Download or read book Aquatic Plant Control Research Program Effects of Submersed Aquatic Macrophytes on Physical and Chemical Properties of Surrounding Water written by John W. Barko and published by . This book was released on 1988 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies were conducted to characterize physical and chemical gradients in submersed macrophyte beds located in limnologically contrasting environments--Eau Galle Reservoir, Wisconsin, and the Potomac River near Washington, DC. Various environmental factors were examined over specific periods at discrete depths to elucidate the effects of aquatic macrophytes on habitat conditions. Submersed aquatic macrophytes had both passive and active roles in influencing the physical and chemical attributes of their environment. Mixing of surface-heated water to lower depths was reduced as macrophytes became more abundant during the growing season. Intense metabolic activity significantly altered profiles of oxygen and pH within macrophyte beds as compared with open waters. In both study areas depthwise gradients in water temperature, dissolved oxygen, and pH exhibited strikingly greater variations over daily cycles in macrophyte beds than in adjacent open water. From results of these studies it is apparent that submersed macrophytes create distinct physical and chemical conditions that may influence the local distribution of other organisms. The steepening of environmental gradients by submersed macrophytes over both depth and time adds significantly to the complexity of the aquatic habitat. Keywords: Hydrilla, Nutrients, Water quality, Chlorophyll. (AW).

Download or read book Effects of Submersed Aquatic Macrophytes on Physical and Chemical Properties of Surrounding Water written by John W. Barko and published by . This book was released on 1988 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquatic Plant Control Research Program written by and published by . This book was released on 1991 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1989-03 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquatic Plant Control Research Program Effects of Water Chemistry on Aquatic Plants Interrelationships Among Biomass Production Plant Nutrition and Water Chemistry written by R. M. Smart and published by . This book was released on 1988 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of the submersed aquatic plants Egeria densa, Hydrilla verticillata, and Potamogeton nodosus was examined under two aeration regimes (ambient air and carbon dioxide (CO2)-enriched air) in three solutions differing in levels of major cations (calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K) and inorganic carbon (CT). Study objectives were to evaluate the effects of plant growth on solution chemical composition; interrelationships among solution chemistry, plant growth, and nutrition; and the relative importance of solution and sediment as potential growth-limiting factors. Plant growth was shown to be limited by inorganic carbon supply in the low-cation, low-carbon solution, and by sediment nitrogen (N) availability in the higher cation, higher carbon solutions. The response of submersed aquatic plants to solution was thus affected by sediment N supply. While plant requirements of N and P (phosphorus) were provided by root uptake from sediment, K was provided by foliar uptake from solution. Both inorganic carbon and sediment N were identified as factors potentially limiting the growth of field populations of submersed aquatic plants. Keywords: Aquatic plants, Carbon dioxide limitation, Egeria, Hydrilla, Nutrient limitation, Nutrient uptake, Potamogeton, Submersed macrophytes, Water chemistry.

Download or read book Aquatic Plant Control Research Program Effects of Water Chemistry on Submersed Aquatic Plants A Synthesis written by R. M. Smart and published by . This book was released on 1990 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Aquatic Plant Control Research Program A Mathematical Model of Submersed Aquatic Plants written by C. D. Collins and published by . This book was released on 1985 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book List of Publications of the U S Army Engineer Waterways Experiment Station written by U.S. Army Engineer Waterways Experiment Station and published by . This book was released on 1993 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquatic Plant Control Research Program Effects of Salinity and Irradiance Conditions on the Growth Morphology and Chemical Composition of Submersed Aquatic Macrophytes written by Robert R. Twilley and published by . This book was released on 1990 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrilla verticillata, Myriophyllum spicatum, Potamogeton perfoliatus, and Vallisneria americana were compared among different salinity and light conditions. The culture solution in five pairs of tanks was gradually adjusted to salinities of 0, 2, 4,6, and 12 ppt. With the exception of H. verticillata, the sea plants may be considered eurysaline species that are able to salinities one third the strength of seawater. With increasing salinity, the influorescence production decreased in M. spicatum and P. perfoliatus, yet asexual reproduction in the latter species by underground buds remained constant. Stem elongation increased in response to shading in M. spicatum, while shaded P. perfoliatus has higher concentrates of chlorophyll a. In association with high epiphytic mass, chlorophyll a concentrations in all species were greatest at 12 ppt. The concentration of sodium increased in all four species examined, indicating that these macrophytes did not possess mechanisms to exclude this ion. The nitrogen content of the plants tested increased significantly with higher sodium concentrate, suggesting that nitrogen may be used in osmoregulation.

