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Title: Dissolved organic matter and lake metabolism: Biogeochemistry and controls of nutrient flux dynamics to fresh waters. Technical progress report, January 1, 1990--December 31, 1991

Abstract

The land-water interface region consists of two major components: the wetland, and the down-gradient adjacent littoral floating-leaved and submersed, macrophyte communities. Because of the importance of very high production and nutrient turnover of attached microbiota, a major emphasis of this investigation was placed upon these biota and their metabolic capacities for assimilation and release of organic compounds and nutrient retention and cycling. Examination of the capacities of wetland littoral communities to regulate fluxes of nutrients and organic compounds often has been limited to input-output analyses. These input-output data are an integral part of these investigations, but most of the research effort concentrated on the biotic and metabolic mechanisms that control fluxes and retention capacities and their effects upon biota in the down-gradient waters. The important regulatory capacities of dissolved organic compounds on enzyme reactivity was examined experimentally and coupled to the wetland-littoral organic carbon flux budgets.

Authors:
Publication Date:
Research Org.:
Univ. of Alabama, Dept. of Biological Sciences, Tuscaloosa, AL (United States)
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States)
OSTI Identifier:
296880
Report Number(s):
DOE/ER/60930-T1
ON: DE99001295; TRN: AHC29903%%278
DOE Contract Number:
FG05-90ER60930
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: [1992]
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; PROGRESS REPORT; WETLANDS; CARBON CYCLE; ORGANIC MATTER; LAKES; BIOGEOCHEMISTRY; NUTRIENTS; PLANTS; AQUATIC ORGANISMS; AQUATIC ECOSYSTEMS

Citation Formats

Wetzel, R.G.. Dissolved organic matter and lake metabolism: Biogeochemistry and controls of nutrient flux dynamics to fresh waters. Technical progress report, January 1, 1990--December 31, 1991. United States: N. p., 1992. Web. doi:10.2172/296880.
Wetzel, R.G.. Dissolved organic matter and lake metabolism: Biogeochemistry and controls of nutrient flux dynamics to fresh waters. Technical progress report, January 1, 1990--December 31, 1991. United States. doi:10.2172/296880.
Wetzel, R.G.. 1992. "Dissolved organic matter and lake metabolism: Biogeochemistry and controls of nutrient flux dynamics to fresh waters. Technical progress report, January 1, 1990--December 31, 1991". United States. doi:10.2172/296880. https://www.osti.gov/servlets/purl/296880.
@article{osti_296880,
title = {Dissolved organic matter and lake metabolism: Biogeochemistry and controls of nutrient flux dynamics to fresh waters. Technical progress report, January 1, 1990--December 31, 1991},
author = {Wetzel, R.G.},
abstractNote = {The land-water interface region consists of two major components: the wetland, and the down-gradient adjacent littoral floating-leaved and submersed, macrophyte communities. Because of the importance of very high production and nutrient turnover of attached microbiota, a major emphasis of this investigation was placed upon these biota and their metabolic capacities for assimilation and release of organic compounds and nutrient retention and cycling. Examination of the capacities of wetland littoral communities to regulate fluxes of nutrients and organic compounds often has been limited to input-output analyses. These input-output data are an integral part of these investigations, but most of the research effort concentrated on the biotic and metabolic mechanisms that control fluxes and retention capacities and their effects upon biota in the down-gradient waters. The important regulatory capacities of dissolved organic compounds on enzyme reactivity was examined experimentally and coupled to the wetland-littoral organic carbon flux budgets.},
doi = {10.2172/296880},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1992,
month =
}

Technical Report:

