Identificador persistente para citar o vincular este elemento: http://hdl.handle.net/10553/136827
Título: Puzzling out the ecological niche construction for nitrogen fixers in a coastal upwelling system
Autores/as: Fontela, Marcos
Fernandez-Roman, Daniel
Broullon, Esperanza
Farnelid, Hanna
Fernández Carrera, Ana 
Maranon, Emilio
Martinez-Garcia, Sandra
Rodriguez-Ramos, Tamara
Varela, Marta M.
Mourino-Carballido, Beatriz
Clasificación UNESCO: 251001 Oceanografía biológica
Palabras clave: North Pacific
Ecosystem ria
N-2 fixation
Phytoplankton
Cyanobacteria, et al.
Fecha de publicación: 2025
Publicación seriada: ISME Communications 
Resumen: Diazotrophs are a diverse group of microorganisms that can fertilize the ocean through biological nitrogen fixation (BNF). Due to the high energetic cost of this process, diazotrophy in nitrogen-replete regions remains enigmatic. We use multidisciplinary observations to propose a novel framework for the ecological niche construction of nitrogen fixers in the upwelling region off NW Iberia-one of the most productive coastal regions in Europe-characterized by weak and intermittent wind-driven upwelling and the presence of bays. The main diazotroph detected (UCYN-A2) was more abundant and active during summer and early autumn, coinciding with relatively high temperatures (>16 degrees C), low nitrogen:phosphorus ratios (N:P < 7.2), and a large contribution of ammonium (>75%) to the total dissolved inorganic nitrogen available. Furthermore, nutrient amendment experiments showed that BNF is detectable when phytoplankton biomass and productivity are nitrogen limited. Seasonally recurrent biogeochemical processes driven by hydrography create an ecological niche for nitrogen fixers in this system. During the spring-summer upwelling, nondiazotroph autotrophs consume nitrate and produce organic matter inside the bays. Thereafter, the combined effect of intense remineralization on the shelf and sustained positive circulation within the bays in late summer-early autumn, conveys enhanced ammonium content and excess phosphate into the warm surface layer. The low N:P ratio confers a competitive advantage to diazotrophs since they are not restricted by nitrogen supply. The new nitrogen supply mediated by BNF could extend the productivity period, and may be a key reason why upwelling bays are more productive than upwelled offshore waters.
URI: http://hdl.handle.net/10553/136827
ISSN: 2730-6151
DOI: 10.1093/ismeco/ycaf018
Fuente: Isme Communications [ISSN 2730-6151], v. 5 (1), (Marzo 2025)
Colección:Artículos
Adobe PDF (1,83 MB)
Vista completa

Google ScholarTM

Verifica

Altmetric


Comparte



Exporta metadatos



Los elementos en ULPGC accedaCRIS están protegidos por derechos de autor con todos los derechos reservados, a menos que se indique lo contrario.