Seasonal variation in food availability is one of the primary limitations to avian populations, particularly during the breeding season. However, the behavioral responses between species may differ based on foraging strategies. I examined the influence of food availability on landscape-level habitat selection, patch-level habitat selection, and movements of two wading bird species with divergent foraging strategies, the Great Egret and White Ibis. On a landscape scale, there appeared to be a relationship among resource availability, the temporal scale of the independent variable, and whether the response was similar or different between species. At the patch level, results demonstrated a relationship between resource availability and the spatial scale of the independent variables selected by birds. Species movements were consistent with the differing strategies. This study is the first to make the link between landscape hydrology patterns, prey availability, and responses in wading bird habitat selection at multiple spatial scales. / by James M. Beerens. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

Successful foraging by avian predators is influenced largely by prey availability. In a large-scale experiment at the Loxahatchee Impoundment Landscape Assessment project within the Arthur R. Marshall Loxahatchee National Wildlife Refuge, I manipulated two components of prey availability, water depth and vegetation density (submerged aquatic vegetation and emergent vegetation), and quantified the response by wading birds in terms of foraging habitat selection and foraging success. Manly's standardized selection index showed that birds preferred shallow water and intermediate vegetation densities. However, the treatments had little effect on either individual capture rate or efficiency. This was a consistent pattern seen across multiple experiments. Birds selected for certain habitat features but accrued little benefit in terms of foraging success. I hypothesize that birds selected sites with shallow water and intermediate vegetation densities because they anticipated higher prey densities, but they did not experience it here because I controlled for prey density. / by Samantha Lantz. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

Wetlands in the United States have been decreasing in number from the time European settlers began draining them for agricultural purposes to the present. Wetlands serve many important ecological functions such as waterfowl habitat.The purpose of this project was to investigate wetland creation literature in order to develop a process which could be applied to a particular site to attract waterfowl. The topics reviewed for this project were goal setting, for wetland creations, wetland creation methodologies and waterfowl habitat criteria. The major portion of the project was devoted to the construction process of the wetland. The criteria used to direct the wetland construction were hydrology, topographic contour design, revegetation, and protective buffers. Trail development to provide public access for educational purposes was also an important component of the wetland design. Waterfowl habitat criteria was also researched and applied to the project in order it insure that waterfowl would be attracted to the wetland.The process developed from the research was applied to Jim Haberek's property located in Anderson, Indiana. The product was a masterplan which included a site analysis, a water level management plan, a contour design, a revegetation plan, protective buffers and a trail design for the public. / Department of Landscape Architecture