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  • The quantitative capacities of larger rooted aquatic plants, microflora attached to the large aquatic plants and to sediments, and the open-water phytoplankton algae and bacteria to control the fluxes and loadings of nutrients within lakes are being investigated. Each of the major communities of the wetlands, littoral zone, sediments, and open water are being analyzed to evaluate their capacities to regulate nutrient fluxes and loadings to and from the open water. All of the component subprograms are coupled to each other and address the general question of quantifying the regulatory capacities of attached macrophytes and microflora for nutrient loadings andmore » recycling, and how these biotic controls affect phytoplankton competition, succession, and productivity. 92 references, 7 figures.« less
  • The interrelated couplings between nutrient loadings from littoral and sediment sources to the open water, and how these fluxes are regulated by the population dynamics of growth, metabolism, senescence, and decomposition of attached littoral and wetland plants (submersed and emergent macrophytes; epiphytic and epipelic microflora) and the phytoplankton (algae and bacteria) have been analyzed. All of the subprograms are coupled to each other and address the general question of quantifying the regulatory capacities of attached macrophytes and microflora for nutrient loadings and recycling, and how these controls affect phytoplanktonic productivity, competition, and succession. The research progressed in three major areas:more » (1) wetland nutrient fluxes, (2) littoral controls of internal nutrient loadings from sediment sources, and (3) pelagial nutrient turnover and cycling rates.« less
  • This research concentrates on the importance of dissolved organic matter as the key functional way that the high littoral and wetland contributions regulates freshwater ecosystem metabolism (both running and standing waters). Much of this contribution is a result of the high DOM loadings and the slow but large decomposition of this massive dissolved detrital organic matter. The evidence for these concepts was gathered over the years both in these studies and many others, so that the pervasiveness of detrital dynamics is universally found as a major component of aquatic ecosystem metabolism. A second major area involves coupling the land-water interfacemore » metabolism to pelagic regulation via nutrient regulation. The research of the current studies focused upon (1) the physiological couplings between epiphytic periphyton and the supporting submersed macrophytes, and (2) the physiological capabilities of algae and bacteria to utilize enzymatically dissolved organic phosphorus compounds has been and is being examined rigorously along gradients from the littoral through the pelagic regions. The dissolved organic polyphenolic compounds of littoral and wetland macrophyte origins have been shown to be complex and inhibit phosphatase and other enzyme activities, and thereby regulate availability and uptake kinetics of limiting nutrients and subsequent growth. 323 refs., 26 figs.« less
  • These continuing investigations focus on integrated studies of the qualitative and quantitative cycling and metabolism of particulate and dissolved organic carbon in lakes and their inflow sources (surface and subsurface). Emphasis is placed on the sources, fates, and interactions of dissolved and particulate organic matter in relation to: inorganic chemical cycling, allochthonous loading to the lake system, and the coupled nutrient physiology and metabolism of phytoplankton, bacterial populations, macrophytes, and attendant sessile algal-bacterial communities. Regulatory mechanisms of growth and rates of carbon and nutrient cycling are being evaluated among the inorganic-organic influxes of allochthonous sources as they are controlled bymore » wetland-littoral communities, the littoral photosynthetic producer-decomposer complex, and the microflora of the pelagial zone. The integrated studies addressing these multifaceted objectives are summarized in a detailed outline.« less
  • Most lakes are small and possess large littoral and wetland components in the interface region between the open water per se and the drainage basin. Not only does the photosynthetic productivity of the surrounding littoral-wetland complex vastly exceed that of the pelagic zone, but the littoral-wetland vegetation and its intensive synthesis and decompositional metabolism regulate loading of inorganic nutrients passing to the open water (functioning as pulsed sources and sinks), and regulate loading of dissolved organic matter and particulate organic matter to the recipient open water, which by numerous complex pathways and mechanisms enhance or suppress pelagic productivity. Research emphasismore » was placed on the sources, fates, and interactions of dissolved and particulate organic matter in relation to inorganic chemical cycling: allochthonous loading to the lake system; and the coupled nutrient physiology and metabolism of phytoplankton, bacterial populations, macrophytes and attendant sessile algal-bacterial communities. Regulatory mechanisms of growth and rates of carbon and nutrient cycling were evaluated among the inorganic-organic influxes of allochthonous sources as they are controlled by wetland-littoral communities, the littoral photosynthetic producer-decomposer complex, the microflora of the sediment-water interface, and the microflora of the pelagic zone. 28 refs., 13 figs., 2 tabs.« less