A Simulation Model for Growth of the Submersed Aquatic Macrophyte Sago Pondweed (Potamogeton pectinatus L.)

Abstract

A simulation model for biomass dynamics of the submersed macrophyte Potamogeton pectinatus L. is presented. The model (POTAM) is based on carbon flow through the vegetation in meter-squared (m^) water columns. It includes descriptions of several factors that affect biomass dynamics, such as site characteristic changes in climate, temperature, water transparency, water level, pH, and oxygen effects on CO2 assimilation rate at light saturation, wintering strategies, mechanical control (removal of shoot biomass), and grazing. The characteristics of community and site can be easily modified by the user.POTAM incorporates insight into the processes affecting the dynamics of a sago pondweed community in relatively shallow, hard water (0.1-to 6-m depth; dissolved inorganic carbon concentration > 0.8 mmol and pH > 6), under ample supply of nitrogen and phosphorus in a pest-, disease-, and competitor-free environment under the prevailing weather conditions. It has been calibrated on data pertaining to a sago pondweed community in the Western Canal near Zandvoort, The Netherlands. At this site, growth starts from the subterranean tubers alone. Plant biomass usually peaks once a year, in July, and intensive downward transport of soluble carbohydrates occurs after anthesis, used for the formation of tubers that grow into the sediment.POTAM simulated the dynamics of plant and tuber biomass and tuber numbers in the Western Canal near Zandvoort, The Netherlands, well over a period of 1 to 5 years. Starting from measured instead of nominal tuber size increased the similarity between simulated and measured plant data. The importance of several plant speciescharacteristic properties was explored, namely, of leaf surface:dry weight ratio, tuber bank density, anchorage depth, and presence/absence of wintering shoots.The model has been used to calculate plant and tuber biomass and tuber numbers for other sites as well. In Lake Veluwe, The Netherlands, a site with a temperate climate, simulated plant biomass and newly produced tuber densities were similar to measured ones in two consecutive years, but timing in the simulated plants was delayed the second year. In the Byrnes Canal, California, with a far warmer temperate climate, simulated plant biomass and tuber bank density were similar to measured values when a lower self-shading coefficient than the nominal one and the same tuber size/tuber number per plant as measured were used. However, plant biomass and tuber bank density were lower with the nominal self-shading coefficient. In the tropical Lake Ramgarh, India, a simulated peak plant biomass similar to measured was found using the same lower self-shading coefficient as run for the California site, and almost no tubers were formed. Verification of simulated with measured tuber numbers was not possible, since tubers had not been measured.Several case studies are presented in which POTAM generated insight useful for management aimed at conserving or controlling sago pondweed populations. The model was used to calculate t...

A Bibliometric Analysis of Lake Restoration with Submerged Macrophytes

“…Although the temperature fluctuation in a water body is relatively small, its seasonal variation can markedly influence submerged macrophytes, especially under global climate warming scenarios. Previous studies have indicated that the lethal water temperatures of submerged macrophytes are generally less than 3 • C or higher than 45 • C [75,76]. In the temperature range of 10-20 • C, the seed germination rates of V. natans increase with temperature, but higher temperatures (e.g., 28 • C) may decrease the rates and speed up the germination [77].…”

Factors affecting the global distribution of Hydrilla verticillata (L. fil.) Royle: A review

“…It attained peaks of growth when the water temperature reached 28-29°C in the upper Paraná River (Sousa et al, 2010). Lethal water temperatures of SAMs are ones generally less than 3°C or higher than 45°C in their natural habitats (Best and Boyd, 2003;Christy and Sharitz, 1980). However, in a laboratory setting, H. verticillata has shown survival of some assessable physiological activities at 44°C, a finding that indicates its resilience towards thermophilicity (Chen, 1989; Van et al, 1976;Zhu et al, 2017).…”