Reductions in gas exchange of Populustremuloides caused by leaf aging and ozone exposure

1996 ◽  
Vol 26 (8) ◽  
pp. 1384-1391 ◽  
Author(s):  
C. Scott Clark ◽  
E.H. Lee ◽  
J.A. Weber ◽  
W.E. Hogsett
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Physiological Activity ◽  
Ozone Exposure ◽  
Control Treatment ◽  
Carbon Gain ◽  
Quaking Aspen ◽  
Response Curves ◽  
Plant Variation ◽  
Highly Correlated

Declines in gas exchange of mature leaves of Populustremuloides Michx. (quaking aspen) seedlings under four O3 treatments were investigated in a 33-d study. Gas exchange fell gradually with time, but under O3 exposure declines were accelerated. Photosynthetic capacity, stomatal conductance, and carboxylation efficiency were highly correlated, suggesting a coordinated reduction in the physiological activity of stressed leaves. Intercellular CO2 was not significantly different among treatments, indicating that stomatal opening was not the primary factor in limiting photosynthesis. Analysis of A:Ci response curves revealed that stomatal limitation increased only slightly, while biochemical limitation more than doubled, reaching a maximum of 47.1% by the third week of fumigations. Number of surviving leaves, ratio of surviving leaves to leaves produced, and total leaf area declined with O3 exposure. Whole-plant response curves were less linear than curves for the oldest subset of leaves because new leaves were produced continuously during the study, resulting in within-plant variation in O3 exposure. Declines in photosynthesis were greater than leaf area losses when data were expressed as a percentage of the control treatment. These results indicate that exposure to O3 for a relatively short time severely limits plant carbon gain in a sensitive free-growing species like aspen.

Seasonal responses of leaf gas exchange to elevated carbon dioxide in Populusgrandidentata

1992 ◽  
Vol 22 (9) ◽  
pp. 1320-1325 ◽  
Author(s):  
Peter S. Curtis ◽  
James A. Teeri
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Partial Pressure ◽  
Leaf Area ◽  
Leaf Gas Exchange ◽  
Exposure Period ◽  
Initial Slope ◽  
Carbon Gain ◽  
Late Season ◽  
Leaf Weight

Rising atmospheric carbon dioxide concentrations may have important consequences for forest ecosystems. We studied above- and below-ground growth and leaf gas exchange responses of Populusgrandidentata Michx. to elevated CO2 under natural forest conditions over the course of a growing season. Recently emerged P. grandidentata seedlings were grown in native, nutrient-poor soils at ambient and twice ambient (707 μbar (1 bar = 100 kPa)) CO2 partial pressure for 70 days in open-top chambers in northern lower Michigan. Total leaf area and shoot and root dry weight all increased in high CO2 grown plants. Photosynthetic light and CO2 response characteristics were measured 28, 45, and 68 days after exposure to elevated CO2. In ambient grown plants, light saturated assimilation rates increased from day 28 to day 45 and then declined at day 68 (15 September). This late-season decline, typical of senescing Populus leaves, was due both to a decrease in the initial slope of the net CO2 assimilation versus intercellular CO2 partial pressure relationship and to decreased CO2 saturated assimilation rates. Specific leaf nitrogen (mg N•(cm2 leaf area)−1) did not change during this period, although leaf carbon content and leaf weight (mg•cm−2) both increased. In ambient grown plants stomatal conductance also declined at day 68. In contrast, plants grown at elevated CO2 showed no late-season decline in photosynthetic capacity or changes in leaf weight, suggesting a delay in senescence with long-term exposure to high CO2. High CO2 grown plants also maintained photosynthetic sensitivity to increasing Ci throughout the exposure period, while ambient CO2 grown plants were insensitive to Ci above 400 μbar on day 68. These results indicate the potential for direct CO2 fertilization of P. grandidentata in the field and provide evidence for a new mechanism by which elevated atmospheric CO2 could influence seasonal carbon gain.

Seedling growth in conifers and angiosperms: impacts of contrasting xylem structure

2005 ◽  
Vol 53 (8) ◽  
pp. 749 ◽  
Author(s):  
T. J. Brodribb ◽  
N. M. Holbrook ◽  
R. S. Hill
Keyword(s):  
Hydraulic Conductivity ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Area ◽  
Seedling Growth ◽  
Light Adaptation ◽  
Efficient Production ◽  
Xylem Structure ◽  
Highly Correlated ◽  
Global Vegetation

Competitive interaction between conifers and angiosperms has moulded the structure of global vegetation since the Cretaceous. Angiosperms appear to enjoy their greatest advantage in the lowland tropics, an advantage often attributed to the presence of vessels in their xylem tissue. By monitoring the seedling growth of three members of the pan-tropical conifer family Podocarpaceae and three tropical angiosperm tree species, our aim was to determine whether these conifer and angiosperm seedlings showed distinct patterns of growth and light adaptation that might be attributed to the presence/absence of vessels. Angiosperm seedlings were consistently more efficient in terms of leaf area carried per unit stem investment, as well as more responsive to light climate than the conifer seedlings. Apparently linked to this were larger growth rate, stem hydraulic conductivity and stomatal conductance in the angiosperm sample. Stem hydraulic conductivity and maximum stomatal conductance were highly correlated among species and light treatments explaining the association between highly conductive vessel-bearing wood and high rates of gas exchange. We conclude that xylem vessels contribute to higher rates of gas exchange and more efficient production of leaf area in our sample angiosperms than in conifers. However, this advantage is limited by shade.

