Decomposition and nutrients dynamics in a Spartina alterniflora marsh of the Bahia Blanca

VANESA L. NEGRIN; GABRIELA GONZÁLEZ TRILLA; PATRICIA KANDUS; JORGE E. MARCOVECCHIO

BRAZILIAN JOURNAL OF OCEANOGRAPHY

INST OCEANOGRAFICO

Año: 2011

1679-8759

In this work we estimate aboveground and belowground decomposition rates in a Spartinaalterniflora marsh located in Bahía Blanca estuary, and evaluate C, N and P dynamics during thisprocess. Litter bags with dry material were located in the marsh and collected every 60 days during ayear; we weighted each bag and determined C, N and P concentration in the tissues. Decompositionrates were 47.3 ± 3.6 and 28.8 ± 1.9 % of material lost after a year, for aboveground and belowgroundtissues, respectively. Decomposition showed a general exponential pattern, with maximum dailydecomposition rates not at the beginning of the essay, showing no leaching phase. The content of C, Nand P in aboveground tissues were, in average, of 41.45 ± 0.41 %, 0.73 ± 0.01 % and 0.049 ± 0.008 %,respectively, whereas in belowground tissues they were of 36.39 ± 0.86 %, 0.75 ± 0.07 % and 0.035 ±0.005 %, respectively. Ratios between elements were high in all cases, which may explain the lowdecomposition rates. The low rates and the fluctuations in the content of elements along the processmight suggest that decomposition is important for the nutrients dynamics in the estuary in the longterm. NOTA:TRABAJO ACEPTADO EN 2011 PERO PUBLICADO EN 2012