Gas exchange characteristics of bald cypress (Taxodiumdistichum L.): evaluation of responses to leaf aging, flooding, and salinity

1986 ◽  
Vol 16 (6) ◽  
pp. 1394-1397 ◽  
Author(s):  
S. R. Pezeshki ◽  
R. D. DeLaune ◽  
W. H. Patrick Jr.
Keyword(s):  
Stomatal Conductance ◽  
Saline Water ◽  
Salt Water ◽  
Net Photosynthesis ◽  
Salt Water Intrusion ◽  
Low Salinity ◽  
Bald Cypress ◽  
Leaf Aging ◽  
Before And After ◽  
Gas Exchange Characteristics

Bald cypress (Taxodiumdistichum L.) seedlings were subjected to flooding with saline water containing 0 to 8 parts per thousand (137 mequiv. L−1 NaCl) under controlled environment conditions. Imposition of flooding and salinity stresses was designed to simulate the increase in submergence and salinity level which Louisiana's extensive cypress forests are currently experiencing as a result of rapid subsidence. The effect of flooding and salt water intrusion on subsequent stomatal behaviour and net photosynthesis for leaves developed before and after salt exposure were measured. Flooding and salinity resulted in a substantial decrease in stomatal conductance and net photosynthesis in both young and old leaves. Leaf aging did not significantly affect stomatal conductance and photosynthesis. Only plants flooded with freshwater and those flooded with low salinity concentration produced new leaves with improved stomatal conductance and net photosynthesis, which suggests some stomatal and photosynthetic acclimation to flooding and low salinity for bald cypress. Increase in salinity, however, caused more extensive impact and greater reductions of stomatal conductance and net photosynthesis in both leaf ages.

Effect of soil salinity on stomatal conductance and photosynthesis of green ash (Fraxinuspennsylvanica)

1986 ◽  
Vol 16 (3) ◽  
pp. 569-573 ◽  
Author(s):  
S. R. Pezeshki ◽  
J. L. Chambers
Keyword(s):  
Stomatal Conductance ◽  
Soil Salinity ◽  
Saline Water ◽  
Salt Water ◽  
Net Photosynthesis ◽  
Green Ash ◽  
Long Term Effects ◽  
Seedling Mortality ◽  
Oil Drilling ◽  
Four Levels

Seedlings of green ash (Fraxinuspennsylvanica Marsh.) were subjected to four levels of salt water ranging from approximately seawater concentration to one-tenth the concentration of seawater to simulate a temporary intrusion of salt water in coastal areas and brine spills associated with oil-drilling activities. The effect of saltwater influx on subsequent stomatal behaviour and net photosynthesis was studied. Stomatal conductance was reduced up to 72% and net photosynthesis declined by as much as 86% in response to the application of saline water. Both responses were rapid and occurred shortly after treatment. In addition to substantial declines in stomatal conductance and net photosynthesis, plant water potential also declined after treatment. All levels of salt application resulted in leaf injury and the two highest concentrations caused rapid seedling mortality. The results of this study indicate that green ash seedlings are extremely sensitive to soil salinity and will not survive either saltwater intrusion or brine spills associated with oil-drilling activities. Potential long-term effects are discussed.

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 Physiological responses of beet plants irrigated with saline water and silicon application

2020 ◽  
Vol 11 ◽  
pp. E3113
Author(s):  
José Sebastião de Melo Filho ◽  
Toshik Iarley da Silva ◽  
Anderson Carlos de Melo Gonçalves ◽  
Leonardo Vieira de Sousa ◽  
Mario Leno Martins Véras ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Carbon Concentration ◽  
Saline Water ◽  
Block Design ◽  
Essential Element ◽  
Net Photosynthesis ◽  
Crop Productivity ◽  
Experimental Unit ◽  
Randomized Block Design

