The relationship between aboveground and belowground biomass of freshwater tidal wetland macrophytes

Aboveground and belowground biomass relationships of 15 annual and perennial freshwater tidal wetland macrophytes were examined. The data showed that regression equations may be used with confidence to estimate belowground biomass from aboveground biomass for most species. The linear regression model was suitable except for one species which had a large belowground component and for which the exponential model was more appropriate. Belowground: aboveground biomass ratios were significantly different for the 8 annual species examined. At peak biomass, all annuals allocated less than one third of the total net annual production into belowground structures. They exhibited distinct seasonal patterns of biomass allocation with more biomass incorporated into belowground components during the early part of the growing season. Perennial species exhibited 4 patterns of biomass allocation with Peltandra virginica (L.) Kunth having a significantly greater mean belowground: aboveground biomass ratio than other perennials. Factors that may control biomass allocation patterns include depth of rooting and life history strategies.