Coral reefs have one of the highest levels of biodiversity of all ecosystems in the world and are important for both human livelihood and food security throughout many tropical countries. However, due to increased anthropogenic pressure on marine ecosystems, especially during the last couple of decades, coral reefs have become critically over-fished, and many reefs are now in a degraded state and are facing additional future threats due to further over-exploitation, chemical pollution, sedimentation, and effects of climate change. The main aim of this PhD thesis was to understand effects of anthropogenic disturbances on tropical coastal ecosystems and fish connectivity for coastal management purposes. Therefore, linkages between anthropogenic disturbance and corals were investigated (Paper I), as well as interactions between coral reef habitat and associated fish assemblage (Paper II). Furthermore, connectivity between coral reefs and other tropical coastal ecosystems was explored (Paper III), as well as fish migration to reproduction sites (Paper IV), and evaluations of spatial ecology methods (Paper V). The result showed that coral reefs that are already exposed to disturbances, such as freshwater and nutrient run-offs, may be more sensitive to climate change, in terms of increased sea surface temperatures (Paper I). In addition, there were also clear linkages between coral reef quality, in terms of coral coverage, and fish assemblages, which displayed high spatial variability and suggesting patchy recovery after the 1997/1998 bleaching and subsequent coral mass mortality event (Paper II). This highlights the importance of understanding effects of disturbances on corals, especially in terms of synergistic effects between increased water temperatures and other coastal stressors such as decreased salinity and increased nutrients; and the indirect effects of habitat degradation on the fish community. Linkages between fish and different coastal habitats were further explored. The results showed that coral reefs were strongly connected with mangrove and seagrass beds, through ontogenetic migration of fish (Paper III). Migrations to spawning sites of groupers were related to lunar activities when thousands of fish gather for reproduction purposes during new moon, which increases the risk of over-exploitation (Paper IV). The results emphasises the importance of protecting key areas such as nursing grounds and reproduction sites. Furthermore, acoustic telemetry has become an increasingly common method in studies of fish movement, and the results showed that efficiency of acoustic arrays may increase depending on deployment strategies and habitat characteristics (Paper V). In conclusion, the results from this PhD thesis emphasises the importance of protecting coral reef habitats, as well as identifying related susceptible tropical coastal areas, such as nursing grounds and reproduction sites. Indeed, a better scientific understanding of coral reef ecology and indirect and direct effects on fish assemblages are needed for efficient and accurate coastal management decisions. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Manuscript.</p>

