Growth and Development of Cyperus papyrus in a Tropical Wetland

Abstract

Relative growth rate (RGR) is an importantparameter in plant growth models. However, no field measurements of RGR havebeen made in Cyperus papyrus (papyrus) wetlands. In this study, the growth dynamics of aerial shoots wereinvestigated in a tropical papyrus wetland. The aim was to estimate temporalchanges in the growth rates, and also establish the effect of water level andtemperature change on total culm number, culm recruitment and senescence. Dryweights of shoots during their life cycle were determined using anon-destructive method after establishment of relationship between culmdiameter and dry weight. Measurements were made over period of seven months.During the course of the measurements, culm density significantly increasedfrom 16.1 to 35.9 culms.m-2. There were significant changes in both culm recruitment and senescence.Maximum RGR of developing culms was 1.04 g g-1 d-1. Using a culm density of 27 per m-2, productivityrange was 16.74 to 37.37 g m-2 d-1. There was an inverse and significantrelationship between rate of change in leaf weight ratio (LWR) and RGR of theculms. In conclusion, RGR of the aerial shoot development was controlled byrate of change in LWR from 41 to 156 days of growth. There was a strong andnegative influence of water level fluctuation on total culm density.