Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. ex Spreng. VI. Comparison of Field and Phytotron Responses to Growth Temperature

1977 ◽  
Vol 4 (6) ◽  
pp. 901 ◽  
Author(s):  
RO Slayter
Keyword(s):  
Growth Temperature ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Equivalent Temperature ◽  
Temperature Optimum ◽  
Response Curves ◽  
Preferred Temperature ◽  
Practical Applications ◽  
Field Temperature ◽  
Temperature Optima

A procedure for estimating field photosynthetic temperature optima from phytotron temperature response data, for elevational populations of E. pauciflora, is developed. It utilizes the principle that each population has a preferred temperature, Tpref, and an acclimation coefficient, α, which can be determined from phytotron-derived temperature response curves, and which enable the photosynthetic temperature optimum observed in a particular field temperature regime (Test) to be estimated from the expression Test = Tpref - α(Tpref - Tequiv), where Tequiv is a field temperature equivalent, in terms of its effect on the photosynthetic temperature optimum, to a known phytotron growth temperature. Application of the procedure to sets of field and greenhouse data suggests that when Tpref and α are based on phytotron day growth temperatures, and when Tequiv is based on the proposition that a square-wave conversion of the field day-time temperature curve is equivalent to the phytotron day growth temperature, estimates of field and greenhouse temperature optima can be made which give good agreement with observed values. The agreement is best when active, current-year tissue is used as a basis of the field observations and when single leaves rather than shoots are used for field measurements. The procedure is also used to compare actual rates of net photosynthesis, Pamb, obtained from field and phytotron studies, when both are plotted against equivalent temperature. Using this procedure, the large apparent differences between rates of net photosynthesis observed in the field and in the phytotron can be considerably reduced. This suggests that the notion of equivalent temperature may provide a useful means of minimizing the effects of physical, temperature-related differences in comparing field and phytotron responses, thereby widening the range of practical applications of phytotron experiments.

Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. ex Spreng. IV. Temperature Response of Four Populations Grown at Different Temperatures

1977 ◽  
Vol 4 (4) ◽  
pp. 583 ◽  
Author(s):  
RO Slayter
Keyword(s):  
Field Study ◽  
Growth Temperature ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Tree Line ◽  
Temperature Optimum ◽  
Response Curves ◽  
Preferred Temperature ◽  
Co2 Compensation Point ◽  
Preferred Temperatures

Photosynthetic temperature response curves were measured at leaf temperatures from 10 to 40°C on seedlings of E. pauciflora grown from seed collected at tree-line (elevation 1905 m) in the Snowy Mountains area and at three lower elevations, 915, 1215 and 1645 m, which correspond to those used in an earlier field study (Slatyer and Morrow 1977). The material was grown in naturally lit, temperature-controlled greenhouses at day/night temperatures of 8/4, 15/10, 21/16, 27/22 and 33/28°C. Comprehensive measurements were made on the tree-line population, in which peak rates of net photosynthesis, Pamb, reached 75 ng cm-2 s-1 at a temperature of 20�°C, from material grown at 21/16°. Minimum levels of intracellular resistance, rt, were 2.8 s cm-1, and of leaf gas-phase resistance to CO2 transfer, r1, were 3.2 s cm-1. Changes in rt and r1, with measurement temperature, appeared to be of approximately equal importance in mediating the overall photosynthetic temperature response. Changes in the CO2 compensation point, Γ were of increasing importance at higher measurement temperatures. The photosynthetic temperature optimum was markedly affected by the growth temperature regime. In the tree-line population, it increased from about 16° when grown at 8/4° to 24° when grown at 33/28°. The relationship between the observed photosynthetic temperature optimum and the day temperature of the growth regime indicated a preferred temperature for photosynthesis of 20.0°, and a tendency for the temperature optimum to shift by 0.34° per degree shift in the day growth temperature. A similar effect of growth temperature on the photosynthetic temperature optimum was noted in the three lower-elevation populations, in which preferred temperatures of 21.5, 24.2 and 27.2° were calculated for the material collected at 1645, 1215 and 915 m respectively. These temperatures were several degrees higher than the field-observed temperature optima, although the gradient of preferred temperature with elevation was comparable to that noted in the field study.

Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. Ex Spreng. III. Temperature Response of Material Grown in Contrasting Thermal Environments

1977 ◽  
Vol 4 (2) ◽  
pp. 301 ◽  
Author(s):  
RO Slatyer
Keyword(s):  
Growth Temperature ◽  
Strong Dependence ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
High Elevation ◽  
Similar Response ◽  
Site Location ◽  
Temperature Optimum ◽  
Response Curves ◽  
Thermal Environments

Photosynthetic temperature response curves were measured on seedlings of E. pauciflora grown from seed collected at high (1770 m) and low (915 m) elevation sites, in the Snowy Mountains. The material was grown in contrasting day/night temperature regimes (33/28 and 15/10°C) in the Canberra phytotron. The material from the high elevation site showed a temperature optimum at about 20°C when grown at 15/10°C and at about 25°C when grown at 33/28°C. By comparison, the temperature optimum for the low elevation material was near 25° when grown at 15/10°C and shifted to about 30° when grown at 33/28°C. The general form of the temperature response curves was similar for both sets of material, although net photosynthesis of the higher elevation material dropped off more rapidly at temperatures above and below the optimum. When grown at 15/10�C, peak Ievels of net photosynthesis were higher in the high elevation material (66 ng cm-2 s-1 v. 54 ng cm-2 s-1). When grown at 33/28°C, peak levels were higher in the low elevation material (78 ng cm-2 s-1 v. 60 ng cm-2 s-1). Similar response patterns were observed in intracellular resistance, ri, and gas phase resistance, ri, although there was relatively more change in ri, and relatively less change in ri, with respect to growth temperature and material, than in net photosynthesis. The most conservative parameter that was measured was the CO2 compensation point, Γ. Although it showed a strong dependence on measurement temperature, Γ was not significantly influenced by growth temperature or site location at the levels of probability used.

Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. Ex Spreng. VII. Relationship Between Gradients of Field Temperature and Photosynthetic Temperature Optima in the Snowy Mountains Area

1978 ◽  
Vol 26 (1) ◽  
pp. 111 ◽  
Author(s):  
RO Slatyer
Keyword(s):  
Close Agreement ◽  
Temperature Response ◽  
Lapse Rate ◽  
Maximum Temperature ◽  
Temperature Function ◽  
Preferred Temperature ◽  
Field Temperature ◽  
Effective Selection ◽  
Wave Conversion ◽  
Temperature Optima

Elevational gradients of several field temperature parameters were examined and compared with estimated and observed photosynthetic temperature optima for a range of elevational populations of E. pauciflora. The gradient of maximum temperature (9.68°km-1) was found to be very close to the dry adiabatic lapse rate, regardless of whether annual, seasonal or monthly conditions were examined. In contrast, the gradient of minimum temperature (2.06°km-1) was much flatter and was affected by topographic location, particularly at sites exposed to nocturnal temperature inversions. The gradient of the square-wave conversion of the day-time temperature curve (Tsqw), found previously to be useful in mediating the photosynthetic temperature response, was intermediate in slope, 7.20°km-1. The gradient of the phytotron-derived preferred temperature for photosynthesis, Tpref (6.26°km-1), was very close to that for Tsqw. The acclimation coefficient, α, showed no apparent change with elevation. Estimates of field photosynthetic temperature optima, based on Tpref, α and Tequiv (which was the value of Tsqw averaged for 10 days prior to the date of measurement) were in close agreement with measured values. The close agreement between the gradients of Tpref and Tsqw, together with the effectiveness of estimation of field temperature optima by means of Tequiv suggested that a temperature function resembling Tsqw may exert effective selection pressure on the photosynthetic temperature response of E. pauciflora in this environment.

Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. Ex Spreng. II. Effects of Growth Temperature Under Controlled Conditions

1977 ◽  
Vol 4 (2) ◽  
pp. 289 ◽  
Author(s):  
RO Slatyer ◽  
PJ Ferrar
Keyword(s):  
Gas Phase ◽  
Growth Temperature ◽  
Physiological Responses ◽  
Woody Species ◽  
Net Photosynthesis ◽  
Photosynthetic Characteristics ◽  
Temperature Optimum ◽  
Altitudinal Variation ◽  
Intracellular Resistance ◽  
Photosynthetic Responses

The photosynthetic responses of three altitudinal populations of snow gum, E. pauciflora Sieb. ex Spreng., were examined on material grown at a range of day/night temperatures from 8/4 to 33/28°C. The pattern of the photosynthetic responses to growth temperature was generally similar for all populations but the material from the lowest-elevation, warmest, site showed the highest temperature optimum and significantly higher rates of net photosynthesis at the highest growth temperature. In a corresponding way, the material from the highest-elevation, coldest, site showed the lowest temperature optimum, and significantly higher rates of net photosynthesis at the lowest growth temperature. This pattern, also reflected in the responses of rI, the intracellular resistance, and rI, the gas-phase resistance, supported the view that E. pauciflora shows continuous variation in physiological responses through its altitudinal range. The peak values of net photosynthesis were high for all populations, but were greatest, 81 ng cm-2 s-1, in the lowest elevation material and decreased to 72 ng cm-2 s-1 in the highest-elevation material. Corresponding values of rI ranged from 2.5 - 3.0 s cm-1, and for rI from 2.4 - 3.3 s cm-1. These levels compare favourably with levels reported for other woody species.

Temperature Response of Whole-plant CO2 Exchange Rates of Magnolia (Magnolia grandiflora L.)

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 511d-511
Author(s):  
Marc W. van Iersel ◽  
Orville M. Lindstrom
Keyword(s):  
Dark Respiration ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Co2 Exchange ◽  
Limiting Factor ◽  
Response Curves ◽  
Gross Photosynthesis ◽  
Temperature Range ◽  
Whole Plant ◽  
Increasing Temperature

Photosynthesis and respiration temperature-response curves are useful in predicting the ability of plants to perform under different environmental conditions. Whole crop CO2 exchange of two groups of magnolia `Greenback' plants was measured over a 26 °C temperature range. Net photosynthesis (Pnet) increased from 2 to 17% C and decreased again at higher temperatures. The Q10 for Pnet decreased from ≈4 at 6 °C to 0.5 at 24 °C. The decrease in Pnet at temperatures over 17 °C was caused by a rapid increase in dark respiration (Rdark) with increasing temperature. The Q10 for Rdark was estimated by fitting an exponential curve to data, resulting in a temperature-independent Q10 of 2.8. Gross photosynthesis (Pgross), estimated as the sum of Rdark and Pnet, increased over the entire temperature range (up to 25 °C). The Q10 for Pgross decreased with increasing temperature, but remained higher than 1. The data suggest that high respiration rates may be the limiting factor for growth of magnolia exposed to high temperatures, since it may result in a net carbon loss from the plants. At temperatures below 5 °C, both Pnet and Rdark become low and the net CO2 exchange of the plants would be expected to be minimal.

Photosynthetic light and temperature responses of Eucalyptus cloeziana and Eucalyptus argophloia

2003 ◽  
Vol 51 (5) ◽  
pp. 573 ◽  
Author(s):  
Michael R. Ngugi ◽  
Mark A. Hunt ◽  
David Doley ◽  
Paul Ryan ◽  
Peter J. Dart
Keyword(s):  
Quantum Yield ◽  
Dark Respiration ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Response Curves ◽  
Growth Environment ◽  
Eucalyptus Cloeziana