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / The objective was to assess the changes promoted in the stocks and flows of C and N from the soil by farming systems agroforestry (agrosilvipasture - AGP and silvipasture - SILV) and traditional (TR), compared to natural vegetation of Caatinga (VN), after 13 years, the experiment was installed on a typical Ortic Chromic Luvisol, the city of Sobral, CearÃ. Soil samples were collected at depths 0-6, 6-12, 12-20, 20-40 and 40-60 cm, relief in four replicates per. Was determined by the total carbon carbon (TOC); total nitrogen (NT) and bulk density. The gas flow was measured using an analyzer in the field of O2, CO2, NO / NO x and SO 2 (UNIGAS Eurotron 3000). To this end, were used for still cameras based on galvanized steel and PVC cover installed in the field. The sampling was done in three replicates, considering the relief plan, convex and concave in each study situation. For each determination were performed triplicate, totaling nine chambers for relief. Soil samples were collected for determination of soil bulk density (Ds) and particle (Dp) and gravimetric moisture (Ug), which allowed the calculation of total porosity (Pt) and the pore space filled with water (EPPA). Among the agroforestry systems studied, the silvipasture, long-term, promoted greater reductions in C stocks and N, the system promoted agrossilvipastroil lower losses and represents a sustainable alternative to sequestration of soil C and N in the Brazilian semi-arid conditions. The traditional cropping system provided a reduction of 58.87 and 9.57 (Mg ha-1), which meant, a reduction of 6.5 and 1.06 (Mg ha-1), for those of TOC and TN, respectively. These results demonstrate the inadequacy of this system for the Brazilian semi-arid conditions. The concave topography (AGP) and flat (SILV) showed the highest values of TOC. For NT the concave shape (VN, AGP, and SILV) showed the highest values. Flows of C-CO2 varied with the time, AGP and SILV being similar to NV in the wet season, while in the dry season are higher. The TR has a different behavior, being higher during the wet season and similar to AGP and SILV in the dry. The flow behavior of NO present without a tendency similar to C-CO2: AGP and SILV presents similar to each other in the wet season, but smaller than VN. During the dry SILV and VN are larger than AGP. In TR NO was not detected in the two periods. The convex shape of relief TR system showed the highest values of C-CO2 fluxes in the wet season. In the dry season were found higher values of C-CO2 flows in AGP, SILV and RT, compared to NV flat terrain. Soil moisture was the variable most correlated with the fluxes of NO, what might be observed in systems SILV and AGP and VN convex reliefs. / Objetivou-se avaliar as alteraÃÃes promovidas nos estoques e fluxos de C e N do solo por sistemas agrÃcolas agroflorestais (Agrossilvipastoril â AGP e Silvipastoril â SILV) e tradicional (TR), comparativamente à vegetaÃÃo natural de Caatinga (VN), apÃs 13 anos, em experimento instalado sobre um Luvissolo CrÃmico Ãrtico tÃpico, no municÃpio de Sobral, CearÃ. Amostras de solo foram coletadas nas profundidades de 0-6, 6-12, 12-20, 20-40 e 40-60 cm, em quatro repetiÃÃes, considerando os relevos plano, convexo e cÃncavo em cada situaÃÃo de estudo. Nestas amostras foram determinados o carbono orgÃnico total do solo (COT), nitrogÃnio total (NT), densidades do solo (Ds) e de partÃcula (Dp) e a umidade gravimÃtrica (Ug), o que possibilitou o cÃlculo da porosidade total (Pt) e o espaÃo poroso preenchido por Ãgua (EPPA). O fluxo dos gases foi quantificado no campo utilizando um analisador de O2, CO2, NO/NOX e SO2 (UnigÃs Eurotron 3000). Para tanto, foram utilizadas cÃmaras estÃticas com base de aÃo galvanizado e tampa de PVC instaladas no campo em triplicatas, totalizando nove cÃmaras por relevo. Entre os sistemas agroflorestais estudados, o silvipastoril, em longo prazo, promoveu maiores reduÃÃes nos estoques de C e N, enquanto que agrossilvipastoril promoveu menores perdas, representando uma alternativa sustentÃvel para o sequestro de C e N do solo nas condiÃÃes semiÃridas brasileira. O sistema de cultivo tradicional (TR) apresentou reduÃÃo no perÃodo 13 anos de 58,87 e 9,57 Mg ha-1 (6,5 e 1,06 Mg ha-1 ano-1) dos estoques de COT e NT, respectivamente, o que comprova a nÃo adequaÃÃo deste sistema para as condiÃÃes semiÃridas brasileiras. Os relevos cÃncavo (AGP) e plano (SILV) apresentaram os maiores valores de estoques de COT, enquanto que para o NT, a forma cÃncava apresentou os maiores valores, no caso VN, AGP e SILV. Os fluxos de C-CO2 variaram com a Ãpoca, sendo AGP e SILV semelhantes à VN no perÃodo Ãmido, enquanto no perÃodo seco estes mesmos sistemas foram maiores. O TR apresenta comportamento diferenciado, sendo maior no perÃodo Ãmido e semelhante ao AGP e SILV no seco. Os fluxos de NO apresentaram comportamento com tendÃncia diferente do C-CO2: AGP e SILV apresentaram-se semelhantes entre si no perÃodo Ãmido, porÃm menores que VN. No perÃodo seco, SILV e VN foram maiores que AGP. No TR, o NO nÃo foi detectado nos dois perÃodos. O relevo convexo no TR apresentou os maiores valores de fluxos de C-CO2 no perÃodo Ãmido. No perÃodo seco foram encontrados maiores valores de fluxos de C-CO2 em AGP, SILV e TR em relaÃÃo à VN no relevo plano. A umidade do solo foi a variÃvel que mais se correlacionou com os fluxos de NO, o que pÃde ser observado nos sistemas SILV e AGP e na VN relevos convexos.

