Native ecosystem replacement and carbon cycling: litter decomposition in native forest and pine plantations in the Semideciduous Atlantic Forest, Argentina

ZANINOVICH, SILVIA CLARISA; GATTI, MARÍA GENOVEVA

Buenos Aires

Simposio; 32nd New Phytologist Symposium: Plant Interactions with other organisms: molecules, ecology and evolution; 2013

New Phytologist Trust - IFEVA CONICET

Decomposition of organic matter is a complex biogeochemical process, that involves biotic and abiotic influences. This process controls ecosystem carbon (C) turnover and nutrient availability. Forests management and their replacement, could generate an increase of dead organic matter, which causes an increase in carbon emissions to the atmosphere due to decomposition. In order to assess native forest replacement effects on C cycling we estimate the decomposition rate of five plant species (three native trees: Chrysophyllum gonocarpum, Balfourodendron riedelianum and Cordia trichotoma, the commercial species Pinus taeda and a native bamboo Chusquea ramosissima) under two contrasting situations: native forest and pine plantations. We incubated decomposition bags for 1,3,6,9 and 12 months. Here we present preliminary results obtained at the first collection (30d of incubation). Pine and bamboo litter showed a low decomposition rate (~15-20%), and the tree native species had a greater decomposition rate but highly variable between species (~25-70%). At the moment no differences in litter decomposition rate were detected between the two contrasting situations. The replacement of forest by plantations and the increase in bamboo abundance (consequence of forest degradation) could decrease the incorporation of carbon to the soil and increase the carbon stock in the litter layer.