A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy Okaukuejo 1993 / This study was designed to investigate the eco-physiology of baboons (Papio cynocephalus ursinus) in a troop living in the Kuiseb River canyon of the central Namib desert, Namibia. Answers were sought for two major questions: what Were the baboons prospects for survival and were there special adaptations allowing for their survival in their desert environment? To answer the former, life history phenomena of individuals and demographic changes within the troop were studied over a six year period. Results showed that the troop was not self-sustaining. Ectco-parasite infestations killed the majority of infants born to high ranking female baboons, while infant kidnapping by high ranking females killed most lower ranking females' infants. The high infant mortality appeared to affect the behaviour of adult male baboons in the troop, causing non-paternal males to fight harder to maintain a rank with reproductive opportunities, usually with serious wounding or death as a consequence. Answers to the latter question involved investigation into the baboons feeding patterns and diet, body temperature regulation, water flux rates and methods of body water conservation. Despite their desert environment, the baboons had access to plants of high water content and Were not dependent on free water intake. Plant foods also had low electrolyte concentrations. Body temparetures of three free-ranging baboons recorded by intraperitoneal radio tolemeters were remarkably labile, indicating an adaptive heterothermy. The baboons appeared to employ evaporative cooling only when water was available to drink and used cool sub-surface sand to slow their body temperature rises. water flux rates determined using tritiated water of three free-ranging baboons were not different to those of baboons from elsewhere. Acquisition of free water at times of water scarcity was strictly rank related. Body water conservation was apparently achieved through a combination of factors: urine concentration of Kuiseb baboons increased significantly when they were water deprived. The kidneys of the Kuiseb baboons, obtained from baboons that died naturally were anatomically significantly different and head greater urine concentrating abilities than the kidneys Of baboons from the northern Transvaal, South Africa. Kuiseb baboons showed efficient faecal water conservation, similar to other desert adapted mammals, Body water also was apparently conserved by engaging in water conservative behaviour, predominantly inactivity.

Thesis advisor: Noah P. Snyder / Dam-influenced streambank morphology has not been studied extensively in rivers in deglaciated landscapes with high densities of colonial-era milldams. Fluvial restoration in the eastern U.S. often focuses on understanding pre-Colonial floodplain processes. Recent work by Walter and Merritts (2008a) in the Piedmont of the U.S. mid-Atlantic region suggests milldams significantly impact sedimentation by creating surfaces composed of post-dam legacy sediment that are often abandoned by the river and function as fill terraces. I analyze channel morphology and sedimentation patterns upstream of two breached dams on the Sheepscot River in mid-coastal Maine using lidar digital elevation models, historical aerial photographs, radiocarbon dating, and hydraulic modeling. In the past several decades, observable channel morphologic changes occurred at the two study sites: Maxcy's Mills dam (built in 1809, it was 2-m high and breached in the late 1950s), and at Head Tide dam (built in the 1760s, it is 4-m high and was partially breached in 1952). The Sheepscot River has a native population of Atlantic salmon, which is a federally listed endangered species. Understanding the existence and transport of legacy sediment has become an important component of habitat restoration efforts in the region. The goal of this investigation is to determine the extent and morphologic function of legacy sediment in order to better understand how historical dam sites affect channel morphology and sediment transport in a post-glacial, low-gradient river system. Field and remote sensing analyses indicate that surfaces (up to 2.65 m high) composed of mud and sand function as floodplains 1 km upstream from Head Tide dam and surfaces 90 cm high continue 2.5 km upstream from Maxcy's Mills. Analysis of seven radiocarbon dates from pieces of tree bark sampled from the stratigraphy (58-187 cm below the surface) of the two study sites suggest up to 1.8 m of sediment upstream of the two study sites was deposited within the past 300 years and is therefore a legacy of the dams. Quantification of the total volume of stored legacy sediment is on the same scale as volumes observed in the mid-Atlantic Piedmont region, leading to the conclusion that post-glacial rivers in northern New England store milldam sediment in similar fashion to streams analyzed in the Walter and Merritts (2008a) study. / Thesis (MS) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

