Author: Katherine A. FriedmanPublisher:
ISBN:
Category : Coastal zone management
Languages : en
Pages : 88
Book Description
The Effects of Nitrate Fertilization on the Physiology of a Common Salt Marsh Cordgrass Species, Spartina Alterniflora
Author: Katherine A. FriedmanPublisher:
ISBN:
Category : Coastal zone management
Languages : en
Pages : 88
Book Description
The Effect of Nitrate Fertilization on the Photosynthetic Performance of the Salt Marsh Cordgrass Spartina Alterniflora
Author: Hillary L. SullivanPublisher:
ISBN:
Category : Coastal zone management
Languages : en
Pages : 110
Book Description
The Impact of Nutrient Loading on Nitrogen Removal and Carbon Dynamics in a Juncus Roemerianus and Spartina Alterniflora Dominated Salt Marsh in the Northern Gulf of Mexico
Author: Taylor LedfordPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 49
Book Description
Increased anthropogenic nutrient loading of nitrogen (N) and phosphorus (P) to estuaries and bays can lead to eutrophication, anoxia or hypoxia, and/or loss of native or other important species. Coastal salt marshes help to counteract eutrophication by removing excess N through microbially-mediated denitrification. One important factor that regulates salt marsh N removal is vegetation type, which affects sediment N-removal capacity by modifying redox potential and altering the microbial community structure within sediments. Additionally, plant community structure can alter carbon (C) uptake via photosynthesis and C release via sediment oxidation and organic matter degradation. A 1-year field study was conducted in a salt marsh located on Dauphin Island, AL, where we increased N and P inputs by 20 g N m-2 yr-1/ 1.25 g P m-2 yr-1 (low fertilization) and 40 g N m-2 yr-1/2.5 g P m-2 yr-1 (high fertilization) in plots dominated by either Juncus roemerianus (black needlerush) or Spartina alterniflora (smooth cordgrass). Denitrification was 5X higher in unamended J. roemerianus plots versus S. alterniflora, but denitrification in S. alterniflora was more responsive to fertilization, increasing ten-fold while denitrification in J. roemerianus plots did not respond to fertilization. Gross primary productivity (GPP) was marginally higher (~5%) in control plots of J. roemerianus than in control S. alterniflora plots. High fertilization increased GPP by 27% in S. alterniflora plots, however, GPP did not respond to fertilization in J. roemerianus plots. Additionally, ERCO2 was similar across vegetation types in control plots, and did not respond to fertilization in either vegetation type. Net ecosystem exchange was similar in J. roemerianus and S. alterniflora control plots and did not change in response to N and P additions for either vegetation type. Our results illustrate that while both J. roemerianus and S. alterniflora marshes have the capacity to withstand nutrient loading in the Gulf of Mexico via N removal, S. alterniflora dominated marshes may have a greater capacity to mitigate N inputs. Additionally, in a world with higher nutrient inputs and despite higher GPP in S. alterniflora, both vegetation types will continue to sequester C at similar rates.
Effects of Edaphic Factors on the Physiological Ecology of the Sah Marsh Cord Grass, Spartina Alterniflora Loisel
Author: Paul Micah BradleyPublisher:
ISBN:
Category : Salt marshes
Languages : en
Pages : 392
Book Description
Saltmarsh Cordgrass, Smooth Cordgrass, Spartina Alterniflora Loisel
Author: Gene M. SilberhornPublisher:
ISBN:
Category : Spartina alterniflora
Languages : en
Pages : 2
Book Description
Agrindex
Author: Growth Characteristics and Salt Tolerance of Two Reciprocally Invasive Grass Species Found in Coastal Salt Marshes
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 230
Book Description
An invasive variety of the common reed Phragmites australis, the M haplotpye, has been implicated in the spread of this species into North American salt marshes normally dominated by the salt marsh grass Spartina alterniflora (smooth cordgrass). Phragmites australis is spreading into North American coastal marshes that are experiencing reduced salinities, while Spartina spp. are spreading into northern European brackish marshes that are experiencing increased salinities. We compared the salt tolerance and other growth characteristics of the invasive, M haplotype with two native haplotypes (F and AC) in greenhouse experiments. The M haplotype retained 50% of its growth potential up to 0.4 M NaCl, whereas the F and AC haplotypes did not grow above 0.1 M NaCl. The M haplotype produced more shoots per gram of rhizome tissue and had higher relative growth rates than the native haplotypes on both freshwater and saline water treatments. The M haplotype also differed from the native haplotypes in shoot water content and the biometrics of shoots and rhizomes. The results offer an explanation for how the M haplotype is able to spread in coastal salt marshes and support the conclusion of DNA analyses that the M haplotype is a distinct ecotype of P. australis. We then compared the growth, competitive ability, salt tolerance and osmotic adjustment of M haplotype P. australis and S. alterniflora along a salinity gradient in greenhouse experiments. Spartina alterniflora produced new biomass up to 0.60 M NaCl, whereas P. australis did not grow well above 0.2 M NaCl. When the two species were grown in mixed cultures, P. australis was less affected by competition than S. alterniflora at lower salinities but the competitive advantage reversed above 0.2 M NaCl. The greater salt tolerance of S. alterniflora compared to P. australis was due to its ability to use Na+ for osmotic adjustment in the shoots. On the other hand, at low salinities P. australis was more competitive because it produced more shoots per gram of rhizome tissue than S. alterniflora. These studies illustrate how ecophysiological differences shift the competitive advantage from one species to another along a salinity gradient.
