Nitrification salinity

Shaffer et al. (1977) Dutt et al. (1972) model extended to tile-drained croplands and incorporated into a large irrigation return flow model to handle nitrogen as well as dissolved mineral constituents. Model allows user to select the degree of sophistication in simulation or to bypass certain subroutines. Zero-order denitrification and transition-state nitrification added. Model verified for salinity but not nitrogen. 

Rysgaard, S., Thastum, P., Dalsgaard, T., Christensen, P.B., and Sloth, N.P. (1999) Effects of salinity on NH4+ adsorption capacity, nitrification, and denitrification in Danish estuarine sediments. Estuaries 22, 21-30. 

Rysgaard et al. (1999) tested the effect of salinity on nitrification in a Danish estuary to determine whether the increased desorption of NH4+ from sediments was responsible for the decreasing nitrification rates at high salinity. They concluded that salinity influenced nitrification rates independently of NH4+ concentrations and suggested that some physiological factor must be involved. 

Magalhaes, C. M., Joye, S. B., Moreira, R. M., Weibe, W. J., and Bordalo, A. A. (2005). Effect of salinity and inorganic nitrogen concentrations on nitrification and denitrification rates in intertidal sediments and rocky biofifins of the Douro River estuary, Portugal. Water Research 9, 1783—1794. 

Meyer, R. L., Kjaer, T., and Revsbech, N. P. (2001). Use of NOx- microsensors to estimate the activity of sediment nitrification and NOx-consumption along an estuarine salinity, nitrate, and fight gradient. Aquatic Microbial Ecology 26, 181-193. 

Pakulski,J. D., Benner, R., Amon, R., Eadie, B., and Whitledge, T. (1995). Community metabolism and nutrient cycling in the Mississippi River plume Evidence for intense nitrification at intermediate salinities. Mar. Ecol. Prog. Ser. 117, 207—218. 

Lapping critical water quality indices in real time is necessary for the development and verification of realistic mathematical models of the ocean. The advent of automated chemical analyses and computer mapping (1-4) has made real-time mapping of static chemical properties a reality. But these static properties, for example, nutrient salts, chlorophyll, and salinity, are not sufficient to describe the state of a system, nor can they be used to predict the recovery of a perturbed system. The dynamic properties, especially those that control the remineralization and oxidation of organic matter to CO2 and NO3, namely oxygen consumption, denitrification, and nitrification, must be measured (5-8). These processes are... 

Figure 11 Depth profiles of (a) N2O concentration and (b) and (c) <5 0 of N2O at station ALOHA in the subtropical North Pacific (22° 45 N, 158° W) during four separate cruises. The solid line in (a) indicates theoretical saturation with atmospheric N2O at in situ temperatures and salinities. The minima in and <5 0 around 200 m are thought to be due to significant in situ production of N2O from nitrification. The broad isotopic maxima at depth are likely due to N2O consumption, perhaps in the denitrifying waters along the eastern Pacific margin. The filled squares at the top of (b) and (c) represent measurements of <5 N and <5 0 of atmospheric N2O during the Hawaii Ocean Time-series 76 cruise, and arrows indicate the range of historical measurements as of the late 1980s. Reprinted from Dore JE, Popp BN, Karl DM, and Sansone FJ (1998) A large source of atmospheric nitrous oxide from subtropical North Pacific surface waters. Nature 396 63-66.

Earlier explanations of these huge nitrate accumulations ranged from decay of aquatic plants in inland arms of the Pacific to nitrification and leaching of seabird gnano at the margins of saline lakes. In reality, the deposits were laid down not becanse of any exceptional source of mineral compounds bnt becanse the extraordi-... 

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