Net aboveground primary production and soil properties of floating and attached freshwater tidal marshes in the Río de la Plata estuary, Argentina

Abstract

In the lower delta of the Parana´ River, at the head of the Rı´o de la Plata estuary (Argentina), we compared net aboveground primary production (NAPP) and soil properties of the dominant macrophyte Scirpus giganteus (Kunth) in a floating and an attached marsh community. Both marshes are tidally influenced but in different ways. The floating marsh site is relatively isolated from tidal influences because its ability to float makes it resistant to overland flow and to sediment inputs from the estuary. The attached marsh lacks the capacity to float and receives sediment supplies from the estuary through overland flow. These hydrologic differences are reflected in lower mineral content in sediments of the floating marsh. Using a leaf tagging technique, estimated NAPP was 1,109+-206 g m-2 y r-1 for the floating marsh and 1,866+-258 g m-2 y r-1 for the attached marsh. We attribute the lower NAPP of the floating marsh to isolation from sediment input from overland flow.