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Full-Text Articles in Life Sciences
Impacts Of Seasonality And Nutrients On Microbial Mat Community Structure And Function, James L. Pinckney, Hans W. Paerl, M. Fitzpatrick
Impacts Of Seasonality And Nutrients On Microbial Mat Community Structure And Function, James L. Pinckney, Hans W. Paerl, M. Fitzpatrick
Faculty Publications
To understand the mechanisms responsible for seasonal fluctuations in growth and N2 fixation in intertidal microbial mat communities, we quantified seasonal changes in mat community composition, related these changes to diel and seasonal N2 fixation rates, and evaluated community responses (growth, N2fixation, composition) to long-term (22 d) nutrient addition bioassays. A temperate intertidal cyanobacterial mat community, located in coastal North Carolina, USA, was sampled at monthly intervals for 1 yr (1993-94) to determine changes in community composition. The abundances of major phototrophic groups were quantified based on the relative concentrations of taxaspecific photopigments (chlorophylls and carotenoids). …
Community Metabolism And Nutrient Cycling In The Mississippi River Plume: Evidence For Intense Nitrification At Intermediate Salinities, Joseph D. Pakulski, Ronald Benner, Rainer Amon, Brian Eadie, Terry Whitledge
Community Metabolism And Nutrient Cycling In The Mississippi River Plume: Evidence For Intense Nitrification At Intermediate Salinities, Joseph D. Pakulski, Ronald Benner, Rainer Amon, Brian Eadie, Terry Whitledge
Faculty Publications
Community respiration, net nutrient fluxes and heterotrophic bacterial production were investigated in the Mississippi River (USA) plume during May 1992 using dark bottle incubations of unfiltered water. Highest rates of community O2 consumption and dissolved inorganic carbon regeneration were observed at intermediate (10 to 27%0) plume salinities. Plume surface 02 consumption rates were 2- to 4-fold greater than rates reported previously during the summer and winter. Heterotrophic bacterial production ([3H]-leucine incorporation) was also highest at intermediate salinities and 2- to 4-fold greater than rates reported from other seasons. Net regeneration of NH4+ …