Search

Your search keyword '"Hagerthey, Scot"' showing total 26 results
Start Over Author "Hagerthey, Scot"
26 results on '"Hagerthey, Scot"'

13. Lipid Composition Differences of Periphyton, Crustaceans, and Small Fishes in Response to Eutrophication and Management in the Florida Everglades, USA.

Author

Bellinger, Brent J., Cook, Mark I., Hagerthey, Scot E., Newman, Susan, and Kobza, Robert M.

Abstract

Eutrophication of the Florida Everglades, USA, has altered the characteristics of the ecosystem, but management strategies are being implemented to accelerate recovery. In this study, we described lipid compositional similarities and differences between periphyton, fish, and crustaceans, and explored if eutrophication and creation of new open‐water sloughs in phosphorus (P)‐impacted regions of a Northern Everglades impoundment resulted in changes in periphyton biomass and lipid composition, and the lipid composition of a ubiquitous omnivore, Gambusia holbrooki. Lipid biomarker analysis provided insight into microbial community composition, quality of basal resources, and potential resources utilized by consumers. Periphyton biomass and phospholipid fatty acid (PLFA) composition differed in response to eutrophication, but not between P‐impacted control and treatment plots. Shifts in relative abundances of lipids indicative of diatoms and green algae mirrored known taxonomic shifts due to eutrophication. For fauna, PLFA were a small and relatively distinct component of the overall total lipid make‐up, and profiles were similar between control and treatment plots. However, the PLFA profile of G. holbrooki differed between oligotrophic and eutrophic regions. Fish and crustacean lipids contained significantly greater relative abundances of polyunsaturated fatty acids than were found in periphyton, and profiles differed between fish and crustaceans, suggesting organisms were selectively accumulating or elongating and desaturating lipids de novo, to meet physiological needs. This study builds on findings of microbial responses to eutrophication and recent observations that consumer PLFA profiles can also shift with P‐enrichment. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

15. Multiple regime shifts in a subtropical peatland: community-specific thresholds to eutrophication

Author

Statistics, Hagerthey, Scot E., Newman, Susan, Rutchey, Ken, Smith, Eric P., Godin, Jason, Statistics, Hagerthey, Scot E., Newman, Susan, Rutchey, Ken, Smith, Eric P., and Godin, Jason

Abstract

Ecosystems have a natural resilience to perturbations, where resilience is the magnitude of a disturbance that an ecosystem can resist before changes in structure, function, and services result in a regime shift. The Everglades region of Florida, USA, has been detrimentally impacted by phosphorus (P) enrichment and a regime shift from Cladium (sawgrass) to Typha (cattail) marsh has been described. We examine another facet of the low-nutrient Everglades stability regime, open-water sloughs, to determine if eutrophication leads to similar regime shifts. We analyzed surface water P and soil P as controlling variables that, once a critical threshold is surpassed, alter ecosystem state variables. Nonlinear relationships between P and vegetation were observed along a northern Everglades eutrophication gradient. In addition to the Cladium-Typha regime shift, a second independent regime shift, slough-Typha, was identified. Synoptic surveys of 49 sloughs within the boundary between the slough and Typha regime revealed that surface water total phosphorus (TP) and the benthic algal floc layer (BAFL) were the controlling variables, with critical thresholds of 11 mu g/L and 412 mg/kg, respectively. The slough regime below these thresholds was characterized by calcareous periphyton (BAFL TP 298 mg P/kg; BAFL calcium 149 g Ca/kg). Above the TP thresholds, vegetation composition shifted to open-marsh species with significantly higher BAFL TP (700 mg P/kg) and total organic carbon (TOC) ( 350 g C/kg). A second BAFL TP threshold occurred at 712 mg P/kg, above which Nymphaea dominated and BAFL TP ( 1034 mg P/kg) and TOC (417 g C/kg) significantly increased. Nymphaea sloughs transitioned to the Typha regime. The boundary reflects the loss of ecosystem resilience due to eutrophication. Both low-nutrient stability regimes (slough and Cladium) lie precariously close to the P critical threshold but differ in how eutrophication is absorbed and resisted. The slough regime transitions rapidly

Published
2008

19. Recent and Historic Drivers of Landscape Change in the Everglades Ridge, Slough, and Tree Island Mosaic

Author

Larsen, Laurel, primary, Aumen, Nicholas, additional, Bernhardt, Christopher, additional, Engel, Vic, additional, Givnish, Thomas, additional, Hagerthey, Scot, additional, Harvey, Judson, additional, Leonard, Lynn, additional, McCormick, Paul, additional, Mcvoy, Christopher, additional, Noe, Gregory, additional, Nungesser, Martha, additional, Rutchey, Kenneth, additional, Sklar, Fred, additional, Troxler, Tiffany, additional, Volin, John, additional, and Willard, Debra, additional

Published
2011
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results