|Title||Community dynamics and differential species performance of benthic diatoms along a nitrate gradient|
|Publication Type||Book Chapter|
|Year of Publication||1995|
|Authors||R. Stevenson J|
|Editor||Kociolek JP, Sullivan M.J|
|Book Title||A Century of Diatom Research in North America. A Tribute to the distinguished careers of Charles W. Reimer and Ruth Patrick|
|Publisher||Koeltz Scientific Books USA|
The effects of specific concentrations of NO3-N on diatom community and population dynamics were studied in flowing water culture chambers. Diatoms were precolonized on artificial tiles and grown for 4 d in waters with NO3-N concentrations ranging from near 0 to 2000 ug/l. Growth rataes of all diatoms reached maximum levels at NO3-N concentrations of 300 ug/l or less. Maximum growth rates (ln(cells/cell) /l) of diatom species ranged from less than 0.0 to 0.644. Characterizations of reproductive performance and dispersal abilities also showed great differences among taxa. Analyses designed to identify patterns in tradeoffs between optimal reproductive and dispersal strategies showed little evidence for tradeoffs between reproductive potential of species in high and low NO3 concentrations, i.e., the same species tended to have the highest growth rates in low and high NO3 conditions. Analyses for sets of coadapted traits (such as high reproduction potentials and high dispersal rates for opportunistics) also showed not evidence in patterns of species characteristics. These results show that the great diversity of species in diatom communities may be due to the great niche diversity, with different species performing in very different ways.