Difference between revisions of "Salt Marsh"
From MicrobeWiki, the student-edited microbiology resource
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Revision as of 20:29, 9 April 2010
- 1 Introduction
- 2 Physical environment
- 3 Biological interactions
- 4 Microbial processes
- 5 Key Microorganisms
- 6 Examples of organisms within the group
- 7 Current Research
- 8 References
Salt marshes represent a transitional zone between terrestrial and marine ecosystems resulting in one of the most biologically productive habitats on earth. This productivity plays a major role in the nutrient cycles and food webs for both terrestrial as well as marine ecosystems. Migratory birds find abundant food resources from insects, mollusks, arthropods and fish. Marine fauna utilize the nutrient rich habitat creating a critical reproductive site for invertebrates and vertebrates groups including sharks and other fish species. This productivity is a result of major conflicting environmental factors that create harsh conditions with stressful levels of salinity, water submergence and low oxygen levels. Environmental conditions are shaped by daily tidal surges, major changes in seasonal fluctuations of freshwater, saltwater inundation during the occasional storm surges, and increased salinity during seasonal dry periods and evapotranspiration. Salinity at or greater than sea water at 34 g l-1 (3.4%) is the norm throughout the salt marsh resulting in significant Na fluxes. Regular inundation with fresh and salt water creates dramatic fluctuations in soil oxygen levels and sediment deposits. These extremes in salt and water saturations are beyond the tolerance of all but a few highly specialized organisms. Accumulated plant biomass and terrestrial runoff creates an exceptional N cycle. Essential to the productivity of the salt marsh through these various nutrient and chemical fluctuations is a diverse and unique microbial community supporting the flora and fauna of this habitat and sustaining the associated marine environment.