Dissertation (PhD)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Constructed wetlands have been widely used in the treatment of industrial and domestic wastewater to reduce biological and chemical oxygen demand (BOD and COD), to remove nitrate and enteric viruses as well as to generally improve water quality. Distillery wastewater has a complex character due to high concentrations of sugars, lignins, hemicellulose, dextrins, resins, polyphenols and organic acids, leading to a high COD that may exceed 100 000 mg/L. The potential application for the treatment of distillery wastewater by means of constructed wetlands is relatively unexplored. In 1999 a study was initiated at Distell Goudini distillery, Western Cape, South Africa, to explore the possibility of using constructed wetlands to treat distillery wastewater. It was found that constructed wetlands do have the ability to treat distillery wastewater providing that the influent COD does not exceed 15 000 mg/L for extended periods and the correct substrate material is used. The present study expanded on the above-mentioned study and specifically aimed to provide information on the microbiological controls in wetland systems in an applied sense that may contribute to improved treatment efficiency. Furthermore, this project aimed to contribute to our fundamental understanding of the microbial ecology of constructed wetlands used for the treatment of distillery wastewater. This study revealed that a highly dynamic microbial composition exists within wetlands. Furthermore it was found that wetlands can efficiently remove COD even though a low degree of similarity exists between microbial communities in various zones of the same wetland and those between different wetlands, as well as low similarity between communities sampled from the same zone over time. This demonstrates that it will be difficult to define the ‘ideal’ degradative community in terms of microbiological criteria and serves as a reminder that various indicators should be considered for monitoring system health. Furthermore the shifts in microbial community composition illustrate the ability of microbial communities to adapt to changes in the environment without compromising their functional efficacy. When studying the attached microbial communities within wetland systems it was found that different morphotypes are detected at certain stages of biofilm development while some organisms are present at most phases of biofilm formation. Measurement of CO2 production and dissolved organic carbon (DOC) removal in laboratory scale columns showed that grazing protists had a notable effect on overall microbial activity and that organic loading influenced these predator-prey interactions. Interestingly, increased clogging of pores occurred in the presence of protists, resulting in reduced flow through the porous matrix. Terminalrestriction fragment length polymorphism (T-RFLP) analysis of biofilms on gravel in experimental wetlands indicated that the presence of protists and algae had an effect on the microbial community composition. Scanning electron microscopy (SEM) showed that the presence of algae also had an influence on biofilm structure suggesting that the algae provided labile nutrients that were utilized by the bacterial and yeast members of the community. Finally, augmentation with a commercial mixture or microbial populations isolated from distillery effluent demonstrated that the concentration at which supplements are applied influence degradative efficiency. / AFRIKAANSE OPSOMMING: Kunsmatige vleilande word wêreldwyd gebruik in die behandeling van indusriële en huishoudelike afvalwater om biologiese en chemiese suurstof aanvraag (BSA en CSA) te verminder, om nitrate en ingewandsvirusse te verwyder asook om waterkwaliteit in die algemeen te verbeter. Distilleerafvalwater het komplekse eienskappe as gevolg van hoë konsentrasies suiker, lignien, hemisellulose, dekstrien, harpuis, polifenole en organiese sure, wat lei tot ‘n hoë CSA wat 100 000 mg/L kan oorskry. Daar is tot op hede relatief min studies gedoen oor die potensiële gebruik van kunsmatige vleilande vir die behandeling van distilleerafvalwater. In 1999 is ‘n studie by Distell Goudini distilleeraanleg in die Wes Kaap van Suid Afrika onderneem om die moontlikheid van kunsmatige vleilande vir die behandeling van distilleerafvalwater te bestudeer. Daar was bevind dat kunsmatige vleilande die vermoë het om distilleerafvalwater te behandel gegewe dat die invloeiende CSA nie 15 000 mg/L oorskry nie en dat die regte substraat materiaal gebruik word. Die huidige studie het by die bogenoemde studie aangesluit met die doel om informasie oor die mikrobiologiese kontroles in vleilandsisteme op ‘n toegepaste wyse te voorsien, wat tot verbeterde behandeling doeltreffendheid kan lei. Hierdie studie het verder beoog om by te dra tot ons fundementele kennis van die mikrobiese ekologie van kunsmatige vleilande wat gebruik word vir die behandeling van distilleerafvalwater. Dié studie het bevind dat daar ‘n hoogs dinamiese mikrobiese samestelling binne vleilande bestaan. Daar was verder bevind dat CSA steeds effektief deur vleilande verwyder kan word alhoewel daar ‘n lae graad van ooreenstemming is tussen mikrobiese gemeenskappe in verskeie sones van dieselfde vleiland en verskillende vleilande, asook ‘n lae graad van ooreenstemming tussen gemeenskappe wat in dieselfde sone oor tyd gemonster is. Dit demonstreer dat dit moeilik sal wees om die ‘ideale’ degraderende gemeenskap te vind in terme van mikrobiologiese kriteria en dien as ‘n herinnering dat verkeie indikatore in ag geneem moet word om die welstand van ‘n ekologiese sisteem te monitor. Die verskuiwings in mikrobiese gemeenskapsamestelling illustreer verder die vermoë van natuurlike sisteme om aan te pas by veranderinge in die omgewing sonder om funksionele doeltreffendheid te verminder. Die studie van aangehegte mikobiese gemeenskappe het aangedui dat veskillende morfotipes bespeur kan word tydens sekere fases van biofilm formasie terwyl sekere organismes tydens meeste van die fases teenwoordig is. Die bepaling van CO2 produksie en die verwydering van opgeloste organiese koolstof in laboratoriumskaal kolomme het geïlustreer dat voedende protiste ‘n waarneembare effek gehad op die algehele mikrobiese aktiwiteit en dat die organiese lading hierdie predator-prooi interaksie beïnvloed het. Dit was interessant om te vind dat die teenwoordigheid van protiste die verstopping van porieë aangehelp het en dus tot verlaagde vloei deur die poreuse matriks gelei het. Terminale-restriksie fragment lengte polimorfisme (T-RFLP) analiese van biolfilm op klipgruis in eksperimentele vleilande het aangedui dat die teenwoordigheid van protiste en alge ‘n effek gehad het op die mikrobiese gemeenskapsamestelling. Skandeerelektronmikroskopie (SEM) het bewys dat die teenwoordigheid van alge ook ‘n invloed op biofilm struktuur gehad het wat daarop dui dat alge maklik afbreekbare voedingstowwe aan die bakterieë en giste van die mikrobiese gemeenskap beskikbaar gestel het. Laastens was bewys dat die konsentrasie van toevoeging van ‘n kommersiële mikrobiese mengsel of mikrobiese populasies wat uit afvoer geïsoleer was, die effektiwiteit van degradering kan beïnvloed.

