<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Magalh</style></author><author><style face="normal" font="default" size="100%">Wiebe, William J.</style></author><author><style face="normal" font="default" size="100%">Joye, Samantha B.</style></author><author><style face="normal" font="default" size="100%">Bordalo, A. A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Inorganic Nitrogen Dynamics in Intertidal Rocky Biofilms and Sediments of the Douro River Estuary (Portugal)</style></title><secondary-title><style face="normal" font="default" size="100%">Estuaries</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">GCE</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><volume><style face="normal" font="default" size="100%">28</style></volume><pages><style face="normal" font="default" size="100%">592-607</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In this study rates of oxygen, ammonium (NH4+), nitrate (NO3-), nitrite (NO2-), and nitrous oxide (N2O) fluxes, nitrogen (N) fixation, nitrification, and denitrification were compared between two intertidal sites for which there is an abundant global literature, muddy and sandy sediments, and two sites representing the rocky intertidal zone where biogeochemical processes have scarcely been investigated. In almost all sites oxygen production rates greatly exceeded oxygen consumption rates. During daylight, NH4+ and NO3- uptake rates together with ammonification could supply the different N requirements of the primary producer communities at all four sites; N assimilation by benthic or epilithic primary producers was the major process of dissolved inorganic nitrogen (DIN) removal; N fixation, nitrification, and denitrification were minor processes in the overall light DIN cycle. At night, distinct DIN cycling processes took place in the four environments, denitrification rates ranged from 9 +/- 2 to 360 +/- 30 mmol N2 m^-2 h^-1, accounting for 10</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2005-93407</style></accession-num></record></records></xml>