Carbon budget alteration due to landcover-landuse change in wetlands: the case of afforestation in the Lower Delta of the Parana River marshes (Argentina)

摘要

The objective of this work was to analyse the effects on carbon budget caused by the replacement of freshwater marshes by salicaceae plantations at ecosystem and regional scales, in the Lower Delta of the Parana River in Argentina. Biomass and net aboveground primary productivity were estimated for one of the main species planted in the delta, Salix babybnica var. sacramenta. and for the dominant species of the marshes that are most widespread in the study area, Scirpus giganteus and Schoenopkaus califomicus. Soil organic carbon was also estimated. Afforestation and marshes were mapped based on the digital classification of Landsat imagery. Aboveground biomass stored by afforestation is higher than by marshes (113.4Mg/ha vs. around 10Mg/ha). Nevertheless, soil organic matter accumulation is 10-fold higher in the marshes. A huge amount of carbon is released into the atmosphere when marshes are converted to forest due to change from a wetland to a terrestrial condition.