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The influence of hydrologic variations onphosphorus cycling and retention in a swamp stream ecosystem
Title
The influence of hydrologic variations onphosphorus cycling and retention in a swamp stream ecosystem.
Creator
Yarbro, Laura A., Harbor Branch Oceanographic Institute
Date Issued
1983
PURL
http://purl.flvc.org/fau/fd/FA00007431
Subject Headings
Swamp ecology, Phosphorus cycle (Biogeochemistry), Wetland hydrology
Format
Document (PDF)
THE IMPACT OF NUTRIENT LOADING ON THE SOIL AND ROOT RESPIRATION RATES OF FLORIDA MANGROVES
Title
THE IMPACT OF NUTRIENT LOADING ON THE SOIL AND ROOT RESPIRATION RATES OF FLORIDA MANGROVES.
Creator
Faron, Natalie Therese, Benscoter, Brian, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description
Coastal nutrient loading is a growing concern in urbanized communities and has led to alterations in above- and belowground processes throughout estuarine systems. Mangrove forests are highly productive coastal habitats that exhibit large carbon stocks contained mostly to the deep soils. Since nutrient enrichment has been found to increase mangrove aboveground growth, it’s presumed that nutrient enrichment will also increase belowground respiration rates. Disturbances in soil nutrient content...
Show moreCoastal nutrient loading is a growing concern in urbanized communities and has led to alterations in above- and belowground processes throughout estuarine systems. Mangrove forests are highly productive coastal habitats that exhibit large carbon stocks contained mostly to the deep soils. Since nutrient enrichment has been found to increase mangrove aboveground growth, it’s presumed that nutrient enrichment will also increase belowground respiration rates. Disturbances in soil nutrient content may alter the mangrove carbon cycle by increasing the amount of CO2 lost to the atmosphere from enhanced microbial and root respiration. In this study, soil respiration responded greatest to nitrogen enrichment, but pneumatophore root respiration responded greatest to phosphorus enrichment. Nutrient limitation can shift between different ecological processes and responses to nutrient enrichment tend to be system specific in tidally influenced ecosystems. Understanding the implications of coastal nutrient loading will improve ecosystem models of carbon exchange and belowground processes.
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Date Issued
2021
PURL
http://purl.flvc.org/fau/fd/FA00013767
Subject Headings
Mangrove forests, Soil respiration, Carbon cycle (Biogeochemistry)
Format
Document (PDF)
Phosphorus uptake rates of a Ceratophyllum/periphyton community in a southern Florida freshwater marsh
Title
Phosphorus uptake rates of a Ceratophyllum/periphyton community in a southern Florida freshwater marsh.
Creator
Pietro, Kathleen C., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Net uptake rates of soluble reactive phosphate (SRP) of Ceratophyllum demersum and the dense periphyton mat associated with the macrophyte were calculated by measuring the disappearance of stable phosphorus (30, 50, 100, or 200 μg P/L) from the water column over a one-hour period each month for one year. Two seasonal periods were established based on average photosynthetically active radiation (PAR) and length of daylight through the year. ANOVA showed that the uptake rates were significantly...
Show moreNet uptake rates of soluble reactive phosphate (SRP) of Ceratophyllum demersum and the dense periphyton mat associated with the macrophyte were calculated by measuring the disappearance of stable phosphorus (30, 50, 100, or 200 μg P/L) from the water column over a one-hour period each month for one year. Two seasonal periods were established based on average photosynthetically active radiation (PAR) and length of daylight through the year. ANOVA showed that the uptake rates were significantly affected (P < 0.05) by the amount of SRP added and were greater during the period of increased irradiance. Uptake rates continued to increase, even at spike concentrations equal to 10,000 μg P/L, indicating that maximum uptake was not achieved and that this plant complex is able to sequester even greater amounts of SRP. Estimates of the yearly uptake capabilities of the plant complex for a 525 ha wetland for the 30, 50, 100, 200 μg P/L spike treatments were 27, 55, 103, and 182 kg P/yr, respectively.
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Date Issued
1998
PURL
http://purl.flvc.org/fcla/dt/15601
Subject Headings
Biology, Ecology, Biogeochemistry, Biology, Plant Physiology
Format
Document (PDF)
Investigating a Cryptic Iron-Nitrogen Cycle in Lake Okeechobee Sediments`
Title
Investigating a Cryptic Iron-Nitrogen Cycle in Lake Okeechobee Sediments`.
