Accession Number : ADA195394

Title :   Aquatic Plant Control Research Program. Interactions between Macrophyte Growth and Sediment Nutrient Availability.

Descriptive Note : Final rept.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB

Personal Author(s) : Barko, John W ; Smart, R M ; Chen, Rex L

PDF Url : ADA195394

Report Date : Apr 1988

Pagination or Media Count : 31

Abstract : 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.

Descriptors :   *AQUATIC PLANTS, *PLANT GROWTH, AVAILABILITY, LIMITATIONS, NITROGEN, NUTRIENTS, PHOSPHORUS, POTASSIUM, SEDIMENTS, SOURCES, WATER, MARINE BIOLOGY

Subject Categories : Biological Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE