Spatial and temporal variation in denitrification and in the denitrifier community in a boreal lake

2011

We investigated the spatial and temporal variation in denitrification rates (isotope-­pairing technique, IPT) and in the denitrifier community (examination of gene nirK by denaturing-gradient gel electrophoresis [DGGE] of microbial DNA) in the sediments of a boreal, clear-water, eutrophic lake using samples collected from shallow littoral, deep littoral and shallow profundal ­sediments during early summer, mid-summer, autumn and winter. The measured denitrification rates (44 to 613 µmol N m−² d−¹) are among the lowest ever reported from lacustrine sediments. Denitri­fi­cation rates varied both spatially and temporally, being highest in the profundal zone during mid-­summer and in the littor…