change, CO2 concentrations, and refixation of respired CO2 in stands of Populus tremuloides Michx., Pinus banksiana Lamb. and Picea mariana (Mill.) B.S.P. at the northern and southern boundaries of the central Canadian boreal forest. Midsummer gas exchange rates in Populus tremuloides were over twice those of the two conifer species, and Pinus banksiana rates were greater than Picea mariana rat...

A homemade CO2-laser photoacoustic spectrometer has been used for monitoring CO2 in gas samples extracted under vacuum from the wood of old spruce disc tree-rings for a ∼60 year series. The experimental results show that (1) the CO2 concentration exhibits annual trends correlated with an increase in atmospheric CO2 in a number of cases; (2) at the time when the annual CO2 trend changes from pos...

the solubility of co2 in the primary, secondary, tertiary and sterically hindered amine aqueous solutions at various conditions was studied. in the present work, the modified kent-eisenberg (m-ke), the extended debye-hückel (e-dh) and the pitzer models were employed to study the solubility of co2 in amine aqueous solutions. two explicit equations are presented to evaluate the concentration of h...

Dark respiration causes an increase in leaf CO2 concentration (Ci), and the continuing increases in atmospheric [CO2] further increases Ci. Elevated leaf CO2 concentration causes stomatal pores to close. Here, we demonstrate that high intracellular CO2/HCO3 (-) enhances currents mediated by the Arabidopsis thaliana guard cell S-type anion channel SLAC1 upon coexpression of any one of the Arabid...

We studied the influence of elevated atmospheric CO2 concentration ([CO2]) on the vacuolar storage pool of nitrogen-containing compounds and on the glycogen pool in the hyphal sheath of Amanita muscaria (L. ex Fr.) Hooker-Picea abies L. Karst. mycorrhizae grown with two concentrations of ammonium in the substrate. Mycorrhizal seedlings were grown in petri dishes on agar containing 5.3 or 53 mg ...

The ammonia compensation point ( ) controls the direction and magnitude of NH3 exchange between plant leaves and the atmosphere. Very limited information is currently available on how responds to anticipated climate changes. Young barley plants were grown for 2 weeks at ambient (400 μmol mol(-1)) or elevated (800 μmol mol(-1)) CO2 concentration with or NH4NO3 as the nitrogen source. The concent...

During expiration, the carbon dioxide (CO2) levels inside the dead space of a filtering facepiece respirator (FFR) increase significantly above the ambient concentration. To reduce the CO2 concentration inside the dead space, we attach an active lightweight venting system (AVS) comprising a one-way valve, a blower and a battery in a housing to a FFR. The achieved reduction is quantified with a ...

Great amounts of carbon dioxide generated by Pseudomonas denitrificans during high aerobic vitamin B12 fermentation, while the influence of CO2 concentration on vitamin B12 production remains unclear. In this paper, we present parallel experiments to investigate various levels of inlet CO2 fractions on the physiological metabolism of P. denitrificans in laboratory scale fermentation. The result...