The South African National Water Act (NWA) (No. 36 of 1998) recognises that in order to sustain the goods and services that are provided by rivers and their associated biological communities, it is necessary to conserve the entire aquatic ecosystem. Conservation and maintenance of ecosystem functioning entails the protection of the biotic components (i.e. fish, macroinvertebrates, riparian vegetation, etc.) and ensuring that the abiotic driver aspects (i.e. required amount and variability of flow, water quality and fluvial geomorphology) are addressed and met (Malan and Day, 2003). According to the Reserve Determination methodology (DWAF, 2003), sustainable utilisation of the river resources requires proper, responsible management and that exploitation without understanding or limits, impacts negatively on the ecological processes, functions and communities, both in the present and the future. Manipulation of the flow regimes of rivers, to provide water when and where people need it, has resulted in a growing deterioration in the condition (health) of riverine ecosystems (King et al., 2000). Stressors on aquatic ecosystems originating from these anthropogenic activities, include point and non-point loadings, land use influences and changes, and stream modification. These are usually defined by the drivers of aquatic ecosystems namely the geomorphology, hydrology and water quality. In turn, the effects on the physical habitat and water quality have both direct and indirect effects on the biotic communities present and are usually defined by biological responses to these changes (Kleynhans et al., 2005). There is currently limited data available to formally propose a methodology to quantify the significance of altered flows in riverine ecosystems brought about by the abstraction or excessive release of water by industrial activities on a reach scale. The aim of this study was to determine the degree and magnitude of habitat-flow alterations caused by pulp and paper mill activities in the Elands and Mvoti Rivers and to link the related biological responses to them. / Prof. V. Wepener

Ph.D. (Zoology) / Due to the excessive utilisation of the ecological services of surface aquatic ecosystems in South Africa, the integrity state of these systems continues to decline resulting in the loss of key ecosystem services. This trend suggests that the national requirements to maintain a sustainable balance between the use and protection of these systems are not being met. In an attempt to address this status quo, all stakeholders of these systems need to become more closely engaged in the social and institutional decision making processes to manage these systems. Management plans need to be integrated and take a wide range of conservation and use objectives for specific ecosystems into account. Furthermore, approaches need to allow for the assessment of multiple stressors that have synergistic effects, while the unique characteristics of the ecosystem taken into consideration. Risk assessments entail assigning magnitudes and probabilities to hazards or anthropogenic activities or natural catastrophes that have adverse effects m ecosystems. In these assessments the existence of a hazard and the related uncertainty of its effects results in the formulation of risk. An Ecological Risk Assessment is a structured approach that describes, explains and organises scientific facts, laws and relationships, thereby providing a sound basis to develop sufficient protection measures for the environment, which facilitates the development of utilisation strategies for the environment. A Regional Scale Risk assessment using the Relative Risk Model (RRM) is a form of Ecological Risk Assessment that is carried out on a spatial scale where considerations of multiple sources of multiple stressors affecting multiple endpoints are allowed. The use of the RRM also allows for the characteristics of the landscape that may affect the risk estimate to be considered. This study is based on a research hypothesis that the RRM is a suitable water resources management tool that can address the risk assessment of multiple stressors in South African freshwater environments. To test this hypothesis this study aims to contextualise the RRM methodology within the current water resources management practices in South Africa and demonstrate the applicability of RRM within the South African water resources management framework. The applicability of the RRM will be tested using two case study regions. The case studies are the Elands River and its associated ecosystems in the upper Crocodile River catchment in Mpumalanga and the entire catchment of the Umvoti River in KwaZulu-Natal