Creator
Silvera, Owen, Beckler, Jordon, Florida Atlantic University, Department of Marine Science and Oceanography, Charles E. Schmidt College of Science
Abstract/Description
The overall objective was to elucidate the effect of iron (Fe) on nitrogen (N) diagenesis in Lake Okeechobee. Somewhat counterintuitively, sediment ammonium (NH+4) inventories decreased during algal growth as dissolved organic nitrogen (DON) inventories increased. Whole core incubations were staged for denitrification experiments using isotopic N tracer. Core incubations showed the percentage of sediment N removal increase between summer (25 ± 21 %) and winter (39 ± 13 %). The amendment of...
Show moreThe overall objective was to elucidate the effect of iron (Fe) on nitrogen (N) diagenesis in Lake Okeechobee. Somewhat counterintuitively, sediment ammonium (NH+4) inventories decreased during algal growth as dissolved organic nitrogen (DON) inventories increased. Whole core incubations were staged for denitrification experiments using isotopic N tracer. Core incubations showed the percentage of sediment N removal increase between summer (25 ± 21 %) and winter (39 ± 13 %). The amendment of Fe2+ enhanced this seasonal effect likely via dissimilatory nitrate reduction to ammonium (DNRA). The isotopic signature of N2 flux also suggested an additional, sedimentary, N2 source via Fe coupled anaerobic oxidation of ammonium (feammox). Sediment slurry incubations supported the occurrence of both DNRA and feammox, showing first that nitrate (NO3−) was converted to NH4+ via DNRA, which contributed 23-26% of overall NO3− reduction. Fe amendment in slurries similarly stimulated the feammox process. However, aged Fe minerals accumulated linearly with N bound to Fe (Fe-N) in a subseasonal sediment time series, suggesting Fe-organic matter aggregation may lower the sediment NH4+ equilibrium concentration and benthic flux.
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Date Issued
2024
PURL
http://purl.flvc.org/fau/fd/FA00014486
Subject Headings
Okeechobee, Lake (Fla.), Diagenesis, Sediments (Geology), Biogeochemistry
Format
Document (PDF)
Respiration and carbon turnover rates of medusae from the NE Pacific
Title
Respiration and carbon turnover rates of medusae from the NE Pacific.
Creator
Larson, R. J., Harbor Branch Oceanographic Institute
Date Issued
1987
PURL
http://purl.flvc.org/FCLA/DT/3353790
Subject Headings
Medusae, Respiration, Carbon, Carbon cycle (Biogeochemistry)--Pacific Ocean Region
Format
Document (PDF)
The impact of willow encroachment on water and carbon exchange in the vegetation of a subtropical wetland
Title
The impact of willow encroachment on water and carbon exchange in the vegetation of a subtropical wetland.
Creator
Budny, Michelle L., Benscoter, Brian, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Shortened periods of inundation due to water management have led to the encroachment and expansion of Carolina willow (Salix caroliniana) in sawgrass (Cladium jamaicense) marsh communities. Morphologic and physiologic differences between sawgrass and willow have potential consequences for microhabitat conditions and ecosystem function such as a reduction in temperatures and light availability and changes in primary productivity. Since it is a woody shrub, willow is often assumed to exhibit...
Show moreShortened periods of inundation due to water management have led to the encroachment and expansion of Carolina willow (Salix caroliniana) in sawgrass (Cladium jamaicense) marsh communities. Morphologic and physiologic differences between sawgrass and willow have potential consequences for microhabitat conditions and ecosystem function such as a reduction in temperatures and light availability and changes in primary productivity. Since it is a woody shrub, willow is often assumed to exhibit higher rates of transpiration than non woody plants, which in turn can affect photosynthesis and carbon exchange and ultimately wetland water management. In this study willow was found to have higher rates of stomatal conductance (gs) and photosynthesis (Anet) than sawgrass. However, sawgrass had greater intrinsic water use efficiency (WUE) than willow. This suggests that willow is capable of greater gas exchange and carbon assimilation than sawgrass but requires more water. Understanding the implications of willow expansion will improve landscape models of wetland water and carbon exchange and inform water management decisions.
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Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00004350, http://purl.flvc.org/fau/fd/FA00004350
Subject Headings
Biogeochemistry, Ecosystem management, Surfaces (Technology) -- Measurement, Vegetation dynamics, Wetland ecology
Format
Document (PDF)
Investigating biogenic gas dynamics from peat soils of the Everglades using hydrogeophysical methods
Title
Investigating biogenic gas dynamics from peat soils of the Everglades using hydrogeophysical methods.