published_or_final_version / Zoology / Doctoral / Doctor of Philosophy

The Tonle Sap is the largest and most important natural wetland in Southeast Asia. It covers an area of more than 15,000 km2 with a unique mosaic of natural and agricultural floodplain habitats that coexist with the largest fishery in the Mekong Basin. Accelerating hydropower development and climate change, however, are altering the Mekong’s hydrology, which could negatively affect downstream ecosystems. The Tonle Sap is facing a two-fold problem. First, the link between its hydrology and ecosystem properties is not well understood. Second, potential ecological changes caused by future hydrological disruptions related to hydropower and climate change are unknown. Thus, the main objective of this thesis was to quantify how alterations to the Mekong hydrology could affect the Tonle Sap ecosystem. The following studies were performed to addressed the objective: (1) an assessment of landscape patterns using geographical information and remote sensing tools; (2) an assessment of habitat patterns based on field surveys of water, vegetation, and soils; (3) ecosystem function modelling to simulate net primary production (NPP) as a function of water quantity, sediments, and habitat type; and (4) fauna habitat modelling linking the results from the assessment of landscape patterns to fauna species. The assessment of landscape patterns revealed a distinct relationship between inundation and vegetation. Habitats in the Tonle Sap were divided into five groups based on annual flood duration, as well as physiognomic factors and human activity: (1) open water, (2) gallery forest, (3) seasonally flooded habitats, (4) transitional habitats, and (5) rainfed habitats. Large habitat shifts could occur as a result of hydropower development scenarios by the 2030s; areas optimal for gallery forest could decrease by 82% from baseline conditions, whereas areas of rainfed habitats could increase by 10-13 % (813-1061 km2). The assessment of habitat patterns demonstrated that despite the complexity and intense human use of this ecosystem, the flood-pulse is the underlying driver of habitat characteristics by (1) determining inundation depth and duration; (2) creating the main soils gradient; (3) limiting the area cleared for agriculture; (4) influencing vegetation structure and water quality; and (5) shaping the composition of plant species. The ecosystem function model was used to estimate a reduction of 9-39% in annual NPP caused by different scenarios of hydropower development and/or climate change during 2032-2042. Cumulative impacts from hydropower would disrupt NPP to a greater extent than climate change. The fauna habitat model revealed that species richness was greatest in the gallery forests and seasonally flooded habitats. Animals that permanently reside in or that rely on these habitats to complete essential life-history stages would be the most affected by future changes. This thesis provides the first quantitative formulation that directly links fundamental components of the Tonle Sap ecosystem to its flood-pulse hydrology. It also provides a comprehensive assessment of the impacts of expected hydrological alterations. Hydropower is expected to bring more abrupt and distinct ecological alterations than climate change in future decades. Relative aerial changes to the gallery forests are expected to be greater than in other habitats. A decline of the Tonle Sap’s ecosystem services will occur if appropriate measures are not implemented. These measures include mitigating hydropower alterations, conserving natural habitats in areas that are likely to remain hydrologically undisturbed, restoring natural habitats in projected areas for optimal growth, and optimizing agricultural practices in the floodplain. Research findings from this thesis focused on the Tonle Sap, but given the fundamental commonalities between this system and other large floodplains, the information presented is highly informative to other large flood-pulse driven systems around the globe.

