INVESTIGADORES
MONTEMAYOR BORSINGER Diana Ireri
congresos y reuniones científicas
Título:
Characterization of Argentinean salt marsh Spartina wracks and their effects on sediment and associated biota
Autor/es:
DIANA IRERI MONTEMAYOR; JUAN L. FARINA; ALEJANDRO CANEPUCCIA; MARIANA ADDINO; MACARENA VALIÑAS; OSCAR IRIBARNE
Lugar:
Mar del Plata
Reunión:
Congreso; CERF´s Inaugural International Conference of the Americas, The Changing Coastal & Estuarine Environment: A Comparative Approach; 2012
Institución organizadora:
CERF
Resumen:
The aim of this study was to evaluate, at a regional scale, the patterns of Spartina wrack distribution, their dynamics and composition in South West Atlantic salt marshes (San Clemente 36º 19?S, Bahía Blanca 38º 59?S, Bahía Anegada 40º 19?S, mouth of Río Negro river 41º 01?S and Bahía San Antonio 40 44?S) and their effects on the sediment microclimatic conditions and biota. Field samplings revealed that the marsh height with larger amount of wrack coverage in all the studied marshes was the land-marsh limit. We also found that wrack detritus species composition depends largely on each marsh standing biomass assemblage (i.e. if dominated by Spartina alterniflora or S. densiflora) but likely also on the marsh geomorphology. The biomass wrack changed along the sampling dates (spring, summer and autumn) but without seasonal trends. Through a field experiment comparing wrack and bare zones we found that wracks in the land-marsh limit ameliorated extreme temperatures and on some occasions increased sediment humidity, while no effects were found for sediment organic matter content. The wracks also increased the number of individuals, the number of species and the diversity index for sediment biota. In conclusion, wracks have important effects on the microclimatic conditions of the sediment as well as in the sediment biota assemblage. Taking into consideration the latter, and the fact that they are widely distributed in SW Atlantic marshes, all evidence suggests that wracks plays an important role in the structuring of salt marshes sediment biotic assemblage.