This dissertation reviews the principles of International River Basin Management and their application by the governments of Angola, Botswana and Namibia. The dissertation deals with the issues popularised by governments, water planners and international agencies that the twenty-first century's conflicts will be fought over water. Increasingly this concern is being used to justify new water-supply dams and river diversion projects. This is especially so in arid Southern Africa, the focus of this dissertation, where numerous major international water transfers are underway and many more are being planned. While Namibia's growing thirst is a serious problem, the story is more complicated than just too many basin states putting their straws into one glass. The growing conflicts over the Okavango's water use raise broader questions about ownership of common resources, and equity of access to those resources. Most southern African countries depend on primary natural resources to sustain economies and their people. The environmental issues are remarkably similar in countries within the region, and the economic, social and political fortunes of the individual countries are intertwined. Furthermore, the ways in which resources are being managed are similar and thus cause for common concern. In general, the ability of countries in the region to achieve sustainable development depends not on national policies but also on the commitment of neighbours to practice sound environmental management. This is because activities in one country can easily cause impacts on a neighbour and possibly result in "downstream" opportunity costs. This case study of the Okavango River Basin, a river facing prospective developments from riparian states Angola, Botswana and Namibia, attempts to find sustainable solutions to solving international resource conflict. In addition to outlining the possible future threats to the Okavango River, this study proclaims a number of recommendations in the way of declaring alternatives to Namibia's plans to extract water from the Okavango River. One such recommendation is the encouragement of Water Demand Management as an alternative to water transfer by Namibia. This management strategy is aimed at optimising the use of available water rather than developing new or extended supplies and as a result it has a vital role to play since it contributes to sustainable development rather than over exploitation of limited natural resources. The majority of large rivers in the Southern African Development Community (SADC) are shared by three or more countries, and as the region's water resources come under growing development pressure, the importance of establishing effective national and regional methods and institutions for sustainably managing these resources will increase greatly. From economic, ecological and human welfare perspectives, the Okav,ango River Basin is arguably one of the most important transboundary natural resources (TBNR) in the region. Owing to the basin's remoteness and history of conflict, the Okavango was spared much of the destructive developments that rivers in the region have suffered. As a result, the relatively pristine Okavango ecosystem continues to provide significant benefits to the region much as it has done for centuries. As we approach the new millennium, however, it is clear that the health of the Okavango River Basin is threatened as riparian states increasingly turn to the Okavango to support their growing populations and economies. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2002.

Using a comparative approach, the presented study explores the ecology of ten species of native New Zealand broom, Carmichaelia, and their vulnerability to competition and herbivory, with the aim of gaining a better understanding of the significance of introduced species as a threat to rare indigenous plants in New Zealand. In particular, the study focuses on the relationship between characteristics of the Carmichaelia species and their vulnerability, as well as on other factors influencing the significance of introduced species as a threat. To gain a better understanding of the ecology of the Carmichaelia species, their current habitats and associated plant communities were investigated using quantitative-descriptive methods in the field. The effect of competition with introduced plants was studied in two glasshouse experiments, differentiating above ground competition for light from below ground competition for nutrients and water. The experiments focussed on the early life-stage of seedling establishment of the Carmichaelia species. The impact of herbivory by introduced mammals was studied in four field-based exclosure trials, focussing on the effects on survival and reproductive activity of adult Carmichaelia plants. The results showed that the effects of competition and herbivory vary between the different species. Furthermore, they provided a set of species characteristics that can be used as indicators to predict the vulnerability of Carmichaelia to the impact of introduced species. These indicators provide a useful tool for threatened species management, as they allow the identification of the most vulnerable species as well as the most significant threat to each species. Furthermore, the indicators can be used to group species, combining those with similar vulnerability profiles, and therefore, likely similar management needs. However, the example of the Carmichaelia species also illustrated that the use of indicators for the vulnerability of threatened species is limited and needs to be combined with case-by-case studies to verify the actual significance of threats for each population of concern. The vulnerability profiles derived from species’ characteristics can be used to guide such site specific studies, ensuring they focus on the most relevant threat factors. This combination of the understanding of general patterns in the vulnerability of species with targeted species and site-specific studies will lead to increased efficiency in the conservation management of threatened plant species.

This thesis examines the influence of management on vegetation at selected locations in the natural park ?Straz nad Ohri?. The main objective is to determine the current botanical composition of the stands and compare it with the previously collected data. The work will also contain assess of the current management and a design of possible measures to protect nature. Botanical survey of selected sites was conducted during the 2012 period. There are protected species of plants at these locations that need special management for their maintenance or possibly reproduction.