Acclimation of gas exchange to temperature and light was determined in 18-month-old plants of humid coastal (Gympie) and dry inland (Hungry Hills) provenances of Eucalyptus cloeziana F.Muell., and in those of a dry inland provenance of Eucalyptus argophloia Blakely. Plants were acclimated at day/night temperatures of 18/13, 23/18, 28/23 and 33/28�C in controlled-temperature glasshouses for 4 months. Light and temperature response curves were measured at the beginning and end of the acclimation period. There were no significant differences in the shape and quantum-yield parameters among provenances at 23, 28 and 33�C day temperatures. Quantum yield [μmol CO2 μmol–1 photosynthetic photon flux density (PPFD)] ranged from 0.04 to 0.06 and the light response shape parameter ranged from 0.53 to 0.78. Similarly, no consistent trends in the rate of dark respiration for plants of each provenance were identified at the four growth temperatures. Average values of dark respiration for the plants of the three provenances ranged from 0.61 to 1.86 μmol m–2 s–1. The optimum temperatures for net photosynthesis increased from 23 to 32�C for the humid- and from 25 to 33�C for the dry-provenance E. cloeziana and from 21 to 33�C for E. argophloia as daytime temperature of the growth environment increased from 18 to 33�C. These results have implications in predicting survival and productivity of E. cloeziana and E. argophloia in areas outside their natural distribution.

scholarly journals (112) Heat and Drought Affect Photosynthesis of Sugar Maple (Acer saccharum) Ecotypes

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1079A-1079
Author(s):  
Jason J. Griffin
Keyword(s):  
Water Potential ◽  
Great Plains ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Field Studies ◽  
Response Curves ◽  
Original Weight ◽  
Prolonged Drought

Common sugar maple (Acer saccharum Marshall) selections suffer from prolonged drought and constant wind on the southern Great Plains. Nonirrigated plants often have scorched and torn leaves as a result of these environmental stresses. In field studies, a sugar maple ecotype native to western Oklahoma (known as `Caddo' maple) has shown improved tolerance to drought and leaf tatter. A study to examine drought tolerance of seedling `Caddo' maple compared to typical seedling sugar maple was established at the John C. Pair Horticultural Center. One seedling of each type was planted in a single 38-L container. Containers were placed on a greenhouse bench, and once acclimated, irrigation was withheld until predawn leaf water potential indicated a substrate water potential of –1.5 MPa. Containers were weighed, and seedlings were maintained in a prolonged drought condition for 3 weeks by adding water each morning to return the container to the original weight. After 3 weeks, photosynthetic temperature response curves were generated for the drought-stressed and the irrigated control plants. Osmotic potential of expressed sap was also measured on rehydrated leaves. The main effects of species, irrigation, and temperature were all significant. `Caddo' maples were able to maintain a higher rate of net photosynthesis than the typical seedlings when drought stressed and as temperature increased. The optimum temperature for photosynthesis did not significantly differ among treatments (36 °C), whereas the maximum rate of photosynthesis was significantly greater for the `Caddo' maples (41 μmol·m-2·s-1) than the typical sugar maples (16 μmol·m-2·s-1).

Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. ex Spreng. V. Rate of Acclimation to an Altered Growth Environment

1977 ◽  
Vol 4 (4) ◽  
pp. 595 ◽  
Author(s):  
RO Slayter ◽  
PJ Ferrar
Keyword(s):  
Control Level ◽  
High Elevation ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Temperature Optimum ◽  
Preferred Temperature ◽  
Growth Environment ◽  
Temperature Optima ◽  
Maximum Minimum

Established, field-grown, seedlings of Eucalyptus pauciflora were transferred from high- and low- elevation field sites to a controlled-environment greenhouse in Canberra (maximum/minimum daily temperature range 26/15°) and the pattern of photosynthetic acclimation observed. Levels of net photosynthesis, Pamb, intracellular resistance rI, and leaf gas-phase resistance to CO2 transfer (r1) were monitored, as were the temperature optima for these parameters. Acclimation proceeded most rapidly in the material grown at the warmer, low-elevation, site (955 m), and in the low-elevation population. Daily maximum/minimum temperatures at this site for the 10 days prior to transfer averaged 23/11°. With this material, levels of, and the temperature optimum for, Pamb reached control levels within 6 days of transfer from the field environment. By comparison, Pamb in the high-elevation population grown at the high-elevation (tree-line) site (1910 m) where the 10-day temperature averaged 15/7°, did not reach control levels until 14 days after transfer, and the temperature optimum for Pamb required 20 days to reach the control level. In general, the patterns of change in rI and r1 paralleled those in Pamb. Both the level of physiological activity in the field, and the temperature differences between the field and greenhouse environment, appeared to affect the rate of acclimation. Immediately after transfer from the field, the temperature optima of the high-and low-elevation populations were close to the daily maximum temperature of the respective field environments. The temperature optimum of the high-elevation material grown at the low-elevation site was intermediate in value. At the conclusion of the acclimation period, the temperature optima of both high-elevation populations had converged to a value similar to that of the high-elevation control (about 22°); similarly, the temperature optimum of the low-elevation populations had reached the level of the low-elevation control (27°) These various temperature optima are interpreted on the basis that each population has a 'preferred' temperature which can be modified by different effective growth temperatures to yield different optima in different thermal environments. In the field, the effective temperature appears to be intermediate between the prevailing maximum and minimum temperatures.

scholarly journals Occurrence data may provide unreliable thermal preferences and breadth of species

2015 ◽  
Vol 61 (6) ◽  
pp. 972-982 ◽  
Author(s):  
Sara Villén-Pérez ◽  
Luis M. Carrascal
Keyword(s):  
Species Abundance ◽  
Bird Species ◽  
Temperature Response ◽  
Accurate Information ◽  
Classical Approach ◽  
Response Curves ◽  
Preferred Temperature ◽  
Average Temperature ◽  
Occurrence Data ◽  
Thermal Preferences

Abstract Accurate information on the thermal preference and specialization of species is needed to understand and predict species geographical range size and vulnerability to climate change. Here we estimate the position and breadth of species within thermal gradients based on the shape of the response curve of species abundance to temperature. The objective of the study is to compare the measurements of this approach based on abundance data with those of the classical approach using species’ occurrence data. The relationship between species’ relative abundance and minimum winter temperature of 106 bird species wintering in the Iberian Peninsula is modeled at 100 Km2 resolution with quadratic logistic regressions. From these models we calculated the preferred temperature of species as the temperature at which the abundance is maximized, and the thermal breadth of species as the relative area under the temperature-abundance curve. We also estimated the thermal preferences and breadth of species as the average temperature and temperature range of the UTM cells in which the species are present. The abundance-temperature response curves reveal that birds prefer higher temperatures to overwinter, and are more thermally selective, than is measured by the classical approach. Moreover, response curves detect a higher inter-specific variability in both thermal preferences and thermal breadth of species. As occurrence data gives the same weight to cells with one or many individuals, the average temperature of the cells in which the species is present roughly reflects the average temperature in the region of study and not the environmental preferences of species.

scholarly journals Heat Tolerance of Selected Species and Populations of Rhododendron

1995 ◽  
Vol 120 (3) ◽  
pp. 423-428 ◽  
Author(s):  
Thomas G. Ranney ◽  
Frank A. Blazich ◽  
Stuart L. Warren
Keyword(s):  
Heat Tolerance ◽  
Leaf Surface ◽  
Dark Respiration ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Tissue Weight ◽  
Unit Leaf ◽  
Leaf Surface Area ◽  
Temperature Optima ◽  
Two Populations

Temperature sensitivity of net photosynthesis (PN) was evaluated among four taxa of rhododendron including Rhododendron hyperythrum Hayata, R. russatum Balf. & Forr., and plants from two populations (northern and southern provenances) of R. catawbiense Michx. Measurements were conducted on leaves at temperatures rauging from 15 to 40C. Temperature optima for PN ranged from a low of 20C for R. russatum to a high of 25C for R. hyperythrum. At 40C, PN rates for R. hyperythrum, R. catawbiense (northern provenance), R. catawbiense (southern provenance), and R. russatum were 7.8,5.7,3.5, and 0.2 μmol·m-2·s-1, respectively (LSD0.05 = 1.7). Rhododendron catawbiense from the southern provenance did not appear to have greater heat tolerance than plants from the northern provenance. Differences in dark respiration among taxa were related primarily to differences in tissue weight per unit leaf surface area. Temperature coefficients (Q5) for respiration did not vary in temperature response among taxa. Differences in heat tolerance appeared to result from a combination of stomatal and nonstomatal limitations on PN at high temperatures.

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