Download or read book Aquatic Plant Control written by and published by . This book was released on 1979 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquatic Plant Control Research Program Effects of Water Chemistry on Aquatic Plants Interactive Effects of Inorganic Carbon and Nitrogen on Biomass Production and Plant Nutrition written by R. M. Smart and published by . This book was released on 1990 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of submersed Egeria densa, Hydrilla verticillata, and Myriophyllum spicatum was examined under 2 levels of inorganic carbon supply, at 2 sediment nitrogen levels, in a solution containing moderate levels of major cations and inorganic carbon. The study's primary objective was to evaluate the interactive effects of inorganic carbon supply and sediment N availability on plant growth and nutrition. Results indicate that both inorganic carbon supply and sediment N availability can limit growth of submersed aquatic plant populations. Egeria was more affected by inorganic carbon supply, Myriophyllum was more affected by sediment N availability, and Hydrilla was equally affected by both factors. Maximal plant growth of all species occurred under conditions of high inorganic carbon supply and high sediment N availability, indicating that suboptimal levels of either factor can depress growth. The results suggest the existence of a feedback loop regulating biomass production in submersed aquatic plants. Increases in the supply of either limiting factor may result in increased demand for the other factor, eventually resulting in low levels of both factors.

Download or read book Aquatic Plant Control Program written by and published by . This book was released on 1973 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Responses of Submersed Vascular Plant Communities to Environmental Change Summary written by Graham J. Davis and published by . This book was released on 1980 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquatic Plant Control Research Program Interactive Influences of Light and Temperature on the Growth and Morphology of Submersed Freshwater Macrophytes written by J. W. Barko and published by . This book was released on 1984 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Variations in the growth and morphology of three North American fresh-water macrophyte species, Elodea canadensis Michx., Potamogeton nodosus Poiret (P. americanus), and Vallisneria americana Michx., were investigated over broad experimental ranges of light and temperature. Response variables considered in the study included biomass production, shoot density, shoot length, and various characteristics of leaf form.

Download or read book Aquatic Plant Control Research Program The Habitat Value of Aquatic Macrophytes for Macroinvertebrates written by and published by . This book was released on 1989 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document summarizes and discusses recent studies on the value of submersed aquatic macrophytes for macroinvertebrates. Discussion on the effects of macrophytes on benthic invertebrates is followed by sections on the colonization of macroinvertebrates on Potamogeton nodosus and Ceratophyllum demersum. The next parts describe a study on the effects of macrophytes on distribution of zooplankton, the effects of C. demersum structure on macroinvertebrate colonization. The report concludes with a general summary and literature review of the effects of plants on biotic and abiotic factors in aquatic systems. The majority of these studies took place in Eau Galle Reservoir, Wisconsin, except for the final study of C. demersum, which was conducted in a borrow pit lake in Louisiana. Appendix A presents summary data on macroinvertebrates associated with aquatic macrophytes. Keywords: Aquatic plants; Invertebrates underwater habitats; Freshwater ecosystems. (EDC).

Download or read book Aquatic Plant Control Research Program Effects of Water Chemistry on Aquatic Plants Growth and Photosynthesis of Myriophyllum Spicatum L written by R. Michael Smart and published by . This book was released on 1986 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of the submersed macrophyte, Myriophyllum spictam L., was examined in nine solutions differing in major cation (Ca, Mg, Na, and K) and inorganic carbon C sub t levels. Growth experiments were conducted under two conditions differing in the relative magnitudes of gas exchange and solution volume. Under conditions of limited solution volume, growth was adversely affected by the combination of low cation (particularly Ca) and low C sub t levels. However, where solution volume was greater, there was no effect of cations. Irrespective of volume, growth was increased by increasing C sub t from 3.5 to 10.5 mg/l, but was unaffected by further increase in C sub t to 21.00 mg/l. Photosynthetic uptake of C sub t during growth reduced levels of C sub t and acidity and increased pH. Alkalinity and Ca levels were also reduced in some solutions due to the precipitation of CaCO3. Diurnal analyses indicated C sub t was not appreciably replenished during the night; thus, the experimental systems continually lost C sub t throughout the study. Initial photosynthesis rates, measured in the same solutions, indicated a strong relationship between photosynthesic and solution C sub t. Measurements of the exchange of CO2 between the atmosphere and the solution during the photosynthesis experiments revealed the potential importance of the atmosphere as a significant source of carbon. Keywords: Aquatic plants; Eurasion watermilfoil; Water chemistry.

Download or read book Aquatic Plant Control Research Program Effects of Organic Amendments to Sediment on Freshwater Macrophyte Growth written by J. W. Barko and published by . This book was released on 1983 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growth of three submersed macorphyte species (Myriophyllum spicatum, Hydrilla verticillata, and Elodea canadensis) and three partially emergent macrophyte species (Sagittaria latifolia, Myriophyllum aquaticum, and Potamogeton nodosus) was examined on a nonamended sediment and on the same sediment amended by additions of five types of vegetative organic matter (two labile and three refractory). With individual amendments, the organic content of the sediment was increased from an initial value of ca. 10 percent to a final value of 15 percent (low-level amendment) and from an initial value of ca. 15 percent to a final value of 20, 25, and 30 percent (high-level amendments). At equal levels of organic matter addition (low-level amendment), macrophyte growth varied with the type of amendment and the species of aquatic macrophyte. Biomass accrual by emergent species as a group was generally greater on all sediments, and was less inhibited than that of submersed species on amended sediments. At the high levels of amendment, the growth of representative submersed and emergent species was severely inhibited on all amended sediments irrespective of amendment type. The inhibitory influence of Hydrilla verticillata of sediment amended by additions of labile organic matter decreased with increasing sediment age relative to time of amendment.