Thesis advisor: Noah P. Snyder / Emerging methods for acquiring high-resolution topographic datasets have the potential to open new opportunities for quantitative geomorphic analysis. This study demonstrates a technique for rapidly obtaining structure from motion (SfM) photogrammetry-derived digital elevation models (DEMs) using aerial photographs acquired with a small unmanned aircraft system (sUAS). In conjunction with collection of aerial imagery, study sites are surveyed with a differential global position system (dGPS)-enabled total station (TPS) for georeferencing and accuracy assessment of sUAS SfM measurements. Results from sUAS SfM surveys of upland river channels in northern New England consistently produce DEMs and orthoimagery with ~1 cm pixel resolution. One-to-one point measurement comparisons demonstrate sUAS SfM systematically measures elevations about 0.16 ±0.23 m higher than TPS equivalents (0.28 m RMSE). Bathymetric (i.e. submerged or subaqueous) sUAS SfM measurements are 0.20 ±0.24 m (0.31 m RMSE) higher than TPS, whereas exposed (subaerial) points are 0.14 ±0.22 m (0.26 m RMSE) higher than TPS. Serial comparison of DEMs obtained before and after a two-year flood event indicates cut bank erosion and point bar deposition of ~0.10 m, consistent with expectations for channel evolution. DEMs acquired with the sUAS SfM are of comparable resolution but a lower cost alternative to those from airborne light detection and ranging (lidar), the current standard for topographic imagery. Furthermore, lidar is not available for much of the United States and sUAS SfM provides an efficient means for expanding coverage of this critical elevation dataset. Due to their utility in municipal, land use, and emergency planning, the demand for high-resolution topographic datasets continues to increase among governments, research institutions, and private sector consulting firms. Terrain analysis using sUAS SfM could therefore be a boon to river management and restoration in northern New England and other regions. / Thesis (MS) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Geology and Geophysics.

Thesis advisor: Jeremy Shakun / The mechanisms of abrupt climate change during the last glacial period are not yet fully understood. The objective of this research is to use oxygen isotope and magnesium/calcium ratios from foraminifera in a marine sediment core <200 km southeast of New York City (Ocean Drilling Program 174 Site 1073A) to test the hypothesis that changes in freshwater run-off patterns during intermediate extensions of the Laurentide Ice Sheet caused abrupt climate change by disrupting the Atlantic thermohaline circulation. The combination of foraminiferal δ18O and Mg/Ca yields salinity as an isolated variable, which is used as a proxy for Hudson River discharge through ~42,000-28,000 years ago. This thesis reviews the literature on abrupt climate change and compares the Hudson River paleodischarge record to established records of abrupt climate events observed in Greenland ice cores. It concludes that a higher resolution of data points is required to evaluate the impact of Hudson River discharge on abrupt climate change. / Thesis (BS) — Boston College, 2015. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Earth and Environmental Sciences.

Thesis advisor: Noah Snyder / While it has been shown that extensive sedimentation in historic millponds has greatly affected streams in the Mid-Atlantic Piedmont region (Walter and Merritts, 2008), much less is known about the phenomenon in the heavily dammed areas of post-glacial New England. Some research has found similar deposits behind breached historic dams in the Sheepscot River watershed in mid-coast Maine, but at a smaller scale than those seen in the Mid-Atlantic region (Strouse, 2013; Hopkins, 2014). I attempt to further explore millpond sedimentation in New England by quantifying the volume of millpond sediment, also called legacy sediment, in the 171.3 km² upper Charles River watershed in eastern Massachusetts. Twenty three milldams were located in the watershed on 1850s maps, giving a damming density of 0.177 dams/km². Each historic dam that had since breached, 14 in total, was visited in the field to identify possible legacy sediment deposits. Legacy sediments were identified by their meter or higher terraces made of fine sands and silt and verified by comparison to sedimentary patterns found in other legacy sediment deposits and radiocarbon dating of material both within the legacy sediment and in the underlying layer. Legacy sediment terraces with an area of 1.68*10⁴ m² and a total volume of 1.29 - 2.57*10⁴ m³ were found upstream of two adjacent breached historic dam sites on the Charles River in Medway, MA. Radiocarbon dates from a coarse sand and gravel lower at 1.8 m depth returned pre-settlement dates of 1281-1391 cal AD (two σ). These dams were immediately downstream of a large glacial feature with steep banks along the river. The lack of legacy sediment at other dam sites and the lack of sedimentation behind intact dams suggest that a low sediment supply to millponds prevented legacy sediment deposits from forming in most of the watershed. / Thesis (BS) — Boston College, 2016. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Earth and Environmental Sciences.

Thesis advisor: Gail C. Kineke / This study characterizes the bed of the Connecticut River estuary in terms of grain size and bedforms, and relates these to river discharge, tidal currents, and sediment transport. Over four field excursions, sediment cores were collected, in addition to bathymetry surveys, and water column measurements. A three-dimensional circulation and sediment transport model calculated boundary shear stress over the same time. The bed of the estuary is composed mostly of sand, with small amounts of fine sediments. Deposition of fine sediments is limited by the landward extent of the salt intrusion. Large bedforms are oriented seaward. The critical shear stress for the median grain size is exceeded each tidal cycle. Bedload transport is dominantly seaward during high discharge conditions, but varies during low discharge. Bathymetry surveys from previous studies and this study show consistent bedform fields over 25 years. Bedforms observed in the field reflect typical conditions rather than extreme events. / Thesis (MS) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

