Download or read book Aquatic Plant Control Research Program Interactions Between Macrophyte Growth and Sediment Nutrient Availability 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: Aquatic macrophytes rely primarily on sediment as a direct source of nitrogen (N) and phosphorus (P). The availability of these nutrients in sediments is affected markedly by sediment type, and is also influenced by macrophyte growth. On sediments planted with Hydrilla verticillata Royal compared with control (unplanted) sediment, reductions of>90 percent and>30 percent in concentrations of exchangeable N and extractable P were measured during two 6-week periods of growth. Diminished N availability in sediments due to uptake by Hydrilla resulted in nutrient limitation of subsequent Hydrilla growth. Concomitant increases (>30 percent) in the concentration of exchangeable potassium (K) suggest that this element, obtained via foliar uptake from overlying water, may be exchanged by macrophyte roots for ammonium in sediment. Exchange of K for ammonium in sediments occurred only under conditions of N limitation in this species. Variations in the abilities of different aquatic macrophyte species to deplete sediment nutrients and to contend with autogenic reductions in nutrient availability may have an important influence on successional development in aquatic macrophyte communities and also may potentially affect element exchanges with overlying water.
Download or read book Interactions Between Macrophyte Growth and Sediment Nutrient Availability written by 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 Growth and Rooting Depth Characteristics of Hydrilla Verticillata L f Royle and Myriophyllum Spicatum L on Fertilized and Unfertilized Sediments written by and published by . This book was released on 1994 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a series of controlled greenhouse experiments, growth and rooting depth characteristics of Hydrilla verticillata (L.f.) Royle and Myriophyllum spicatum L. were examined relative to sediment-N availability, over a range of sediment depths from 10 to 60 cm. Each species was grown separately on fine- textured, inorganic sediment, either amended with ammonium chloride (N-amended) or rendered N-poor due to previous support of submersed macrophyte growth (nonamended). For both species, diminished biomass production was accompanied by increased root-to-shoot ratios and increased rooting depth (to 60 cm) on nonamended sediment. High production levels in Myriophyllum and Hydrilla on N- amended sediment were unaffected by sediment depth, indicating (along with high tissue N concentrations) that the availability of N under those conditions was nonlimiting. With increased depth of nonamended sediment, both Hydrilla and Myriophyllum increased production and mitigated N-deficiency in plant tissues by increasing root accession of this nutrient from greater sediment depths. This ability, speculated here to be more or less developed in other macrophyte species, may affect the outcome of interspecific interactions, particularly when N concentrations in sediment are low. Aquatic plants, Nitrogen, Sediment composition, Hydrilla, Nutrient limitation, Sediment nutrient availability, Myriophyllum, Nutrient uptake, Submersed macrophytes.
Download or read book Proceedings 27th Annual Meeting Aquatic Plant Control Research Program written by Aquatic Plant Control Research Program (U.S. Army Engineer Waterways Experiment Station). Meeting and published by . This book was released on 1993 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Sediment Nitrogen Availability and Plant Density on Interactions Between the Growth of Hydrilla Verticillata and Potamogeton Americanus Aquatic Plant Control Research Program written by and published by . This book was released on 1991 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study examines the growth of Hydrilla verticillata (L.f) Royle and Potamogeton americanus C. and S. on both nitrogen-poor and nitrogen-rich sediments and assesses the nature and degree of interspecific interactions between the two species. Extensive greenhouse experiments conducted from May through July 1989 employed sediments differing initially only in sediment nitrogen (fertilized containers: 0.21 + or - 0.01 mg exchangeable N per gram dry sediment; unfertilized containers: 0.01 + or -0.00 mg exchangeable N per gram dry sediment). Species were grown monotypically, as well as in 50:50 mixtures, on each sediment type. Although shoot production did not differ between species in monoculture, shoot production in Hydrilla was diminished by 60 to 76 percent in the presence of Potamogeton. Likewise, canopy development for Hydrilla was reduced in mixtures compared to monocultures, but Potamogeton did not show a similar reduction in canopy. High sediment nitrogen increased canopy development by 50 percent in both species. Above-ground biomass for monotypically grown species was similarly low on unfertilized sediment (6 to 8 g per container). However, on fertilized sediment, aboveground biomass in Potamogeton (approaching 25 g per container) was significantly greater than in Hydrilla (approximately 15 g per container). Aquatic plants, Macrophyte, Biomass, Nitrogen, Density, Production, Interspecific interaction, Sediment.
Download or read book Proceedings 22nd Annual Meeting Aquatic Plant Control Research Program written by Aquatic Plant Control Research Program (U.S. Army Engineer Waterways Experiment Station). Meeting and published by . This book was released on 1988 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings 29th Annual Meeting Aquatic Plant Control Research Program written by Aquatic Plant Control Research Program (U.S. Army Engineer Waterways Experiment Station). Meeting and published by . This book was released on 1995 with total page 344 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 Proceedings 21st Annual Meeting Aquatic Plant Control Research Program written by Aquatic Plant Control Research Program (U.S. Army Engineer Waterways Experiment Station). Meeting and published by . This book was released on 1987 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings 28th Annual Meeting Aquatic Plant Control Research Program written by Aquatic Plant Control Research Program (U.S. Army Engineer Waterways Experiment Station). Meeting and published by . This book was released on 1994 with total page 324 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 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.
Download or read book Proceedings 25th Annual Meeting Aquatic Plant Control Research Program written by Aquatic Plant Control Research Program. Meeting and published by . This book was released on 1991 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structuring Role of Submerged Macrophytes in Lakes written by Erik Jeppesen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid growth of the discipline of aquatic ecology has been driven both by scientific interest in the complexities of aquatic ecosystems and by their enormous environmental importance and sensitivity. This book focuses on the remarkably diverse roles played by underwater plants, and is divided into three parts: 10 thematic chapters, followed by 18 case studies, and rounded off by three integrative chapters. The topics range from macrophytes as fish food to macrophytes as mollusc and microbe habitat, making this of interest to aquatic ecologists as well as limnologists, ecosystem ecologists, microbial ecologists, fish biologists, and environmental managers.
Download or read book Proceedings 24th Annual Meeting Aquatic Plant Control Research Program written by Aquatic Plant Control Research Program (U.S. Army Engineer Waterways Experiment Station). Meeting and published by . This book was released on 1990 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Water Velocity and Sediment Composition on Competitive Interactions Between Native and Invasive Macrophyte Species in a Spring Fed River written by Jacob N. Bilbo and published by . This book was released on 2015 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrilla (Hydrilla verticillata) is an invasive species that is problematic globally and also in the San Marcos River where it competes with native species. Hydrilla has been described as the perfect aquatic weed because it is able to propagate under a wide range of environmental conditions including low nutrient and variable light conditions (Langeland 1996). Treatment methods for control of non-native aquatic plants can be restricted due to the co-occurrence of native endangered species, requiring an integrated approach of several methods for restoration, including removal by hand, and manipulating environmental factors to encourage growth of native species. I conducted a competition study to determine if a native species can out-compete non-native species under a set of environmental conditions. The experiment was conducted with in Spring Lake at the headwaters of the San Marcos River, Hays Co, Texas between 03/28/2014 and 05/21/2014. I used a three-factor replacement design; (water velocity, substrate type, and competitive pressure) to assess competitive interaction between a native species (Illinois pondweed) and non-native species (hydrilla). Illinois pondweed Potamogeton illinoensis) and hydrilla (Hydrilla verticillata) were potted in monoculture (intraspecific competition) and mixtures (interspecific competition) using sand or silt sediment, and high or low velocity for a period of seven weeks.
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).