Although not considered an essential element, silicon can be used to increase crop productivity, especially under stress conditions. In this sense, the objective was to evaluate the gas exchange of beet plants irrigated with saline water depending on the application of silicon. The experiment was conducted in a randomized block design, in a 5 x 5 factorial, referring to five levels of electrical conductivity of irrigation water (ECw): (0.5; 1.3; 3.25; 5.2 and 6.0 dS m-1) and five doses of silicon (0.00; 2.64; 9.08; 15.52 and 18.16 mL L-1), with six beet plants as an experimental unit. The effect of treatments on beet culture was evaluated at 30 and 60 days after irrigation with saline water from measurements of internal carbon concentration, stomatal conductance, net photosynthesis rate, instantaneous water use efficiency and instantaneous carboxylation efficiency using the LCpro+Sistem infrared gas analyzer (IRGA). Irrigation with saline water reduced the gas exchange of beet plants at 60 days after irrigation, but at 30 days after irrigation, the use of saline water increased stomatal conductance, transpiration rate and internal carbon concentration. The application of silicon decreased stomatal conductance, internal carbon concentration and efficiency in the use of water, but increased the rate of net photosynthesis, the rate of transpiration and instantaneous efficiency of carboxylation at 30 and 60 days after irrigation.

scholarly journals Investigation of saline water intrusions into the Curonian Lagoon (Lithuania) and two-layer flow in the Klaipėda Strait using finite element hydrodynamic model

Ocean Science ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 573-584 ◽  
Author(s):  
P. Zemlys ◽  
C. Ferrarin ◽  
G. Umgiesser ◽  
S. Gulbinskas ◽  
D. Bellafiore
Keyword(s):  
Finite Element ◽  
Model Simulation ◽  
Saline Water ◽  
Salt Water ◽  
Curonian Lagoon ◽  
Salt Water Intrusion ◽  
Exchange Flow ◽  
Directional Flow ◽  
The North ◽  
Layer Flow

Abstract. This work is focused on the application of a modelling system to simulate 3-D interaction between the Curonian Lagoon and the Baltic Sea coastal waters and to reflect spatiotemporal dynamics of marine waters in the Curonian Lagoon. The model system is based on the finite element programme package SHYFEM which can be used to resolve the hydrodynamic equations in lagoons, coastal seas, estuaries and lakes. The results of a one year (2009) 3-D model simulation with real weather and hydrological forcing show that the saline water intrusions from the sea through Klaipėda Strait are gradually decreasing with distance from the sea and become negligible (average annual salinity about 0.57‰) at a distance of about 20 km to the south of Kiaulės Nugara island. Analyses of the simulation results also show this area to be highly heterogeneous according to the vertical salinity distribution. While in the deeper Klaipėda Strait (harbour waterway) differences in average salinity between near bottom and surface layers varies in the range 2–2.5‰, in the rest of the Curonian Lagoon it is less than 0.5‰. The exchange flow showed vertical structure, but was horizontally uniform with the presence of a two-directional flow that from time to time changes to either saline water one-directional flow to the Curonian Lagoon or fresh water one-directional flow to the sea. Two-directional flow duration decreases with a distance from sea entrance in Klaipėda Strait from around 180 days yr−1 close to the sea entrance to 50 days yr−1 just behind Kiaulės Nugara island. One-directional outflow duration is increasing with a distance from the sea entrance from 100 to 225 days yr−1. One-directional inflow duration occurs in the range of 70–100 days yr−1. The analysis of the ratio of buoyancy layer thickness to water depth (hb/H) and the Wedderburn number identified the main importance of wind action on the flow structure. Strong winds from the North and NW determine a barotropic inflow which is mostly responsible for the salt water intrusion into the Curonian Lagoon. Absence of wind or cross-strait wind regimes allows the maintenance of a two-layer flow typical of estuarine dynamics.

scholarly journals Physiological Indicators in Two Lettuce Cultivars Under Saline Stress

2021 ◽  
Vol 13 (4) ◽  
pp. 52
Author(s):  
Marcos Antonio Dantas de Oliveira ◽  
Paulo Torres Carneiro ◽  
Maria Claudjane Jerônimo Leite Alves ◽  
Thayse Valéria e Silva ◽  
Gilberto da Cruz Gouveia Neto ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Saline Water ◽  
Net Photosynthesis ◽  
Water Salinity ◽  
Saline Stress ◽  
Physiological Indicators ◽  
Osmotic Effect ◽  
Randomized Design ◽  
Salinity Levels ◽  
Green Index

Lettuce (Lactuca sativa L.) is considered as the main leafy vegetable in Brazil. In the last decades, there had been many changes in the predominant varietal types in the country, however, issues regarding the use of saline water inhibit the growth by the osmotic effect. The aim of this study is avaliate the effect of water salinity on physiological in lettuce cultivars. The experiment was carried out at the Alagoas Federal University, Arapiraca Campus, in a completely randomized design and with a 5 × 2 factorial scheme, with six replications. Five treatments of water salinity levels were analyzed (ECw: 0.14, 1.54, 2.94, 4.34, and 5.74 dS m-1 at 25 °C) in two types of lettuce crops (Saia Véia and Vitoria Verdinha). Stomatal conductance, net photosynthesis, transpiration rate, water use efficiency, leaf temperature, and green index were assessed at 10, 20, and 30 days after the application of the treatments. The saline stress caused by the increase in saline concentrations decreased the photosynthesis and transpiration rates, which were associated with the reduction of stomatal conductance in both cultivars. Nevertheless, Saia Véia cultivar was higher tolerance in all tested saline levels compared to Vitória Verdinha. The green index for Vitoria Verdinha was seven times higher when compared to Saia Véia from the lowest to the highest saline levels. The cultivars differ in salt sensitivity, which could be useful for producers to choose the cultivar that is most adapted to the region and breeders regarding improvement prospects for adaptation of the lettuce under saline stress. In addition to osmotic stress, which is the first to happen, there are others.

scholarly journals A study of salt water intrusion in the Kallada river, south west coast of Kerala, India

2021 ◽  
Author(s):  
S. Chithra ◽  
Sabu Joseph ◽  
N. Kannan
Keyword(s):  
Ground Water ◽  
Negative Impact ◽  
Saline Water ◽  
Salt Water ◽  
Water System ◽  
River System ◽  
Salt Water Intrusion ◽  
Microbiological Analysis ◽  
Water Intrusion ◽  
Physico Chemical

Abstract Munroe Island in Kollam District of Kerala is a typical backwater village situated at the confluence of the Ashtamudi backwater and the Kallada river system. It is an amalgamation of eight small islands with a total area of 13.4 sq. km. Salinity intrusion has been a serious threat in the downstream areas of Kallada river for more than one and half decades, affecting the groundwater quality of Munroe Island. The present study focuses on the seasonal variation in physico-chemical characteristics of the underground water system of Munroe island and Kallada river with special reference to saline water intrusion. Physico-chemical analysis of ground water revealed that samples were unsuitable for drinking due to higher content of Na, Ca, and K. Microbiological analysis of island groundwater showed the presence of coliform and E-coli bacteria above the permissible limit. Results indicated a significant correlation between salinity and major anions viz., Cl− and SO42 and cations viz., Mg, Na, Ca, and K of both river surface and island groundwater. In the present study it is clearly evident the occurrence of salt water intrusion in Kallada river from Ashtamudy lake and the its severity become higher during premonsoon season. The results also indicated that the salinity increase in kallada river has a negative impact on island ground water quality. The paper also suggest suitable management strategies for overcoming the salt water intrusion thereby upgrading island sustainability.

scholarly journals The Effects of Salinity Changes on the Respiratory Rate of the Prawn Palaemonetes Varians (Leach)

1956 ◽  
Vol 33 (4) ◽  
pp. 730-736 ◽  
Author(s):  
B. LOFTS
Keyword(s):  
Salt Marsh ◽  
Respiratory Rate ◽  
Sea Water ◽  
Saline Water ◽  
Salt Water ◽  
Tap Water ◽  
Drainage Ditches ◽  
Low Salinity ◽  
Salinity Changes ◽  
British Coast

1. Palaemonetes varians, variety microgenitor, commonly inhabits only saline water around the British coast. It is, however, abundant in water of extremely low salinity in the Cardiff area, where it occurs in the drainage ditches of farm land adjacent to an area of salt-marsh. 2. Animals from areas of both high and low salinity were subjected, in the laboratory, to a range of salinities varying from pure tap water to concentrated sea water. The rate of respiration at each salinity was measured. 3. The population that inhabited the almost fresh water in the ditches differed physiologically from the salt-water form, although morphologically they were identical. 4. The salt-water population showed a minimum respiratory rate when in a medium of 26% NaCl salinity. This was expected, since the animal is isotonic at this salinity and the osmoregulatory work is minimal. The second population respired least when in a medium of 6% NaCl. The significance of this is discussed.