Decomposition of the Saltmarsh Cordgrass Spartina Alterniflora
Author: Leon Murray EmberPublisher:
ISBN:
Category : Decomposition (Chemistry)
Languages : en
Pages : 236
Book Description
The Effect of Salinity, Soil Aeration, and Insect Predation on the Free Amino Acid, Glycinebetaine, and Soluble Protein Levels of the Salt Marsh Cordgrass Spartina Alterniflora
Author: John D. BachellerPublisher:
ISBN:
Category : Spartina
Languages : en
Pages : 222
Book Description
Concepts and Controversies in Tidal Marsh Ecology
Author: M.P. WeinsteinPublisher: Springer Science & Business Media
ISBN: 0792360192
Category : Nature
Languages : en
Pages : 862
Book Description
Tidal salt marshes are viewed as critical habitats for the production of fish and shellfish. As a result, considerable legislation has been promulgated to conserve and protect these habitats, and much of it is in effect today. The relatively young science of ecological engineering has also emerged, and there are now attempts to reverse centuries-old losses by encouraging sound wetland restoration practices. Today, tens of thousands of hectares of degraded or isolated coastal wetlands are being restored worldwide. Whether restored wetlands reach functional equivalency to `natural' systems is a subject of heated debate. Equally debatable is the paradigm that depicts tidal salt marshes as the `great engine' that drives much of the secondary production in coastal waters. This view was questioned in the early 1980s by investigators who noted that total carbon export, on the order of 100 to 200 g m-2 y-1 was of much lower magnitude than originally thought. These authors also recognized that some marshes were either net importers of carbon, or showed no net exchange. Thus, the notion of `outwelling' has become but a single element in an evolving view of marsh function and the link between primary and secondary production. The `revisionist' movement was launched in 1979 when stable isotopic ratios of macrophytes and animal tissues were found to be `mismatched'. Some eighteen years later, the view of marsh function is still undergoing additional modification, and we are slowly unraveling the complexities of biogeochemical cycles, nutrient exchange, and the links between primary producers and the marsh/estuary fauna. Yet, since Teal's seminal paper nearly forty years ago, we are not much closer to understanding how marshes work. If anything, we have learned that the story is far more complicated than originally thought. Despite more than four decades of intense research, we do not yet know how salt marshes function as essential habitat, nor do we know the relative contributions to secondary production, both in situ or in the open waters of the estuary. The theme of this Symposium was to review the status of salt marsh research and revisit the existing paradigm(s) for salt marsh function. Challenge questions were designed to meet the controversy head on: Do marshes support the production of marine transient species? If so, how? Are any of these species marsh obligates? How much of the production takes place in situ versus in open waters of the estuary/coastal zone? Sessions were devoted to reviews of landmark studies, or current findings that advance our knowledge of salt marsh function. A day was also devoted to ecological engineering and wetland restoration papers addressing state-of-the-art methodology and specific case histories. Several challenge papers arguing for and against our ability to restore functional salt marshes led off each session. This volume is intended to serve as a synthesis of our current understanding of the ecological role of salt marshes, and will, it is hoped, pave the way for a new generation of research.