In recent history, C. jamaicense has been displaced by another native monocot, T. domingensis, predominantly resulting from increased phosphorous enrichment in the Everglades. This study aimed to elucidate these two species responses to low and high [Pi] in terms of allocation, photosynthate partitioning and growth. C. jamaicense growth was independent of Pi, while T. domingensis growth increased with [Pi]. Under high [Pi], allocation to younger T. domingensis shoots occurred, while C. jamaicense shoots retained more [Pi], while low [Pi] resulted in homogeneous allocation patterns for both species. Additionally, Pi deficiencies induced carbohydrate levels in older shoots of T. domingensis, while [Pi] had no effect on photosynthate partitioning patterns in C. jamaicense. ACP activity was induced by Pi deficiency in all T. domingensis shoots and increased with shoot age, while no effect was observed in C. jamaicense. Results indicate these two species differ in allocation strategies when [Pi] is altered. / by Brian Hill. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Loggerhead (Caretta caretta) and green (Chelonia mydas) turtles recruit to nearshore environments as juveniles. These often degraded habitats are associated with emerging diseases such as green turtle fibropapillomatosis (GTFP), however there are few studies on immune function in sea turtles. The objective of this research was to quantify phagocytosis of the innate immune system by flow cytometry and compare levels between animals from a degraded habitat (the Indian River Lagoon, FL) to a more pristine environment (the Trident Basin, Port Canaveral, FL), and across a range of temperatures. While in vitro temperatures did not alter rates of phagocytosis, it was higher in samples obtained in the summer than winter. Rates of phagocytosis in sea turtles with GTFP and from degraded environments with increased prevalence of GTFP were low compared to animals from the more pristine environment, suggesting that the environment can alter innate immunological function and thus contribute to the development of disease. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Changes in vegetation may influence the quality and quantity of the underlying organic peat soils and have impacts on faunal populations. My goal was to determine whether shifts from native slough communities to invasive cattail in the Florida Everglades could affect peat characteristics that could cascade to impact the dry season survival of crayfish (Procambarus fallax). I contrasted peat soils from native slough and cattail-invaded sites as alternative dry-season burrowing substrates for crayfish. Cattail peat had higher average bulk density and inorganic content within the first ten centimeters of the soil profile. Crayfish showed marginally greater initial burrowing success in slough peat than in cattail peat but survival was equivalent in both peat soils and high overall. Understanding these indirect linkages between vegetation and crayfish populations in the Everglades can provide insight on the consequences of plant invasion on ecosystem trophic dynamics. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

In recent decades, ecohydrology has received renewed attention because of the impacts of groundwater withdrawal on ecosystems. Growing population and urban expansion in Palm Beach County, FL. place pressure to eradicate natural areas, such as Florida scrub habitats, and increase groundwater withdrawal. This study presents preliminary results of soil and hydrological characterization of an ecological preserve surrounded by changing land use. Soil moisture and water levels were monitored to assess the effects of precipitation as influenced by plants and soil analysis determined the suitability of current soil conditions for hosting native vegetation habitats. Hydrologic and soil conditions on the preserve fall within values expected for native Florida scrub habitats. Hydrologic response to precipitation varied due to factors including antecedent conditions and vegetation types. These results provide a better understanding of the interactions between soil proper ties, hydrologic cycle, and plants, and assist with establishing a baseline to monitor changes over time. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

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.