In the eutrophic waters of the Indian River Lagoon (IRL), decreases in overall shellfish size have been reported, which may be related to coastal acidification. To understand the relationship between acidification and eutrophication, water samples from 20 sites spanning the IRL were collected and analyzed for dissolved nutrients and omega values in spring (dry season) and fall (wet season), 2016-2017. Additionally, three sites were sampled weekly to observe temporal variability of nutrients and omega values. For the IRL-Wide sampling, sites with higher dissolved nutrient concentrations showed lower omega values with significant negative relationships. Both sampling programs showed an overall positive linear relationship between salinity and omega values. This work suggests that salinity and dissolved nutrients have implications for acidification in the IRL and must be considered for future water quality, shellfish and coral reef restoration. / Includes bibliography. / Thesis (M.F.A.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

The non-random selection of medicinal plants theory, which states that phylogeny affects the selection of medicinal plants, was proposed by Daniel Moerman to indirectly prove that traditional medicinal systems are rational and based in part by the therapeutic efficacy of plants. The logic of this theory is that because members of a taxonomical group share similar characteristics, some groups will be more medicinal and will be over-used in pharmacopoeias, while other groups bereft of secondary metabolites and therapeutic potential will be under-used medicinally. To test this theory, Moerman linearly regressed the total number of medicinal plants per family against the total number of plants per family present in an area and examined residual values to find over-used and under-used medicinal plant families. The method has been praised for its simplicity. Nonetheless, shortcomings have been noted and criticized, inspiring researchers to propose new procedures to test for phylogenetic biases in pharmacopoeias. Negative Binomial regression and examination of studentized residuals, the method used in this investigation, ameliorates the original one with a few corrections, conserving the simplicity and solving for all the criticized flaws. Also, this study incorporated different sociodemographic factors to determine if the intracultural homogeneity of traditional knowledge affects the results of the non-random selection of medicinal plants theory analysis. By testing Moerman’s theory, which is one of Ethnobotany’s major theories, this investigation is in agreement with the call to have more hypothesis-driven research within a theoretical framework to continue to advance the Ethnobotany field. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Seagrasses are important foundation species in coastal ecosystems. Genetic diversity of seagrasses can influence a number of ecological factors including, but not limited to, disturbance resistance and resilience. Seagrasses in the Indian River Lagoon (IRL), Florida are considered to be highly disturbed due to frequent events, like algal blooms, that impair water quality, reducing available light for seagrass growth. Halodule wrightii is a dominant seagrass throughout the IRL, but its genetic diversity has only been quantified in a few Gulf of Mexico and Florida Bay populations and little is known about its potential ecological consequences. I quantified the genetic variation of H. wrightii using microsatellite markers in the southern IRL to determine: (i) how disturbance history influenced genetic diversity, (ii) if morphology of clones was, in part, genetically controlled and related to disturbance history, and (iii) if genotypes showed phenotypic plasticity in response to disturbances. In the IRL, H. wrightii populations exhibited moderate genetic diversity that varied with disturbance history. The disturbance history of a population was classified by the variance in the percent occurrence of H. wrightii over a 16-year period. Genotypic richness and clonal diversity of H. wrightii increased with increasing disturbance histories. Other genetic diversity measures (e.g., allelic richness, observed heterozygosity) did not change with disturbance history. These findings suggest that impacts to seagrass coverage over time can change the genotypic composition of populations. When different genotypes of H. wrightii were grown in a common garden, differences in leaf characteristics among genotypes provided evidence that morphological trait variation is, in part, explained by genetic variance. The disturbance history of genotypes did not directly affect morphological traits. However, significant genotype x site (within disturbance history) interactions found greater variation in shoot density and below ground traits of H. wrightii genotypes from sites of intermediate disturbance history. Traits of H. wrightii were shown to be phenotypically plastic. Significant genotype x environment interactions for shoot density and height demonstrated that genotypes responded differently by increasing, decreasing, and not changing sizes in response to light reduction. Genetic diversity of H. wrightii has strong implications for ecological function in coastal communities. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

The goal of this study was to develop an alternative approach to typical seagrass transplantation techniques that damage the donor bed. Floating individuals of Halodule wrightii were collected in the Indian River Lagoon (IRL), Florida, during fall of 2013 and spring of 2014, with the fall collection planted in outdoor tanks. Only 25% of individuals collected in the fall survived the winter in the tanks. Individuals from both collections were deployed onto biodegradable mats in a capped dredge hole in the IRL in March, 2014. Approximately 66% of the mats survived the six-month experiment, and the area covered by seagrass quadrupled. Growth in shoot count, average height, horizontal spread, and biomass was similar for both fall and spring treatments. Thus, time and effort of overwintering had no benefit over spring harvesting. The use of floating individuals can provide a more practical, environmentally friendly alternative to traditional transplanting for seagrass re storation. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection