Author(s):  
Nicla Contran ◽  
Elena Paoletti

We compared leaf visible injury and physiological responses (gas exchange and chlorophyll a fluorescence) to high O3exposure (150 nmol mol–1h, 8 h day–1, 35–40 days) of two woody species of the same genus with different ecological features: the mesophilic green ash (Fraxinus excelsior) and the xerotolerant manna ash (F. ornus). We also studied how provenances from northern (Piedmont) and central (Tuscany) Italy, within the two species, responded to O3exposure. Onset and extent of visible foliar injury suggested thatF. excelsiorwas more O3sensitive thanF. ornus. The higher stomatal conductance inF. ornusthan inF. excelsiorsuggested a larger potential O3uptake, in disagreement to lower visible foliar injury. The higher carbon assimilation inF. ornussuggested a higher potential of O3detoxification and/or repair. Contrasting geographical variations of ash sensitivity to O3were recorded, as Piedmont provenances reduced gas exchange less than Tuscan provenances inF. excelsiorand more inF. ornus. Visible injury was earlier and more severe inF. excelsiorfrom Piedmont than from Tuscany, while the provenance did not affect visible injury onset and extent inF. ornus.


2004 ◽  
Vol 44 (3) ◽  
pp. 353 ◽  
Author(s):  
R. S. Tegg ◽  
P. A. Lane

The increased use of semi and fully enclosed sports stadiums necessitates the ongoing selection, development and assessment of shade-tolerance in turfgrass species. Vertical shoot growth rate is a simple biological measure that may supplement visual turfgrass assessment and provide a useful measure of shade adaptation. Cool-season temperate turfgrasses; Kentucky bluegrass–perennial ryegrass (Poa pratensis L.–Lolium perenne L.), creeping bentgrass (Agrostis palustris Huds.), supina bluegrass (Poa supina Schrad.) and tall fescue (Festuca arundinacea Schreb.), and a warm season species, Bermudagrass (Cynodon dactylon L.), were established in pot and field experiments and subjected to 4 shade treatments (0, 26, 56 or 65% shade) under ambient conditions. Average light readings taken near the winter and summer solstice in full sunlight at midday, were 790 and 1980�μmol/m2.s, respectively. Field and pot trials confirmed supina bluegrass and tall fescue to have the greatest shade tolerance, producing high turf quality under 56 and 65% shade. However, all turfgrass species declined in quality under high shade levels as indicated by an increase in thin, succulent vertical growth, and a less-dense turf sward. Vertical shoot growth rates of all species increased linearly with increasing shade levels. Kentucky bluegrass–perennial ryegrass had the highest rate of increase in vertical shoot elongation under shade, approximately 3.5 times greater than supina bluegrass, which had the lowest. Low rates of increase in vertical shoot elongation under shade indicated shade tolerance whereas high rates inferred shade intolerance.


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