INVESTIGADORES
CANEPUCCIA Alejandro Daniel
congresos y reuniones científicas
Título:
Effects of rainfall changes on S. densiflora cordgrass and the habitat use by Akodon azarae in a southwestern Atlantic saltmarsh
Autor/es:
PASCUAL, J.; CANEPUCCIA, A.D.; ALBERTI, J.; IRIBARNE, O.O.
Lugar:
Mar del Plata
Reunión:
Congreso; Coastal & Estuarine Research Federation, Mar del Plata 2012; 2012
Institución organizadora:
CERF
Resumen:
Planetary-scale events
like El Niño Southern Oscillation (ENSO) can alter rainfall patterns worldwide,
with important effects on the abundance and distribution of organisms and even
biological interactions. Despite the extensive evidence about the effects of
ENSO on marine and terrestrial systems, ecological consequences of rainfall
fluctuations in transitional communities remain poorly understood. The aim of
this study was to evaluate the effects of rainfall changes on marsh use by the
Pampas mice, Akodon azarae and its relationship with the cordgrass Spartina
densiflora. Field surveys, in a salt marsh of the South Western Atlantic coast
(Mar Chiquita coastal Lagoon 37° 45' S, 57º 23' W, Argentina), showed that the
abundance of A. azarae increased during rainy summers (e.g. El Niño 2004-2005,
El Niño 2006-2007), with the lowest abundance during the dry one (e.g. La Niña
2007-2008). Salt content in marsh sediments and plant tissues were negatively
correlated with rainfall levels. Field experiments manipulating sediment
salinity confirmed previous observations. Under salt stress conditions plant
growth decreased and the proportion of senescent tissues increased. Moreover
rodent abundance and the consumption of plants by them decreased. Results show
that rainfall fluctuations associated with ENSO events changed the physical
conditions in the marsh, decreasing the primary production and indirectly
modifying the habitat use by A. azarae and its trophic relationship with S.
densiflora.