Brackish water ecosystems such as mangroves are among the most biodiverse in the world. The mangroves located in the Gulf of California, Mexico are not an exception. This sea has been studied several times due to its biodiverse coastal ecosystems, one of these sites being “Marismas Nacionales” or National Marshes in the southeast area of the Gulf, which was the focus of the thesis. Local fishing communities have been present in the area since pre-Hispanic times and the area became recognized for their abundant oyster, shrimp, and finfish yields during the XX century. Overexploitation of fisheries in Mexico and national financial crisis opened the door to neoliberal policy and law reforms which affected directly and still affect the subsistence, economy and political power of the fishers in the area. Because of the neoliberal reforms, shrimp aquaculture became an important economic activity in and around the region of Marismas Nacionales by the end of the 1980s. By the 1990s international and national protection, instruments were implemented to revert the damages and pressures created by overexploited fishers, as well as by the new aquaculture practices introduced in the ecosystem, giving Marismas Nacionales the status of the biosphere reserve. The figure of biosphere reserve has reverted the damages in the ecosystem while preserving the communal land inside of it. Nevertheless, since the biosphere reserve does not cover the whole ecosystem, the political boundaries of the biosphere reserve have also been detrimental for the ecosystem and local fishers’ land tenure that remained outside of it, creating an inside/outside effect. The study was done considering the perspectives of the actors involved, mainly the fishers in the area through semi-structured interviews gathered using a snowball method, through second-hand sources collection and literature review. The analysis was done through the political ecology and political economy perspectives to examine the conflicts that were found. The neoliberal laws from the period between 1986 and 1992 have not stopped the depletion of fisheries in the Marismas Nacionales ecosystem. Additionally, with the combination of a lack of formal credit schemes leading to an exploitation by permit holders and middlemen; fishers, in particular, free fishers, in the Marismas Nacionales ecosystem have become vulnerable, as well as scapegoats for the shortcomings of the flawed policies. The most affected fishers inside Marismas Nacionales ecosystem where found outside the limits of the biosphere reserve, demonstrating the deficiencies of the biosphere reserve. Additionally, I claim that conservation instruments and areas around Mexico could potentially become part of a process of primitive accumulation which could end up in privatizing those areas as seen in other places around the world. Moreover, shrimp aquaculture seems to benefit from the conservation policies. Further research is advised in regulatory processes and conservation law schemes, as well as an accurate implementation in the Marismas Nacionales wetlands, that considers all those implicated.

Despite an IUCN conservation status of critically endangered, Juliana’s golden mole (Neamblysomus julianae) has received no ecological research attention to date. The species urgently requires conservation attention, but a poor understanding its biology, ecology and distribution makes effective conservation planning almost impossible. In light of this, a thorough understanding of the habitat requirements for this habitat specific species was needed. Additionally, the cryptic lifestyle of Juliana’s golden mole has resulted in very few distribution records for the species. Little was known about the animals’ daily and seasonal activity patterns or movement patterns. This study revealed that Juliana’s golden mole is range restricted on account of sandy soils that have a uniform particle size distribution. This feature limits substrate compaction, making tunnelling far easier for these small mammals. In comparison to uninhabited areas, occupied habitat had greater vegetation cover provided by trees and shrubs, and this would be expected to provide a cooler and moister microenvironment. The ecological parameters associated with the species presence were then used, in addition to existing GIS data, to predict regions of potentially suitable habitat. This process revealed large potentially inhabitable areas in the northern parts of South Africa. Preliminary ground-truthing has shown the model to be relatively accurate with three potentially new populations having been identified. Contrary to what has been reported in the literature, Juliana’s golden mole does not appear to be strictly nocturnal. Instead, an adaptive pattern of activity was observed, governed by soil temperature. Body temperature was found to fluctuate to some degree with that of the soil temperature, but fluctuations were regulated by behavioural thermoregulation. Seasonal activity is highly correlated with rainfall. Rain moistens the soil making it significantly softer and far easier to tunnel through. Using this and other information acquired through the course of the study, the thesis culminates with an evaluation of conservation concerns and proposed conservation management actions. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Zoology and Entomology / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (M Inst Agrar (Sustainable Ecological Development))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

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The Hermit butterfly Chazara briseis is a species from the family Nymphalidae, inhabiting mostly short-stemmed dry steppes. In Central Europe, it is critically endangered. It is therefore currently the subject of many conservation activities, including reintroductions. In such translocations of individuals, it is important that the native and source populations be as closely related as possible in all respects. Therefore, individuals of two forms of this species, Ch. briseis pannonica (Austrian population) and Ch. briseis bataia (Czech population) were bred and their reproductive characteristics were recorded and the differences between the two forms were observed. During two seasons 5 Austrian and 8 Czech females were successfully bred. The Austrian and Czech populations differed mainly in the timing of adult hatching and the beginning of the laying of eggs by females - Austrian individuals are phenologically shifted to one week to 14 days earlier. Individual populations of the same species may also differ from each other in the presence of Wolbachia pipientis. This bacterium can affect the sex ratio in a population as well as the reproduction behavior of individuals. There was a suspicion of its presence in the Czech population. Therefore, a part of the Czech population was treated with...