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Predictive Modeling Of Floral Species Richness In Michigan Prairie Fen Communities, Nichole R. Mason Dec 2014

Predictive Modeling Of Floral Species Richness In Michigan Prairie Fen Communities, Nichole R. Mason

Masters Theses

Prairie fens contain high levels of floral biodiversity, including 19 state threatened or endangered plant species, and are classified as rare and vulnerable communities by the Michigan Natural Features Inventory. The objective of this thesis was to develop multiple-regression (MR) models that reliably predict total, native, and invasive floral species richness for use by conservation organizations. Floral biodiversity surveys were conducted in eight southern Michigan prairie fens during the 2012 growing season. Simple linear regressions between fen size and biodiversity were used to optimize sampling strategy and effort (i.e., number of transects and plots per transect) in surveys conducted in …


Spatial Heterogeneity Of Ecosystem Metabolism In A Shallow Wetland, Daniel Riley Rackliffe Dec 2014

Spatial Heterogeneity Of Ecosystem Metabolism In A Shallow Wetland, Daniel Riley Rackliffe

Theses and Dissertations

Spatial heterogeneity in ecosystem metabolism may play a critical role in determining ecosystem functions. Variation in ecosystem metabolism between macrophyte patches in shallow wetlands at the extremes of freshwater habitats has not been investigated. We estimated ecosystem metabolism in mesocosms containing different macrophytes using 24-hour oxygen curves to test our hypotheses: (1) net aquatic production (NAP) during spring and summer would be similar among algal patches (metaphyton and Chara), (2) NAP in algal patches would be greater than patches dominated by the vascular plant Potamogeton foliosus, (3) heterotrophy and anaerobiosis would be greatest in patches dominated by Lemna, and (4) …


Wetland Sediment Nutrient Flux In Response To Proposed Hydrologic Reconnection And Climate Warming, James T. Smit Aug 2014

Wetland Sediment Nutrient Flux In Response To Proposed Hydrologic Reconnection And Climate Warming, James T. Smit

Masters Theses

Wetland restoration and creation are common practices, but wetlands restored or created on former agricultural land may act as a source of nutrients, rather than as a sink. I studied P sediment-water exchange in two flooded celery fields (west and east), which are designated for wetland restoration, in order to assess the effects that hydrologic reconnection of the area to an adjacent creek would have on P dynamics. We also examined the influence of climate change, specifically warming temperatures, by conducting the sediment-water exchange experiments at ambient and plus 2°C temperature conditions. Lab-based sediment core incubations revealed that TP release …


The Effects Of Invasive Macrophytes Phragmites Australis And Typha Angustifolia On Nitrate Removal In High Nitrate Wetland Sediments, Lauren Mackenzie Beal Apr 2014

The Effects Of Invasive Macrophytes Phragmites Australis And Typha Angustifolia On Nitrate Removal In High Nitrate Wetland Sediments, Lauren Mackenzie Beal

Theses and Dissertations

Constructed wetlands are quickly becoming inundated with invasive species like Phragmites australis and Typha angustifolia which are capable of changing whole ecosystem function and community composition. We wanted to assess how plants affect dissolved oxygen (DO) and dissolved organic carbon concentrations (DOC), and in turn if they increase nitrate (NO3-N) removal rates relative to barren sediments. Using a NO3-N/Br tracer test, we tested NO3-N removal rates, DO, and DOC concentrations. After the tracer test, we measured above- and below-ground plant biomass and sediment characteristics. NO3-N removal did not differ across the treatments. Phragmites australis microcosms had significantly higher sediment bulk …


Effect Of Invasive Phragmites Australis And Its Control On Microbial Community Composition In A Freshwater Wetland, Jennifer K. Kirk Jan 2014

Effect Of Invasive Phragmites Australis And Its Control On Microbial Community Composition In A Freshwater Wetland, Jennifer K. Kirk

Master's Theses and Doctoral Dissertations

Wetlands support great species diversity and perform important ecosystem services like carbon and nutrient cycling, largely facilitated by microorganisms. Invasive plants, like Phragmites australis, reduce biodiversity and alter ecosystem services. I hypothesized that changes in soil bacterial communities would occur after Phragmites invasion and restoration efforts employing herbicide to remove Phragmites would further disrupt communities. This was tested in freshwater wetlands using terminal restriction fragment length polymorphism analysis of PCR amplified eubacterial DNA from soils dominated by Typha and Phragmites vegetation preceding and following herbicide application. Soil bacterial communities differed by vegetation type and indicated both seasonal and inter-annual effects. …