Gas Exchange and Leaf Area Characteristics of Four Tall Fescue Selections Differing in Forage Yield 1

Crop Science ◽  
1982 ◽  
Vol 22 (4) ◽  
pp. 709-711 ◽  
Author(s):  
C. J. Cohen ◽  
D. O. Chilcote ◽  
R. V. Frakes
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Tall Fescue ◽  
Forage Yield

scholarly journals Leaf traits and gas exchange in saplings of native tree species in the Central Amazon

2010 ◽  
Vol 67 (6) ◽  
pp. 624-632 ◽  
Author(s):  
Keila Rego Mendes ◽  
Ricardo Antonio Marenco
Keyword(s):  
Gas Exchange ◽  
Nitrogen Content ◽  
Leaf Area ◽  
Tree Species ◽  
Leaf Traits ◽  
Leaf Nitrogen ◽  
Dry Season ◽  
Leaf Thickness ◽  
Rainfall Regime ◽  
Leaf Nitrogen Content

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (g s), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness).

scholarly journals Growth and gas exchange of corn under salt stress and nitrogen doses

2021 ◽  
Vol 25 (3) ◽  
pp. 174-181
Author(s):  
Henderson C. Sousa ◽  
Geocleber G. de Sousa ◽  
Carla I. N. Lessa ◽  
Antonio F. da S. Lima ◽  
Rute M. R. Ribeiro ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Area ◽  
Plant Height ◽  
Saline Water ◽  
Saline Stress ◽  
Low Salinity ◽  
Salinity Water ◽  
Hybrid Maize ◽  
The University

ABSTRACT The excess of salts can affect several processes in the crops, and nitrogen (N) can attenuate the depressive effect of salinity. The objective was to evaluate the influence of nitrogen doses on the growth and gas exchange of corn crop irrigated with saline water. The experiment was conducted from June to September 2019 at the University of International Integration of Afro-Brazilian Lusophony, Redenção, CE, Brazil. The experimental design was completely randomized, in a 2 x 3 factorial scheme (supply water of 0.3 dS m-1 and saline solution of 3.0 dS m-1) and three nitrogen doses, 0, 80, and 160 kg ha-1, corresponding to 0, 50, and 100% of the recommended dose respectively, with six repetitions. At 30 and 45 days after sowing (DAS), plant height, leaf area, number of leaves, photosynthesis, transpiration, and stomatal conductance were evaluated. Saline stress affects plant height, leaf area, photosynthesis, transpiration, and conductance at 30 DAS. The doses of 80 and 160 kg ha-1 provide greater performance in plant height, leaf area, photosynthesis, transpiration, and conductance at 30 DAS. The use of low salinity water and doses of 80 and 160 kg ha-1 were more efficient in terms of plant height, leaf area, photosynthesis, transpiration, and conductance at 45 DAS. The dose of 160 kg ha-1 of N attenuates the harmful effects of salts in AG 1051 hybrid maize plants, providing higher values of photosynthesis, transpiration, and stomatal conductance at 45 DAS when irrigated with water of 3.0 dS m-1.

scholarly journals Influence of Irrigation Regime on Water Relations, Gas Exchange, and Growth of Two Field-grown Redbud Varieties in a Semiarid Climate

2014 ◽  
Vol 32 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Lindsey Fox ◽  
Amber Bates ◽  
Thayne Montague
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Leaf Area ◽  
Shoot Elongation ◽  
Sectional Area ◽  
Irrigation Regime ◽  
Cross Sectional ◽  
Area Increase ◽  
Irrigation Volume

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.

scholarly journals Does insect herbivory suppress ecosystem productivity? Evidence from a temperate woodland

2021 ◽  
Author(s):  
Kristiina Visakorpi ◽  
Sofia Gripenberg ◽  
Yadvinder Malhi ◽  
Terhi Riutta
Keyword(s):  
Gas Exchange ◽  
Leaf Area ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Leaf Gas Exchange ◽  
Insect Herbivory ◽  
Ecosystem Productivity ◽  
Area Loss ◽  
Leaf Area Loss ◽  
The Relationship

