Aquatic Plant Control Research Program. A Mathematical Model of Submersed Aquatic Plants
Aquatic Plant Control Research Program. A Mathematical Model of Submersed Aquatic Plants

Author: C. D. Collins

Publisher:

Published: 1985

Total Pages: 41

ISBN-13:

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Submersed auatic plants or macrophytes often contribute significantly to primary production in lakes and reservoirs. Macrtophyte growth and decomposition can influence the physical, chemical, and biological characteristics of aquatic ecosystems, including temperature and concentrations of dissolved oxygen, nitrogen, phosphorus, inorganic carbon, detritus, phytoplankton, and fish. A mathematical model of submersed aquatic macrophyte growth and decomposition was developed for use with the US Army Corps of Engineers' one-dimensional reservoir water quality model, CE-QUAL-R1, which was developed under the Environmental and Water Quality Operational Studies (EWQOS). The ecological processes recommended for inclusion with the macrophyte compartment include: gross production, dark respiration, photorespiration, nonpredatory mortality, and grazing. The influence of these processes on other compartments in CE-QUAL-R1 is described. Select process equations have been validated using a stand-alone version of the recommended model based upon experimental results derived from the literature and other research at the US Army Engineer Waterways Experiment Station for two macrophyte species, Myriophyllum spicatum and Hydrilla verticillata. Management control strategies can be simulated for mechanical harvesting and chemical control of the plants. Keywords: Aquatic ecology; Aquatic plants--Mathematical models; Eurasian watermillfoil; and Water quality management.

Aquatic Plant Control Research Program. Ecological Theory and the Management of Submersed Aquatic Plant Communities
Aquatic Plant Control Research Program. Ecological Theory and the Management of Submersed Aquatic Plant Communities

Author:

Publisher:

Published: 1995

Total Pages: 8

ISBN-13:

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The control of aquatic plant problems historically has been driven by short-term and very localized goals-immediate solutions for critical problems. However, in focusing on providing rapid solutions to specific problems, aquatic plant managers have often ignored longer term and system- wide management objectives. This "crisis management" approach- providing short-term, localized solutions to long-term or recurring problems-is unlikely to result in the most effective, system-wide management of aquatic resources. A holistic approach to aquatic plant management is needed. This article describes the development of innovative aquatic plant management strategies based on well-established principles of ecological succession. Population and community-based concepts borrowed from the body of basic ecological theory can help managers avoid extensive monocultures of problematic species, such as that shown in the photo below. The narrow perspective of most aquatic plant management plans results both from agency funding constraints and from an inadequate understanding of the ecological functioning of large, multipurpose reservoir ecosystems. Fortunately, there is a considerable body of basic ecological theory that appears pertinent to the management of aquatic plants.

Aquatic Plant Control Research Program: Effects of Water Chemistry on Submersed Aquatic Plants: A Synthesis
Aquatic Plant Control Research Program: Effects of Water Chemistry on Submersed Aquatic Plants: A Synthesis

Author: R. M. Smart

Publisher:

Published: 1990

Total Pages: 22

ISBN-13:

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Submersed aquatic plants require a continual supply of inorganic carbon to fuel photosynthesis. However, the aquatic environment imposes limits on both the supply and availability of inorganic carbon. Several factors, including alkalinity, dissolved inorganic carbon (DIC), and pH, affect the availability of inorganic carbon. These factors are among the most important water chemistry parameters with respect to their potential effects on the growth and distribution of submersed aquatic plants. Many submersed plants exhibit adaptations enabling them to more readily acquire inorganic carbon from the aquatic environment. A common adaptation is the ability to use bicarbonate (usually the predominant form of DIC) in photosynthesis. Photosynthesis in bicarbonate users, typified by Eurasian watermilfoil, is roughly proportional to DIC concentration. While photosynthesis is directly related to DIC, the relationship between plant biomass production and DIC is less clear. Factors other than DIC (such as nutrient limitation) also affect biomass production. Although inorganic carbon supply may limit growth rate, peak biomass attainment may be more likely limited by nitrogen availability. While water chemistry influences species distribution, it is unlikely that this factor is involved in limitations on biomass production.

Aquatic Plant Control Research Program: Methods for Monitoring Herbicide-Induced Stress in Submersed Aquatic Plants: A Review
Aquatic Plant Control Research Program: Methods for Monitoring Herbicide-Induced Stress in Submersed Aquatic Plants: A Review

Author:

Publisher:

Published: 1995

Total Pages: 45

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A technical meeting entitled "Physiological Assessment of Herbicide Stress in Aquatic Plants" was held 10 Jun 1993 at the U.S. Army Engineer Waterways Experiment Station by the Chemical Control Technology Team (CCTT) under the Aquatic Plant Control Research Program. Scientists from universities and government research facilities with common research interests in chemical control of plants and in aquatic weed physiology and ecology were invited to discuss physiological and biochemical methods of verifying and monitoring herbicide effects in submersed aquatic plants. This report summarizes the presentations and discussions by participants on general guidelines for choosing optimal assessment parameters and their suggestions for rapid and simple assays suitable for monitoring physiological changes, whether produced directly by the mode of action of aquatic herbicides or indirectly as a result of loss of metabolic function. Those assays expected to be readily implemented by the CCTT for research assessments of efficacy on target, nontarget, or off-target populations are briefly described.