Desert plant communities are among the most sensitive to changes in soil water conditions. In areas with shallow aquifers, it is important to understand both the effects of groundwater alterations on vegetation and how changes in surface-soil water affect plant water uptake. Studies in arid environments have evaluated the effect...
Biological di-nitrogen (N₂) fixation is a key process in open-ocean ecosystems, where the new nitrogen (N) provided by marine diazotrophs can support a large fraction of primary productivity and carbon (C) drawdown. Recent laboratory studies have shown that elevated pCO₂ enhances the rate of N₂ fixation by select laboratory isolates...
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RicardoM. Letelier
Biological di-nitrogen (N2) fixation is a key process in open-ocean
A graphical method, based on a set of acid-base titrations, is
presented for the determination of the carbon dioxide speciation in
natural solutions. The application of this method, in conjunction
with measurements of the partial pressure of carbon dioxide with
which our solutions were in equilibrium permitted the calculation
of...
The stoichiometric model of organic decomposition in seawater
(Redfield, Ketchum, and Richards, 1963) was used to describe the
oceanic distribution of total carbon dioxide. It was assumed that the
concentration of total carbon dioxide was the sum of three terms:
(1) the initial concentration of carbon dioxide, (2) the increase...
The apparent dissociation constants of carbonic acid were
determined as functions of temperature and salinity in seawater
at atmospheric pressure.
There is fair agreement between my values of K'₁ and those
of Buch et al. (1932), Lyman (1956), and Hansson (1971). My values,
on the average, are 6.7% lower than...