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Physiological responses of transplanted populations of Sargussum pteropleuron Grunow in Florida
Title
Physiological responses of transplanted populations of Sargussum pteropleuron Grunow in Florida.
Creator
Dawes, Clinton J., Bird, Kimon T., Hanisak, M. Dennis
Date Issued
1988
PURL
http://purl.flvc.org/FCLA/DT/3353810
Subject Headings
Sargassum, Brown algae, Transplanting (Plant culture), Florida, Plant ecophysiology
Format
Document (PDF)
The multiple stress gradient hypothesis: expansion of the revised stress gradient hypothesis using a mangrove and salt marsh study system
Title
The multiple stress gradient hypothesis: expansion of the revised stress gradient hypothesis using a mangrove and salt marsh study system.
Creator
Coldren, Glenn A., Proffitt, C. Edward, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Plant interactions (e.g., competition, facilitation) are critical drivers in community development and structure. The Stress Gradient Hypothesis (SGH) provides a predictive framework for how plant species interactions vary inversely across an environmental stress gradient, predicting that facilitation is stronger with increasing levels of stress. The SGH has been supported in numerous ecosystems and across a variety of stress gradients, but recent research has demonstrated contradictory...
Show morePlant interactions (e.g., competition, facilitation) are critical drivers in community development and structure. The Stress Gradient Hypothesis (SGH) provides a predictive framework for how plant species interactions vary inversely across an environmental stress gradient, predicting that facilitation is stronger with increasing levels of stress. The SGH has been supported in numerous ecosystems and across a variety of stress gradients, but recent research has demonstrated contradictory results. These discrepancies have led to SGH revisions that expand its conceptual framework by incorporating additional factors, such as other stressor types and variations in species life history strategies. In this dissertation, I examine a further modification of the SGH by proposing and testing a Multiple Stress Gradient Hypothesis (MSGH) that considers how plant interactions vary along a continuous gradient of two co-occurring stressors using mangrove and salt marsh communities as a case study. In Chapter 1, I outline the predictive framework of a MSGH, by creating a series of predictions of species interactions. The components of the MSGH predict that stressors of similar types (e.g., resource and nonresource) will have similar effects and be additive. On the other hand, varying species life history strategies and life stages will lead to extremes of plant interactions. In Chapter 2, I performed a series of experiments to test the various components of the MSGH. In Chapter 3, I performed a large-scale observational study to test whether multiple co-occurring stressors altered the cumulative effects on plant interactions, and if these stressors should be grouped (e.g., resource and non-resource, abiotic and biotic, etc.) to enhance predictability. From a series of studies conducted herein, I concluded that co-occurring stressors are important factors that control complex species interactions as shown in my MSGH modeling approach. Further, future theories need to incorporate species-specific and stressor specific grouping when modeling how species interactions shape communities.
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Date Issued
2013
PURL
http://purl.flvc.org/fau/fd/FA0004011
Subject Headings
Coastal ecology, Ecophysiology, Mangrove ecology, Plant ecology, Salt marsh ecology
Format
Document (PDF)
The effect of sea level rise on Juncus Roemerianus in a high nutrient environment
Title
The effect of sea level rise on Juncus Roemerianus in a high nutrient environment.
Creator
Abbott, Cara J., Berry, Leonard, Florida Atlantic University, Charles E. Schmidt College of Science, Center for Environmental Studies
Abstract/Description
As sea levels continue to rise, the projected damage that will ensue presents a great challenge for conservation and management of coastal ecosystems in Florida. Since Juncus roemerianus is a common marsh plant throughout Florida with unique growing characteristics that make it a popular restoration plant, this study implemented a 20 week greenhouse split plot experiment to examine the effects of sea level rise on J. roemerianus and ultimately determine its tolerance ranges to salinity and...
Show moreAs sea levels continue to rise, the projected damage that will ensue presents a great challenge for conservation and management of coastal ecosystems in Florida. Since Juncus roemerianus is a common marsh plant throughout Florida with unique growing characteristics that make it a popular restoration plant, this study implemented a 20 week greenhouse split plot experiment to examine the effects of sea level rise on J. roemerianus and ultimately determine its tolerance ranges to salinity and inundation in a high nutrient environment. Overall, salinity level and the interaction effect of salinity level and water level had the greatest effects on measured growth parameters including average mature height, maximum height, density, basal area, root length, and biomass. An inverse relationship between increasing salinity and the measured growth variables was observed with the greatest growth and survivability in 0 ppt water, survivability and reduced growth in 20 ppt water, survivability and little growth in 30 ppt water, and nearly complete senesce in 40 ppt water. This was the first laboratory study to determine the effect of 40 ppt water on J. roemerianus. Elevated water levels resulted in higher growth variables in the 20 ppt, 30 ppt, and 40 ppt treatments while inundated water levels produced higher growth variables in the 0 ppt treatment despite previous research finding inundation to have completely adverse effects on J. roemerianus. It is likely that the high nutrient environment provided for this study is the cause for this anomaly. The results of this study have major implications for the future of coastal ecosystems that are dominated by stands of J. roemerianus in South Florida and can be used in conjunction with studies on bordering marsh plants to predict shifts in the ecosystems of Florida that are responding to sea level rise scenarios.
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Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00004426
Subject Headings
Coastal ecology, Coastal zone management, Jucus roemerianus, Plant ecophysiology, Salt marsh ecology, Sea level
Format
Document (PDF)