Sap flux-upscaled canopy transpiration, stomatal conductance, and water use efficiency in an old growth forest in the Great Lakes region of the United States

Abstract:While Africans are generally satisfied that a person of African descent was reelected to the White House following a campaign in which vicious and racist attacks were made against him, the U.S. Africa policy under President Barack Obama will continue to be guided by the strategic interests of the United States, which are not necessarily compatible with the popular aspirations for democracy, peace, and prosperity in Africa. Obama’s policy in the Great Lakes region provides an excellent illustration of this point. Since Rwanda and Uganda are Washington’s allies in the “war against terror” in Darfur and Somalia, respectively, the Obama administration has done little to stop Kigali and Kampala from destabilizing the Democratic Republic of the Congo (DRC) and looting its natural resources, either directly or through proxies. Rwanda and Uganda have even been included in an international oversight mechanism that is supposed to guide governance and security sector reforms in the DRC, but whose real objective is to facilitate Western access to the enormous natural wealth of the Congo and the Great Lakes region.

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Boron Supply and Water Deficit Consequences in Young ParicÃ¡ (Schizolobium parahyba var. amazonicum) Plants

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha44110136 ◽

2016 ◽

Vol 44 (1) ◽

pp. 250-256 ◽

Cited By ~ 1

Author(s):

Bianca do Carmo SILVA ◽

PÃªola Reis de SOUZA ◽

Daihany Moraes CALLEGARI ◽

Vanessa Ferreira ALVES ◽

Allan Klynger da Silva LOBATO ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Stomatal Conductance ◽

Gas Exchange ◽

Water Use Efficiency ◽

Water Deficit ◽

Water Use ◽

Electrolyte Leakage ◽

Tolerance Mechanism ◽

Schizolobium Parahyba ◽

Use Efficiency

Boron (B) is a very important nutrient required by forest plants; when supplied in adequate amounts, plants can ameliorate the negative effects of abiotic stresses. The objective of this study was to (i) investigate gas exchange, (ii) measure oxidant and antioxidant compounds, and (iii) respond how B supply acts on tolerance mechanism to water deficit in young Schizolobium parahyba plants. The experiment employed a factorial that was entirely randomised, with two boron levels (25 and 250 Âµmol L-1, simulating conditions of sufficient B and high B, respectively) and two water conditions (control and water deficit). Water deficit induced negative modifications on net photosynthetic rate, stomatal conductance and water use efficiency, while B high promoted intensification of the effects on stomatal conductance and water use efficiency. Hydrogen peroxide and electrolyte leakage of both tissues suffered non-significant increases after B high and when applied water deficit. Ascorbate levels presented increases after water deficit and B high to leaf and root. Our results suggested that the tolerance mechanism to water deficit in young Schizolobium parahyba plants is coupled to increases in total glutathione and ascorbate aiming to control the overproduction of hydrogen peroxide and alleviates the negative consequences on electrolyte leakage and gas exchange. In relation to B supply, this study proved that sufficient level promoted better responses under control and water deficit conditions.

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Apparent Tolerance of Low Water Availability in Temperate Asian Bamboos1

Journal of Environmental Horticulture ◽

10.24266/jeh-d-17-00009.1 ◽

2018 ◽

Vol 36 (1) ◽

pp. 7-13

Author(s):

Melissa C. Smith ◽

Richard N. Mack

Keyword(s):

Stomatal Conductance ◽

Water Use Efficiency ◽

Water Use ◽

North American ◽

Water Availability ◽

Irrigation Treatment ◽

Bamboo Species ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency ◽

Pleioblastus Chino

Abstract Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia but play only an incidental role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.

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Influence of biochar and microorganisms co-application on the remediation and maize productivity in cadmium-contaminated soil.

10.21203/rs.3.rs-927778/v1 ◽

2021 ◽

Author(s):

Fasih Ullah Haider ◽

Muhammad Farooq ◽

Muhammad Naveed ◽

Sardar Alam Cheema ◽

Noor ul Ain ◽

...

Keyword(s):

Stomatal Conductance ◽

Water Use Efficiency ◽

Water Use ◽

Transpiration Rate ◽

Synergistic Effects ◽

Photosynthesis Rate ◽

Cow Manure ◽

Cd Uptake ◽

Spad Value ◽

Use Efficiency

Abstract The synergistic effects of biochar and microorganisms on the adsorption of Cd and on cereal plant physiology remained unclear. Therefore, this experiment was performed to evaluate the combined effects of biochar pyrolyzed from (maize-straw (BC1), cow-manure (BC2), and poultry-manure (BC3), and microorganisms including (T. harzianum L. and B. subtilis L.), to evaluate, how incorporation of biochar positively influences microorganisms growth and nutrients uptake in plant, and how it mitigates under various Cd-stress levels (0, 10, and 30ppm). Cd2 (30 ppm) had the highest reduction in the intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate, which were 22.36, 34.50, 40.45, 20.66, 29.07, and 22.41% respectively lower than control Cd0 (0 ppm). Sole application BC, resulted in enhanced intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate were recorded in BC2, which were 7.27, 20.54, 23.80, 5.96, 13.37, and 13.50% respectively greater as compared to control and decreased the Cd-concentration in root and shoot of maize by 34.07 and 32.53%, respectively as compared to control. Similarly, among sole microorganism’s inoculation, minimized the Cd-concentration in shoot, root, and soil by 23.77, 20.15, and 10.35% respectively than control. These results suggested that integrated application of cow manure biochar BC2 and inoculation of microorganisms MI3 as soil amendments had synergistic effects in improving the adsorption of nutrients and decreasing the Cd-uptake in maize, and enhancing the physiology of plant grown in Cd-polluted soils as opposed to using either biochar or inoculating microorganisms alone.

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Chloride as macronutrient increases water use efficiency by anatomically‐driven reduced stomatal conductance and increased mesophyll diffusion to CO 2

The Plant Journal ◽

10.1111/tpj.14423 ◽

2019 ◽

Cited By ~ 4

Author(s):

Juan D. Franco‐Navarro ◽

Miguel A. Rosales ◽

Paloma Cubero‐Font ◽

Purificación Calvo ◽

Rosario Álvarez ◽

...

Keyword(s):

Stomatal Conductance ◽

Water Use Efficiency ◽

Water Use ◽

Use Efficiency

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Response of greenhouse-grown bell pepper (Capsicum annuum L.) to variable irrigation

Canadian Journal of Plant Science ◽

10.4141/cjps2013-048 ◽

2014 ◽

Vol 94 (2) ◽

pp. 303-310 ◽

Cited By ~ 14

Author(s):

Olanike Aladenola ◽

Chandra Madramootoo

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Water Use Efficiency ◽

Capsicum Annuum ◽

Water Use ◽

Irrigation Water ◽

Bell Pepper ◽

Marketable Yield ◽

Capsicum Annuum L ◽

Use Efficiency

Aladenola, O. and Madramootoo, C. 2014. Response of greenhouse-grown bell pepper (Capsicum annuum L.) to variable irrigation. Can. J. Plant Sci. 94: 303–310. In order to optimize water use in bell pepper production information about the appropriate irrigation water applications and agronomic and physiological response to mild and severe water stress is necessary. Different water applications were tested on yield, quality and water stress threshold of greenhouse-grown bell pepper (Capsicum annuum L.) cultivar Red Knight in 2011 and 2012 on the Macdonald Campus of McGill University, Ste Anne De Bellevue, QC. The study was carried out on a soil substrate in the greenhouse. Irrigation was scheduled with four treatments:120% (T1), 100% (T2), 80% (T3), and 40% (T4) replenishment of crop evapotranspiration in a completely randomized design. The highest marketable yield, water use efficiency and irrigation water use efficiency were obtained with T1 in both years. T1 received 20% more water than T2 to produce 23% more marketable yield than T2. Fruit total soluble solids content was highest in T4, and smallest in T1. The mean crop water stress index (CWSI) of the irrigation treatments ranged between 0.08 and 1.18. Leaf stomatal conductance of bell pepper was 75 to 80% lower in T4 than in T1. Regression obtained between stomatal conductance and CWSI resulted in a polynomial curve with coefficients of determination of 0.88 and 0.97 in 2011 and 2012, respectively. The result from this study indicate that the yield derived justifies the use of an extra quantity of water. Information from this study will help water regulators to make appropriate decision about water to be allocated for greenhouse production of bell pepper.

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A Methodology for Flash Drought Identification: Application of Flash Drought Frequency across the United States

Journal of Hydrometeorology ◽

10.1175/jhm-d-18-0198.1 ◽

2019 ◽

Vol 20 (5) ◽

pp. 833-846 ◽

Cited By ~ 18

Author(s):

Jordan I. Christian ◽

Jeffrey B. Basara ◽

Jason A. Otkin ◽

Eric D. Hunt ◽

Ryann A. Wakefield ◽

...

Keyword(s):

United States ◽

Great Lakes ◽

Great Plains ◽

Hot Spot ◽

The United States ◽

General Definition ◽

Corn Belt ◽

Great Lakes Region ◽

Rapid Rate ◽

Western Great Lakes

Abstract With the increasing use of the term “flash drought” within the scientific community, Otkin et al. provide a general definition that identifies flash droughts based on their unusually rapid rate of intensification. This study presents an objective percentile-based methodology that builds upon that work by identifying flash droughts using standardized evaporative stress ratio (SESR) values and changes in SESR over some period of time. Four criteria are specified to identify flash droughts: two that emphasize the vegetative impacts of flash drought and two that focus on the rapid rate of intensification. The methodology was applied to the North American Regional Reanalysis (NARR) to develop a 38-yr flash drought climatology (1979–2016) across the United States. It was found that SESR derived from NARR data compared well with the satellite-based evaporative stress index for four previously identified flash drought events. Furthermore, four additional flash drought cases were compared with the U.S. Drought Monitor (USDM), and SESR rapidly declined 1–2 weeks before a response was evident with the USDM. From the climatological analysis, a hot spot of flash drought occurrence was revealed over the Great Plains, the Corn Belt, and the western Great Lakes region. Relatively few flash drought events occurred over mountainous and arid regions. Flash droughts were categorized based on their rate of intensification, and it was found that the most intense flash droughts occurred over the central Great Plains, Corn Belt, and western Great Lakes region.

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