Creator
Wright, William J., Comas, Xavier, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Geosciences
Abstract/Description
Peat soils are known to be a significant emitter of atmospheric greenhouse gasses. However, the spatial and temporal variability in production and release of greenhouse gases (such as methane) in peat soils remains uncertain, particularly for low-latitude peatlands like the Florida Everglades, as the majority of studies on gas dynamics in peatlands focus on northern peatlands. The purpose of the work outlined here is focused on understanding the spatial and temporal variability in biogenic...
Show morePeat soils are known to be a significant emitter of atmospheric greenhouse gasses. However, the spatial and temporal variability in production and release of greenhouse gases (such as methane) in peat soils remains uncertain, particularly for low-latitude peatlands like the Florida Everglades, as the majority of studies on gas dynamics in peatlands focus on northern peatlands. The purpose of the work outlined here is focused on understanding the spatial and temporal variability in biogenic gas dynamics (i.e. production and release of methane and carbon dioxide) by implementing various experiments in the Florida Everglades at different scales of measurement, using noninvasive hydrogeophysical methods. Non-invasive methods include ground-penetrating radar (GPR), gas traps, time-lapse cameras, and hydrostatic pressure head measurements, that were constrained with direct measurements on soil cores like porosity, and gas composition using gas chromatography. By utilizing the measurements of in-situ gas volumes, we are able to estimate gas production using a mass balance approach, explore spatial and temporal variabilities of gas dynamics, and better constrain gas ebullition models. A better understanding of the spatial and temporal variability in gas production and release in peat soils from the Everglades has implications regarding the role of subtropical wetlands in the global carbon cycle, and can help providing better production and flux estimates to help global climate researchers improve their predictions and models for climate change.
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Date Issued
2018
PURL
http://purl.flvc.org/fau/fd/FA00013146
Subject Headings
Peat soils, Gas dynamics, Carbon cycle (Biogeochemistry), Everglades (Fla), Biogenic gas
Format
Document (PDF)
THE EFFECTS OF WILLOW SHRUB ENCROACHMENT ON SOIL ORGANIC CARBON STORAGE IN A SOUTH FLORIDA HERBACEOUS WETLAND
Title
THE EFFECTS OF WILLOW SHRUB ENCROACHMENT ON SOIL ORGANIC CARBON STORAGE IN A SOUTH FLORIDA HERBACEOUS WETLAND.
Creator
Dell, Jessica Ann, Benscoter, Brian, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description
Storing almost a third of the global soil carbon pool, wetlands are an essential component of the carbon cycle, and carbon-rich peat soil accumulates when carbon input through primary productivity exceeds output through decomposition. However, woody shrub encroachment in herbaceous wetlands can alter soil carbon processes, potentially diminishing stored carbon. To examine the effects of shrub encroachment on soil carbon, I compared soil carbon input through litterfall and fine root production...
Show moreStoring almost a third of the global soil carbon pool, wetlands are an essential component of the carbon cycle, and carbon-rich peat soil accumulates when carbon input through primary productivity exceeds output through decomposition. However, woody shrub encroachment in herbaceous wetlands can alter soil carbon processes, potentially diminishing stored carbon. To examine the effects of shrub encroachment on soil carbon, I compared soil carbon input through litterfall and fine root production, output through decomposition, and below-canopy microclimate conditions between Carolina willow shrub (Salix caroliniana) and herbaceous sawgrass (Cladium jamaicense) in the Blue Cypress Marsh Conservation Area (BCMCA), FL. To assess the level of production and its response to water level, I compared aboveground green biomass by measuring normalized difference vegetation index (NDVI) and photosynthetic stress by measuring photochemical reflectance index (PRI) between sawgrass and willow. I collected willow litterfall using litter traps and measured sawgrass and willow fine root production with fine root ingrowth bags. Litter decomposition was measured with decomposition bags deployed using a reciprocal litter placement design at BCMCA and incubated in a greenhouse to examine the effects of char and water level on decomposition. Above and belowground microclimate conditions were measured using sensors installed within sawgrass and willow canopies. Despite experiencing more photosynthetic stress, willow produced more green biomass than sawgrass. However, willow produced fewer fine roots than sawgrass and these roots were deeper within the soil. Willow litter decomposed faster even though sawgrass decomposition increased under drier conditions. Compared to the sawgrass canopy, the willow canopy had greater light availability, lower evaporative demand plus warmer and drier soils; however, litter decomposition did not differ between the canopies. These results suggest that willow encroachment can reduce the amount and alter the distribution of carbon within an herbaceous wetland, likely resulting in a net loss of soil carbon. Although willow encroachment may increase aboveground biomass carbon stocks, these stocks will likely be offset by a loss of soil carbon due to reduced fine root production and increased decomposition. Therefore, the transition from herbaceous wetland to shrub wetland will likely result in a loss of stored soil carbon.
