Above- and below-ground macrophyte production in Scirpus tidal marshes of the St. Lawrence estuary, Quebec

Abstract
Above- and below-ground standing crops as well as primary production of several macrophytes were estimated in Scirpus marshes along the south shore of the St. Lawrence River estuary in Quebec. Aboveground standing crop was measured by clipping vegetation, while belowground standing crop was estimated by soil coring. Seasonal variation of live and dead standing crops was first determined for different plant species. The root:shoot mass ratio was then examined and related to the life history of each species. Total aboveground production varied from 74 to 627 g ash-free dry mass∙m−2∙year−1 among different plant communities, whereas belowground production was lower, with estimates varying between 38 and 244 g∙m−2∙year−1. Production was lower along the St. Lawrence estuary than in other types of marshes located farther south.