IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Decomposition and nutrients dynamics in a Spartina alterniflora marsh of the Bahia Blanca estuary, Argentina
Autor/es:
GABRIELA GONZÁLEZ TRILLA; VANESA L. NEGRIN; GERARDO M.E. PERILLO; PATRICIA KANDUS; JORGE E. MARCOVECCHIO
Lugar:
Cuiabá - Mato Grosso – Brasil.
Reunión:
Conferencia; 8th Intecol- International Wetlands Conference; 2008
Resumen:
Spartina marshes are highly productive, generating great amounts of detritus, which could release and uptake nutrients as it decompose. So, decomposition is a key factor to understand carbon and nutrients cycles in the coastal system. The objective of this work is to estimate aboveground and belowground decomposition rates in a S. alterniflora marsh located in Bahía Blanca estuary, and evaluate C, N and P content during this process. Litter bags with dry material were located in the marsh, and collected every 60 days during a year. We evaluated changes in mass, C, N and P concentrations. Our results show that decomposition rates were low with 71.23±1.91 % belowground and 52.69±3.59 % aerial mass remaining after a year. Aboveground decomposition showed a lineal pattern whereas underground decomposition showed an exponential one. In both cases maximum decomposition rates where not at the beginning of the experiment, showing no leaching phase. In aboveground tissues C, N and P concentrations of plant litter averaged 36.39±0.87, 0.75±0.08 and 0.035±0.006 whereas underground values where 41.12±0.64, 0.73±0.04 and 0.04±0.01 respectively. C:N ratio averaged 51.98±5.69 and 56.25±1.28 in underground and aboveground respectively. C:P and N:P ratios tended to increase with time in aerial bags, whereas buried bags showed initial fluctuations, and after that, tended to increase too. The low decomposition rates can be attributed to the high C:N ratios: decomposition proceeds slowly when this ratio attains values higher than 25. As C, N and P concentrations varied during the study, litter in this system seems to act as a source or a sink of nutrients at different moments.