Biogeochemical cycles in salt marshes from the Bahía Blanca estuary (Argentina): an overview

NEGRIN, V.; BOTTÉ, S.E.; PRATOLONGO, P.; GONZALEZ TRILLA, G.

Huesca

Congreso; WETLANDS 2014; 2014

Consejo Superior de Investigaciones Científica, Instituto Pirenaico de Ecología

Salt marshes are recognized worldwide for their key role in the biogeochemical cycling of elements. The Bahia Blanca estuary (Argentina) is a mesotidal system subjected to a unique combination of large interanual climatic variations and a transgressive rising sea level during the Holocene. This estuary holds the largest system of deep water ports in Argentina and is surrounded by cities and industries. Salt marshes are well-developed. We offer an insight on the biogeochemical cycles of heavy metals and nutrients in salt marshes based on the research which is being carrying out since 2000. The main halophytic species in the area, Spartina alterniflora and Sarcocornia perennis, accumulate some heavy metals in their tissues, but the former shows a higher allocation of them in belowground biomass and the later in aboveground biomass. Both species are modifiers of the distribution of inorganic nutrients in porewater, although tidal flooding is also a significant factor. Even though primary productivity is low, decomposition rates, especially from S.perennis, suggest an adequate recycling of elements through their tissues. Observed patterns are being altered due to changes in land cover, through S.perennis erosion and S.alterniflora expansion. Ongoing research will shed light of the complex patterns in this dynamic ecosystem