IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Tiller Dynamic and Production on a Spartina alterniflora Marsh at Bahía Blanca Estuary, Argentina.
Autor/es:
GABRIELA GONZÁLEZ TRILLA; PATRICIA KANDUS; VANESA L. NEGRIN; RICARDO L. VICARI; JORGE E. MARCOVECCHIO
Lugar:
Bahía Blanca, Buenos Aires
Reunión:
Simposio; ECSA 44 Symposium; 2008
Resumen:
 Biomass and primary production are key parameters of ecosystem health in coastal marshes. In this work, ramet dynamics and net aerial primary productivity (NAPP) were studied in a Spartina alterniflora marsh at Bahia Blanca estuary, by means of nondestructive methods applied to permanent sample plots along the 2005-2007 period. High and Low Marsh (HM and LM) sites were compared. Using the demographic data and phytometric equations both the new growth and exports of dead material were found throughout the year in S. alterniflora stands. Natality was similar in HM and LM (50.8±20.1 individuals·m-2) whereas mortality was greater in LM (113±32.4 individuals·m-2) compared to HM (90±28.7 individuals·m-2). Flowering period was in December and February and only HM tillers flowered, showing 1.43% flowered tillers·m-2 in the first year and 3.4% in the second one. The average dry mass was higher in the HM (55%) compared to the LM values (21.1%) reaching maximum values in winter (67.2% and 29.4% respectively). The average green standing biomass and green NPP showed a seasonal pattern peaking in February. The annual NAPP was estimated to be 547 g·m-2·yr-1 for the HM and 936±327 g·m-2·yr-1 and 482±87 g·m-2·yr-1 for the first and second period of the LM populations, respectively. Annual dry mass total production exported from the marsh was calculated as 876.46±248.71 g·m-2·yr-1 for the LM populations and 1369.5±296 g·m-2·yr-1 and 703.15±45.61 g·m-2·yr-1 for the first and second period of the HM populations. These results were the first published for S. alterniflora coastal marshes within the country, and provided a good background to understand the role of this species as a source of detritus to the estuary.