Net photosynthesis and stomatal conductance of red spruce twigs before and after twig detachment

1993 ◽  
Vol 23 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Fan-Rui Meng ◽  
Paul A. Arp
Keyword(s):  
Stomatal Conductance ◽  
Relative Humidity ◽  
New Brunswick ◽  
Photosynthetically Active Radiation ◽  
Regression Models ◽  
Net Photosynthesis ◽  
Leaf Temperature ◽  
Red Spruce ◽  
Active Radiation ◽  
Before And After

Rates of net photosynthesis and stomatal conductance of red spruce (Picearubens Sarg.) twigs were measured in field conditions before and after twig detachment on clear midsummer days in New Brunswick. Although these variables did not change significantly within about 6 min after twig detachment, they did drop continually after detachment. Regression models for the rates of net photosynthesis and stomatal conductance were developed that can be used to simulate this drop. Photosynthetically active radiation, leaf temperature, relative humidity, and CO2 concentration were the principal covariates in these models. The regressions improved by including simulated leaf moisture values in the analysis of data obtained after twig detachment.

Saline water intrusion adjacent to the Fraser River, Richmond, British Columbia

2001 ◽  
Vol 38 (1) ◽  
pp. 67-82 ◽  
Author(s):  
Laurie Neilson-Welch ◽  
Leslie Smith
Keyword(s):  
Dynamic Equilibrium ◽  
Saline Water ◽  
Salt Water ◽  
Ground Surface ◽  
River Channel ◽  
Low Flow ◽  
Salt Water Intrusion ◽  
Fraser River ◽  
Water Intrusion ◽  
River Bed

During periods of average to low flow in the Fraser River, seawater from Georgia Strait migrates with a rising tide up the river channel, reaching distances up to 16 km from the river's outlet to the ocean. This relatively dense water infiltrates through the river bed and circulates as a stable wedge of saline water within permeable deltaic deposits adjacent to the river. At the Kidd2 site in Richmond, the wedge extends approximately 500 m inland from the river. The top of the transition zone between fresh and saline water is 10 m below ground surface. The bottom of the saline wedge is located at the contact with underlying low-permeability delta slope deposits, resulting in a wedge with a vertical extent of approximately 10 m. Maximum salinity values observed in the wedge (16–17 parts per thousand) reflect the time-averaged response to density-driven flow under a complex sequence of daily and seasonal variations in salinity within the Fraser River and mixing with fresh river water that may enter the aquifer during the summer freshet. Under the assumption of dynamic equilibrium, simulation of the saline wedge at the Kidd2 site suggests (1) the effective, long-term average salinity at the base of the river channel is approximately 19 parts per thousand; (2) the velocity of groundwater, directed inland in the central portion of the wedge, is in the range from 0.5 to 6 m/year; and (3) fresh water in the confined deltaic sands moves from inland areas toward the Fraser River under a hydraulic gradient of approximately 3 × 10–4.Key words: salt water intrusion, deltaic sediments, modeling.

scholarly journals Morphophysiological responses of table beet irrigated with saline water under application of humic substances

2021 ◽  
pp. 970-976
Author(s):  
Leandra de Melo Cavalcante Sousa ◽  
Thiago Jardelino Dias ◽  
Lunara de Sousa Alves ◽  
Mário Leno Martins Véras ◽  
Ygor Henrique Leal ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Humic Substances ◽  
Saline Water ◽  
Block Design ◽  
Net Photosynthesis ◽  
Application Rate ◽  
Randomized Block Design ◽  
Electrical Conductivities ◽  
Internal Concentration ◽  
Semi Arid Region

The use of saline water is an alternative for irrigating agricultural crops, especially in the Brazilian Northeastern semi-arid region, where water quality is limited in most cases. Thus, the objective was to evaluate the morphophysiological responses of table beet cv. “Wonder” irrigated with saline waters under the application of humic substances. The experiment was conducted under a randomized block design, with six replications in a 6 x 4 x 5 factorial scheme, referring to six electrical conductivities of irrigation water (ECw): 0.5; 1.5; 2.5; 3.5; 4.5 and 5.5 dS m-¹, four humic substances rates (HS) (0; 10; 20 and 30 ml per plant), and five stages of assessment (23, 38, 53, 68 and 83 days after emergency). The characteristics evaluated were: plant height, number of leaves, leaf area, chlorophyll content (a, b and total), stomatal conductance, transpiration, net photosynthesis and CO2 internal concentration, and in the soil, the soil pH and the electrical conductivity of saturated paste extract. The increase of salinity reduced growth, chlorophyll a content, and the stomatal conductance of beet plants. The application rate of 30 ml per plant of humic substances promotes an increase in stomatal conductance. The application of humic substances raises the pH in sandy acidic soils. It is recommended to irrigate table beet plants with water of 0.5 dS m-1 associated with the application of 30 mL per plant of humic substances

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