U.S. Army Corps of Engineers (USACE) regulates fill of jurisdictional waters of the United States including wetlands. Recent USACE regulations set a threshold of impacts to wetlands at one-half acre. Impact area can be determined by Global Positioning System (GPS) measurement of wetland boundary and Geographic Information System (GIS) calculation of impact area. GPS point selection methods include (1) equal time interval, (2) transect and (3) intuition. Four two-acre shapes were measured with each GPS method and brought into GIS for area calculation. Analysis of variance and Root Mean Square Error analyses determine that the transect method is an inferior point selection method in terms of accuracy and efficiency.

Peat soils are known to be a significant source of atmospheric greenhouse gasses. However, the releases of methane and carbon dioxide gasses from peat soils are currently not well understood, particularly since the timing of the releases are poorly constrained. Furthermore, most research work performed on peatlands has been focused on temperate to sub-arctic peatlands, while recent works have suggested that gas production rates from low-latitude peat soils are higher than those from colder climates. The purpose of the work proposed here is to introduce an autonomous Ground Penetrating Radar (GPR) method for investigating the timing of gas releases from peat soils at the lab scale utilizing samples originating from Maine and the Florida Everglades, and at the field scale in a Maine peatland. Geophysical data are supported by direct gas flux measurements using the flux chamber method enhanced by timelapse photography, and terrestrial LiDAR (TLS) monitoring surface deformation. / by William J. Wright. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Trade-offs in traits conferring success in permanent and ephemeral habitats are often at odds with few species being able to persist in both types of environments. I examined the effect of sunfish predators on two species of south Florida crayfish to establish the mechanism that limits one species, Procambarus alleni, to short-hydroperiod environments. The crayfish assemblage response to a gradient of sunfish predators and the effect of predation on P. fallax alone was examined. I also examined the effects of sunfish on crayfish growth and quantified activity levels and risky behaviors of both crayfish species. P. alleni dominated at low sunfish densities but dominance shifted with increasing sunfish density. P. alleni was more active and likely to initiate risky behaviors, suggesting that sunfish predators remove the more active P. alleni, reducing their numbers disproportionally to those of P. fallax and allowing P. fallax to dominate crayfish assemblages in long-hydroperiod wetlands. / by Christopher M. Kellogg. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Variation in the seasonal water level fluctuations of tropical and subtropical wetlands controls the production and concentration of aquatic fauna that support breeding wading birds. However, little is known about how particular components of the annual hydrologic cycle affect processes that control food availability and reproduction. This thesis identifies specific mechanisms responsible for transforming wet season prey standing stock into dry season prey concentrations, links landscape hydrological patterns to wading bird nesting, and presents a predictive model of Wood Stork nesting. I examined the supoort for several a priori hypotheses of factors affecting wading bird prey concentrations and wading bird nest effort. Factors affecting the concentration and vulnerability of prey were important for transferring secondary production to higher trophic levels. Receding water levels, microtopographic variation, and high standing stocks of prey were critical for generating pulses of food availabiltiy to meet the high energy requirements of breeding predatory birds. / by Bryan A. Botson. / Thesis (M.S.)--Florida Atlantic University, 2012 / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.