Open AccessJournal Article
The role of standing dead Spartina alterniflora and benthic microalgae in salt marsh food webs: considerations based on multiple stable isotope analysis
TLDR
In this article, the stable isotope compositions (C, N, and S) of hve, senescent, and standing dead Spartina alterniflora were compared in order to determine the effects of aerial decomposition on the isotopic signature of aboveground S. alternjflora entering the food chain, which indicated that N2fixing microorganisms associdated with microalgal communities were an important source of N to salt marsh consumers.Abstract:
The stable isotope compositions (C, N, and S) of hve, senescent, and standing dead Spartina alterniflora were compared in order to determine the effects of aerial decomposition on the isotopic signature of aboveground S. dlterniflora tissue entering the food chain. Aerial decomposition of aboveground S. alterniflora resulted in a 6 to 18% increase in P S , and a 2 to 3 % decrease in 615N values; 613c values were unchanged. We describe mechanisms whereby the activity of fungi and epiphytic microorganisms may contribute to the observed shlfts in and 6I5N, respectively. The 613c value of salt marsh benthic and eplphytic microalgae ranged from -13.0% in summer to -17.6%0 in early spring. Average 6'\" values of microalgae and standing dead S. altemiflora were -0 3 and l.?%, respectively, reflecting the activity of NZ-fixing microorganisms. The 615N values for omnivorous and herbivorous salt marsh macrofauna ranged between 7.5 and 2.2% and for predatory Fundulus spp. averaged 9.2%. Given a presumptive + 3 % trophic shift in N assimilation, these results suggest that N2-fixing microorganisms associdted with microalgal communities were an important source of N to salt marsh consumers. The 6% 6'\"N, and 6\"'s values of primary producers were compared to the values of the following consumers: Fundulus spp., Uca spp., Ilyanassa obsoleta, and Littoraria irrorata. 6I3C VS 6 1 5 ~ and 613C vs 63JS dual isotope plots demonstrated that microalgae and standing dead S. alternjflora are important food resources in the North Carolina (USA) marshes we sampled. In addition, a compilation of literature values suggests that this is true in salt marshes throughout the East and Gulf coasts of North America. Future isotope studies of marsh food webs should include detrital Spartina spp. material in analyses of trophic structure.read more
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Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals
Michael J. DeNiro,Samuel Epstein +1 more
TL;DR: In this article, the influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition and found that the variability of the relationship between the δ^(15)N values of animals and their diets is greater for different individuals raised on the same diet than for the same species raised on different diets.
Dissertation
Ecological interactions and geological implications of foraminifera and associated meiofauna in temperate salt marshes of eastern canada
TL;DR: In this paper, a Mesocosm and Microcosm Experiments on the Feeding of Temperate Salt Marsh Foraminifera are described, and a taxonomic resolution and Tidal Gradients in Food Webs for Two Temperate salt Marshes: How Much Detail is Enough?
Dissertation
Assessment of mangrove and salt marsh mesocosm functional value using periwinkle snails, littoraria angulifera and littoraria irrorata, as an indicator
TL;DR: Swartwood et al. as mentioned in this paper investigated whether the age structure, population density, and distribution of Littoraria angulifera in the Smithsonian Institution's Florida Everglades mesocosm in Washington, DC is analogous to that of wild populations.
Dissertation
Isotope geochemistry of organic sulfur compounds with links to biogeochemical sulfur cycling and radical chemistry
TL;DR: Oduro et al. as mentioned in this paper reported one of the first sulfur isotope constraints on the factors that control the expression on the S-isotope effects of VOSCs and their natural precursors.
DissertationDOI
Anoxic metabolism in permeable sediments
TL;DR: This thesis investigates the pathways of dissolved inorganic carbon production in anoxic permeable sediments and the challenge of replicating flow conditions under anoxic conditions using FTRs and experimental design.
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Dissertation
Trophic structure and the importance of terrestrial wetland producers for aquatic food webs in tropical Australian estuaries
TL;DR: In this paper, stable isotope analysis of carbon and nitrogen was used to analyse processes of energy flow and assess the extend to which carbon fixed by terrestrial plants is incorporated into adjacent aquatic food webs in two intermittently connected estuarine pools in North Queensland, Australia.
Effect of heavy metals on salt march biota
TL;DR: Suntornvongsagul et al. as mentioned in this paper evaluated the effects of heavy metal contamination on the growth performance of the common salt marsh plant S. patens and associated arbuscular mycorrhizal fungi (AMF) colonizing its roots.
Chironomid Grazing on Benthic Microalgae in a
TL;DR: Chironomid larvae have the ability to consume significant fractions of the microphytobenthos in absolute terms, and relative to other meiofauna, indicating that they are an important component of the salt marsh food web.
DissertationDOI
Anoxic metabolism in permeable sediments
TL;DR: This thesis investigates the pathways of dissolved inorganic carbon production in anoxic permeable sediments and the challenge of replicating flow conditions under anoxic conditions using FTRs and experimental design.