The growth and biomass distribution of two emergent freshwater plants, Cyperus esculentus and Scirpus validus, on different sediments

Abstract

The growth of two emergent freshwater plants, Cyperus esculentus L. and Scirpus validus Vahl., was investigated under greenhouse control in a simulated freshwater marsh environment. Plants were grown on one coarse and two fine-textured sediments differing significantly in phosphorus and nitrogen contents. Growth of both species, measured as total biomass accrual during a two-month period, was greatest on silty clay, intermediate on clay, and least on sand. Both shoot density (number of shoots per area) and the specific mass of individual shoots with regard to sediment type demonstrated patterns identical to that of total biomass. Below- to aboveground biomass ratios were inversely related to plant growth. The fine-textured sediments provided proportionately greater aboveground growth than the sand. Analysis of plant shoots indicated possible growth limitation by nitrogen on clay. Growth on silty clay was limited by neither nitrogen nor phosphorus, which were both present in the highest concentrations in this sediment. The biomass of both species on silty clay was within the range of most published estimates of the biomass of emergent freshwater plants in temperate regions of the world.