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Date Issued
2020
PURL
http://purl.flvc.org/fau/fd/FA00013621
Subject Headings
Wetlands, Blue Cypress Water Management Area (Fla), Carbon cycle (Biogeochemistry), Soils
Format
Document (PDF)
Differentiating decomposition rates within the ridge-slough microtopography of the central Florida Everglades
Title
Differentiating decomposition rates within the ridge-slough microtopography of the central Florida Everglades.
Creator
Van der Heiden, Sheryl R., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
The relative rates of detrital decomposition in four vegetation communities within the Everglades' ridge-slough microtopography were evaluated during two trials. Litterbags with community-specific detritus in proportion to each community's composition were put into the four communities; namely, submerged marsh, emergent marsh, short Cladium ridge, and tall Cladium ridge. These litterbags were paired with litterbags containing control leaf litter from Chrysobalanus icaco and Salix caroliniana...
Show moreThe relative rates of detrital decomposition in four vegetation communities within the Everglades' ridge-slough microtopography were evaluated during two trials. Litterbags with community-specific detritus in proportion to each community's composition were put into the four communities; namely, submerged marsh, emergent marsh, short Cladium ridge, and tall Cladium ridge. These litterbags were paired with litterbags containing control leaf litter from Chrysobalanus icaco and Salix caroliniana during the wet and dry season trials, respectively. No regional differences in decomposition were shown, but there were significant differences across communities, attributed to the initial C:N ratio of the detritus, with the fastest decomposition occurring in the deepest submerged marsh followed by emergent marsh, and the shallower ridge communities had equally slower decomposition. Additionally, both controls followed the same pattern. Thus, decomposition contributes to an active self-maintenance mechanism within the vegetation communities which ultimately helps to conserve the ridges and sloughs.
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Date Issued
2008
PURL
http://purl.flvc.org/FAU/166456
Subject Headings
Biogeochemistry, Surfaces (Technology), Measurement, Vegatation dynamics, Mathematical models, Wetland ecology
Format
Document (PDF)
Elevated pCO2 effects on the macroalgal genus Halimeda: Potential roles of photophysiology and morphology
Title
Elevated pCO2 effects on the macroalgal genus Halimeda: Potential roles of photophysiology and morphology.
Creator
Peach, Katherine, Koch, Marguerite, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
While ocean acidification (OA) is predicted to inhibit calcification in marine macroalgae, species whose photosynthesis is limited by current dissolved inorganic carbon (DIC) levels may benefit. Furthermore, variations in macroalgal morphology will likely give rise to a range of OA tolerance in calcifying macroalgae. One genus of calcifying macroalgae that has shown varying species’ tolerance to OA is Halimeda, a major carbonate sediment producer on tropical reefs. Species within this genus...
Show moreWhile ocean acidification (OA) is predicted to inhibit calcification in marine macroalgae, species whose photosynthesis is limited by current dissolved inorganic carbon (DIC) levels may benefit. Furthermore, variations in macroalgal morphology will likely give rise to a range of OA tolerance in calcifying macroalgae. One genus of calcifying macroalgae that has shown varying species’ tolerance to OA is Halimeda, a major carbonate sediment producer on tropical reefs. Species within this genus occupy a range of habitats within tropical environments (reefs and lagoons), illustrating their ability to adapt to diverse environmental conditions (e.g. carbonate chemistry, irradiance). To date it is not clear if morphological and photophysiological diversity in Halimeda will translate to different tolerances to OA conditions (elevated pCO2 and lower pH).
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004621
Subject Headings
Coral reef ecology., Chemical oceanography., Halimeda., Environmental mapping., Plants--Effect of light on., Plant physiology., Photobiology., Carbon cycle (Biogeochemistry)
Format
Document (PDF)