A nitrogen sensitive model of leaf carbon dioxide and water vapour gas exchange: application to 13 key species from differently managed mountain grassland ecosystems

1998 ◽  
Vol 113 (1-3) ◽  
pp. 179-199 ◽  
Author(s):  
Georg Wohlfahrt ◽  
Michael Bahn ◽  
Ingrid Horak ◽  
Ulrike Tappeiner ◽  
Alexander Cernusca
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Water Vapour ◽  
Mountain Grassland ◽  
Grassland Ecosystems ◽  
Key Species

Grassland dynamics of soil moisture and temperature

2021 ◽  
Author(s):  
Stefano Ferraris ◽  
Mesmer N'Sassila ◽  
Alessio Gentile ◽  
Marta Galvagno ◽  
Herve Stevenin ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Water Vapour ◽  
Land Use Changes ◽  
State Variables ◽  
Physical Processes ◽  
Matric Potential ◽  
Carbon Dioxide Fluxes ◽  
Community Land Model ◽  
Mountain Grassland ◽  
The Us

<p>Alpine ecosystems are vulnerable to climate and land use changes. Measurement sites at different altitude and aspect can provide precious information on them. Also, vadose rootzone plays a major role in partitioning fluxes. In this work field data of soil water content, matric potential and soil temperature in some mountain grassland sites are compared with simulations results of the CLM model (The Community Land Model, NCAR, US). These are key state variables regulating the physical processes that determine the flows of two main greenhouse gases, water vapour and carbon dioxide, to the atmosphere in the presence of vegetation.</p><p>Some transients show significant differences between data and CLM simulation results and further analyses are performed using the HYDRUS model from the US Salinity Laboratory, in order to better explore the soil, grass, and atmosphere roles in the dynamics of those state variables. Some insight is finally provided about the effects on water vapour and carbon dioxide fluxes.</p>

A canopy porometer for photosynthesis studies in field crops

1984 ◽  
Vol 62 (2) ◽  
pp. 290-295 ◽  
Author(s):  
Paul F. Daley ◽  
Conrad F. Cloutier ◽  
Jeremy N. McNeil
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Temperature Measurement ◽  
Water Vapour ◽  
Operating Characteristics ◽  
Respiratory Gas Exchange ◽  
Field Crops ◽  
Whole Plant ◽  
Chamber Light

A portable, modular porometer for whole-plant or canopy photosynthetic and respiratory gas exchange estimation is described. The system features within-chamber light and temperature measurement and in its present configuration permits analysis of carbon dioxide and water vapour exchange by an extension of the syringe-based "CO2 depletion" technique. Operating characteristics of the system and potential modifications are discussed, along with limitations and applications.

scholarly journals Band Emissivities of Carbon Dioxide and Water Vapour

1966 ◽  
Vol 32 (243) ◽  
pp. 1718-1725
Author(s):  
Ryozo ECHIGO ◽  
Niichi NISHIWAKI ◽  
Masaru HIRATA
Keyword(s):  
Carbon Dioxide ◽  
Water Vapour

Eddy covariance flux measurements of momentum, heat and carbon dioxide in Hudson Bay at the onset of sea ice melt 

2021 ◽  
Author(s):  
Richard Sims ◽  
Brian Butterworth ◽  
Tim Papakyriakou ◽  
Mohamed Ahmed ◽  
Brent Else
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Sea Ice ◽  
Eddy Covariance ◽  
Open Water ◽  
The Arctic ◽  
Gas Transfer ◽  
Hudson Bay ◽  
Flux Measurements ◽  
Ice Fraction

<p>Remoteness and tough conditions have made the Arctic Ocean historically difficult to access; until recently this has resulted in an undersampling of trace gas and gas exchange measurements. The seasonal cycle of sea ice completely transforms the air sea interface and the dynamics of gas exchange. To make estimates of gas exchange in the presence of sea ice, sea ice fraction is frequently used to scale open water gas transfer parametrisations. It remains unclear whether this scaling is appropriate for all sea ice regions. Ship based eddy covariance measurements were made in Hudson Bay during the summer of 2018 from the icebreaker CCGS Amundsen. We will present fluxes of carbon dioxide (CO<sub>2</sub>), heat and momentum and will show how they change around the Hudson Bay polynya under varying sea ice conditions. We will explore how these fluxes change with wind speed and sea ice fraction. As freshwater stratification was encountered during the cruise, we will compare our measurements with other recent eddy covariance flux measurements made from icebreakers and also will compare our turbulent CO<sub>2 </sub>fluxes with bulk fluxes calculated using underway and surface bottle pCO<sub>2</sub> data. </p><p> </p>

Respiration in man during metabolic alkalosis

1962 ◽  
Vol 17 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Daniel J. Stone
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Lung Function ◽  
Gas Exchange ◽  
Metabolic Alkalosis ◽  
Time Lag ◽  
Respiratory Compensation ◽  
Arterial Ph ◽  
Oral Sodium ◽  
Ventilation Response

A steady state metabolic alkalosis was induced in two subjects over a period of several days utilizing oral sodium bicarbonate in dosages of 50 g/day. The purpose of inducing steady state metabolic alkalosis was to study the effects of such a state on the respiratory center responses to inspired gas mixtures, containing carbon dioxide, and to contrast these results with the control studies. The experiment was so designed that the arterial pH in both subjects tended to return toward normal in the presence of significant increases in blood bicarbonate. Repeated study of ventilation responses with room air and 4% and 6% carbon dioxide in inspired air revealed a definite and significant decrease in ventilation response to carbon dioxide during the periods of steady state alkalosis as compared to the control periods. Normal responses returned after some time lag. A consistent rise in paCOCO2 occurred with alkalosis, thus demonstrating respiratory compensation. In neither subject was total lung function or gas exchange affected by the alkalosis. The experiment was confirmed on several occasions with reproducible results. Note: (With the Research Assistance of Mary Di Lieto) Submitted on May 22, 1961

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