Fish predation can have structuring effects in aquatic communities, but the most important fish predators are not always immediately obvious. Generalist fish predators often occupy similar habitats and consume similar prey making determination of their consumptive impacts difficult. Understanding these consumptive impacts is important for understanding complex wetland food webs. I collected warmouth (Lepomis gulosus), bluespotted sunfish (Enneacanthus gloriosus), and dollar sunfish (Lepomis marginatus) in two seasons from sloughs for both diet and bioenergetics analysis. Macroinvertebrates dominated diets of the three species, and nonparametric analyses revealed evidence of diet ontogeny in warmouth and potential competition for prey items among gape-matched individuals. Bioenergetics modeling revealed high levels of macroinvertebrate comsumption by these species relative to macroinvertebrate reproductive output suggesting that when combined with other sources of mortality, consumptive pressures placed by sunfish on benthic macroinvertebrates may be quite large. / by Jacob Bransky. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Notions of ‘wildness' are increasingly relevant to upland management discussions in the Scottish Highlands as several conservation-focused estates embrace a ‘wildland management ethos'. However, while a range of wildland conservation initiatives have embarked upon pathways towards ‘rewilding', this research demonstrates that, although members of this creative conservation movement are widely perceived to share a common vision, they prioritise markedly different wildland qualities. Through a series of triangulated phases, this research explores this ‘spectrum of wildness' and examines the conceptual coherence of wildland restoration discourses. Twenty semi-structured scoping interviews with key stakeholders associated with Scotland's wildest places provide the foundations for an adapted Delphi model, incorporating a Q-methodology study, which utilises insights from seventeen large upland land-holdings to interrogate the disparate discourses associated with Scotland's emergent wildland movement. A taxonomy of management approaches is presented based upon (i) different conceptions of ‘wildness', (ii) differing degrees of concern for ecological and cultural integrity, (iii) conflicting beliefs about the degree of management intervention appropriate and (iv) fundamentally divergent underlying environmental ideologies. A further twenty-three semi-structured interviews exploring wilderness restoration frameworks in the USA, New Zealand and parts of Europe provide an international perspective on Scotland's distinctive approach to wildland management and demonstrate the challenges of multi-dimensional wilderness frameworks which grow out of conflicting mandates; most notably, a critical faultline exists between restoring ‘wildness' (focussed on processes) and naturalness (focussed on endpoints). Given that practical tensions can arise from these different ideological perspectives, understanding and accommodating the social and cultural dimensions which shape multiple (re)wilding discourses is considered critical. As such, place-specific and endogenous social representations are called for, in which wild land is both a physical place and a cultural ideal, and in which (re)wilding comprises a heterogeneous mix of different wilds. This research also critically reflects upon how cultural landscapes with wild qualities present opportunities for rethinking the historical and cultural dimensions of established wilderness values. By exploring the framing of ‘wild' in Scotland's wildland initiatives, a postmodern wildlands narrative which negotiates the conceptual challenges of (re)wilding in a storied, cultural landscape is presented.

Este trabalho é fruto de uma investigação realizada junto Programa Educom.rádio, curso de extensão oferecido pelo Núcleo de Comunicação e Artes da USP a aproximadamente 11 mil professores e alunos de 455 escolas da rede municipal de ensino da cidade de São Paulo, entre 2001 e 2004, tendo como foco a maneira como o conceito e a prática do planejamento foram considerados tanto na elaboração do projeto quanto como conteúdo previsto no cronograma de atividades. Além da descrição das formas sob as quais o tema do planejamento esteve presente ao logo do desenvolvimento do curso, foram analisados especificamente a produção de 169 propostas de planejamento educomunicativo de autoria conjunta de professores, alunos e membros da comunidade que participaram de duas das sete fases do Educom.rádio, respectivamente a 6ª e a 7ª fases. O resultado da pesquisa possibilita afirmar não apenas que o planejamento é um requisito fundamental para garantir o sucesso de qualquer trabalho educomunicativo, como atesta o esforço de coerência epistemológica do próprio do projeto para garantir sua coerência interna, entre o que ensinou e o que praticou, enquanto atividade cultural e educativa. / This paper is the result of a research program conducted with Educom.rádio, extension course offered by the Center for Communication and Arts of USP to approximately 11 thousand students and teachers of 455 schools in the municipal system of education in the city of São Paulo, between 2001 and 2004, focusing how the concept and practice of planning were both in the preparation of the project as content as specified in schedule of activities. Besides the description of the ways in which the subject of planning was right to the development of the course, have been examined specifically the production of 169 proposals for planning educomunication of joint authorship of teachers, students and community members who participated in two of the seven stages the Educom.rádio respectively the 6th and 7th phases. The search result provides not only to say that planning is a prerequisite for the success of any work educomunicating, as evidenced by the effort of the epistemological consistency by design to ensure internal consistency, and what it taught and practiced as cultural and educational activity.