Benthic Microbial Food Webs: Spatial and Temporal Variations and the Role of Heterotrophic Protists in Salt Marsh Sediments. First, M. R. Ph.D. Thesis, University of Georgia, Athens, Georgia, 2008.
Benthic Microbial Food Webs: Spatial and Temporal Variations and the Role of Heterotrophic Protists in Salt Marsh Sediments [pdf]Paper  abstract   bibtex   
In order to determine if the loss of bacterial biomass varies over time, I investigated the microbial food web structure at two time scales in the salt marsh sediments of Sapelo Island, Georgia. Samples were collected monthly for one year at three contrasting subtidal locations: a high energy sandy beach, a muddy Spartina marsh, and a tidal creek bed. Concentrations of benthic microalgae (BMA), bacteria, heterotrophic protists, and metazoan meiofauna were measured at each location. Additionally, short-term dynamics of sediment microbial populations and bacterivory rates were investigated over a diel period in an intertidal creek bed to determine if variable rates of protist grazing could significantly impact bacterial standing stock. Although bacterivory rates were variable throughout the day, there were no periods of the day when protists could effectively reduce bacterial biomass. Yearly sampling revealed high variation in the microbial food web structure, mostly among sample locations. However, I observed a shift from a BMA-dominated community in the spring/ early summer months to a bacterial-dominated food web in the late summer/fall at all locations. Bacteria and heterotrophic protist concentrations were significantly related to porewater volume (6.9
@phdthesis{first_benthic_2008,
	address = {Athens, Georgia},
	title = {Benthic {Microbial} {Food} {Webs}: {Spatial} and {Temporal} {Variations} and the {Role} of {Heterotrophic} {Protists} in {Salt} {Marsh} {Sediments}},
	url = {http://gce-lter.marsci.uga.edu/public/uploads/first_matthew_r_200805_phd_20090909T164044.pdf},
	abstract = {In order to determine if the loss of bacterial biomass varies over time, I investigated the microbial food web structure at two time scales in the salt marsh sediments of Sapelo Island, Georgia. Samples were collected monthly for one year at three contrasting subtidal locations: a high energy sandy beach, a muddy Spartina marsh, and a tidal creek bed. Concentrations of benthic microalgae (BMA), bacteria, heterotrophic protists, and metazoan meiofauna were measured at each location. Additionally, short-term dynamics of sediment microbial populations and bacterivory rates were investigated over a diel period in an intertidal creek bed to determine if variable rates of protist grazing could significantly impact bacterial standing stock. Although bacterivory rates were variable throughout the day, there were no periods of the day when protists could effectively reduce bacterial biomass. Yearly sampling revealed high variation in the microbial food web structure, mostly among sample locations. However, I observed a shift from a BMA-dominated community in the spring/ early summer months to a bacterial-dominated food web in the late summer/fall at all locations. Bacteria and heterotrophic protist concentrations were significantly related to porewater volume (6.9},
	school = {University of Georgia},
	author = {First, Matthew R.},
	year = {2008},
	keywords = {GCE, microbial ecology, sediments, salt marsh, protists}
}
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