AbstractOur current understanding of the relationship between insect herbivory and ecosystem productivity is limited. Previous studies have typically quantified only leaf area loss, or have been conducted during outbreak years. These set-ups often ignore the physiological changes taking place in the remaining plant tissue after insect attack, or may not represent typical, non-outbreak herbivore densities. Here, we estimate the amount of carbon lost to insect herbivory in a temperate deciduous woodland both through leaf area loss and, notably, through changes in leaf gas exchange in non-consumed leaves under non-outbreak densities of insects. We calculate how net primary productivity changes with decreasing and increasing levels of herbivory, and estimate what proportion of the carbon involved in the leaf area loss is transferred further in the food web. We estimate that the net primary productivity of an oak stand under ambient levels of herbivory is 54 - 69% lower than that of a completely intact stand. The effect of herbivory quantified only as leaf area loss (0.1 Mg C ha−1 yr−1) is considerably smaller than when the effects of herbivory on leaf physiology are included (8.5 Mg C ha−1 yr−1). We propose that the effect of herbivory on primary productivity is non-linear and mainly determined by changes in leaf gas exchange. We call for replicated studies in other systems to validate the relationship between insect herbivory and ecosystem productivity described here.

scholarly journals LEAF GAS EXCHANGE IN TWO DWARF COCONUT GENOTYPES IN THE SOUTHEAST OF BAHIA STATE, BRAZIL.

CORD ◽  
2002 ◽  
Vol 18 (02) ◽  
pp. 34
Author(s):  
Gomes, F.P. ◽  
Mielke, M.S. ◽  
Almeida, A. F. ◽  
Muniz, W. S.
Keyword(s):  
Gas Exchange ◽  
Water Vapour ◽  
Leaf Gas Exchange ◽  
Cocos Nucifera ◽  
Vapour Pressure Deficit ◽  
Light Response ◽  
Negative Influence ◽  
Water Vapour Pressure ◽  
Response Curves ◽  
Palm Trees

Net photosynthetic (A) and leaf transpiration (E) rates and stomatal conductance to water vapour (gs) of Malayan Yellow Dwarf (MYD) and Brazilian Green Dwarf (BGD) coconut accessions (Cocos nucifera var. ‘nana’ L.) were studied and discussed in terms of the technical aspects related to light-response curves in field conditions. Measurements of gas exchange were performed during four days, in April and may 2000, at the Cocoa Research Center Experimental Station (Una - BA, Brazil). The A, gs and E parameters were significantly (P < 0.05) different between the two genotypes. The mean maximum values of A, gs and E were 10.4 and 12.0 µmol CO2 m-2 s-1, 0.21 and 0.35 mol H2O m-2 s-1 and 3.07 and 3.69 mmol m-2 s-1 for MYD and BGD, respectively. For both genotypes a good fitting of the light-response curve models were obtained, indicating that A and gs were dependent of the photosynthetically active radiation incident on leaf surface (Qi), in spite of high genotipic variation. Interesting results were achieved when an empirical multiplicative model was used. The model relating A or gs with Qi and with leaf-to-air water vapour pressure deficit inside the chamber (VPDL) was tested for both genotypes and showed a negative influence of the latter on the stomatal behavior and consequently on A. Such effect was more pronounced in BGD than in MYD. These and others relationships involving leaf gas exchange and microclimatic variables in coconut palm trees are discussed

scholarly journals Response of Three Varieties of Cowpea( Vigna sinensis L.) to Different levels of potassium fertilizer under southern region conditions of Iraq

2019 ◽  
Vol 32 ◽  
pp. 25-34
Author(s):  
Ali. K. Al-Furtuse ◽  
Kifah A. Aldoghachi ◽  
Waleed A. Jabail
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Block Design ◽  
Growth And Yield ◽  
Control Treatment ◽  
Potassium Fertilizer ◽  
Vigna Sinensis ◽  
Highest Weight ◽  
Different Levels ◽  
Plant Length

A field experiment was conducted during  autumn season 2018 at Al Salam district, Maysan governorate. The aim was to evaluate some growth properties and grain yield of  three varieties of cowpea, Vigna sinensis L. (Local, Patton Boa and Atta E) grown under different levels of potassium sulphate  (0, 43, 86 and 129 kg h-1). The  experimental  design was applied according to the random complete block design in a split arrangement (Split Plots in RCBD). In on hand, the results showed a significant differences between the varieties. The local variety significantly gave highest plant length , leaf area, pods number, seeds number pod-1 and grain yield and which were 60.75cm, 2936.81cm2, 39.60 pod. plant-1, 7.69 seed pod-1, 99.93 g and 4.16 t. h-1 respectively. While the varieties Baton Boa gave highest weight of 100 seeds and gave 37.58 g. In other hand, as compare to the control, the addition of potassium up to 129 kg. h-1 lead to significant increase in plant length, leaf area, pods plant-1, seeds number pod-1 and grain yield plant-1 and total grain yield which were 53.33 cm, 3455.91 cm2, 51.61 pod. plant-1, 8.76 seed. pod-1, 125.93 g. and 5.25 T.h-1 respectively. Whereas, the control treatment (K0) gave the highest weight of 100 seeds (45.11 g). The Interaction between varieties and potassium  had a significant effect on almost  growth and yield characteristics.

Sign in / Sign up

Export Citation Format

Share Document