Research Doctorate - Doctor of Philosophy (PhD) / The records of environmental change in Australia’s arid zone can be greatly enriched by employing a multi-proxy approach and landscape-scale analysis. This research uses these tools to construct a palaeoenvironmental history of the Paroo/Warrego Region. While the Region’s flow regimes and water balances are characterised by medium-term (decadal) variability (Young, 1999), its hydrological records are inadequately brief. Subsequently, land and water management decisions are based on short term data, risking irreversible damage, desertification or loss of diversity. A better understanding of this highly dynamic landscape can thus improve the land and resource management outcomes. While dating was constrained by a lack of funds, the Paroo/Warrego history reconstructed from fluvial and aeolian deposits correlated well with events recorded from other inland regions of the Australian continent. In summary, this new research provided evidence of high lake water levels prior to the Last Glacial. The extreme aridity at the onset of Last Glacial caused long term drying of the lakes and mobilisation of the red sand dunes. In latter stages of the glacial phase the aridity gave way to periodic fluctuations between flood and drought events that probably lasted until 16 000 - 14 000 BP. The new climatic regime resulted in formation of gypsum lunettes and later, following reduction in gypsum supply, clay lunettes. The orientation of red sand dunes and lunettes indicates a more northerly extent of the westerlies than in modern times. Around the late Pleistocene-early Holocene boundary the climate became more stable and wetter, but still somewhat drier than during the pre-Last Glacial lacustrine phase. As a result, the region’s lakes reverted to a permanent and semi-permanent status. A strong aridity signal, comparable to the semi-regular droughts of the Last Glacial, was recorded in the Paroo/Warrego lakes during the late 1890s-1940s period of below average rainfall. It was followed by 50 years of wetter conditions with two extremely wet phases in the 1950s and the 1970s. Finally, the most recent records suggest a new drying trend. The semi-arid vegetation appears to have adapted to climate variability, with herbs and grasses expanding with the onset of wet conditions before being replaced by Chenopodiaceae as the landscape started to dry. The fresher lake basins and water courses were likely to provide refuge during prolonged arid phases and dispersal foci during intervening wetter periods, thus enabling greater flexibility in response to changes and enhancing resilience. The European land use interfered with the natural cycles and balances, leading to decrease in ground cover, suppression of fire, increase in runoff and catchment erosion, acceleration of sediment accumulation rates in wetlands, resulting in decline of their water holding capacity, and expansion of woody vegetation. The research improved the processing protocols, reference databases, and transfer of methods to enable greater sample processing efficiency and improve results. The use of multiple proxies (including biotic and abiotic components) and sites, as well as different depositional features, provided access to a broader picture of environmental change than was previously possible. It also facilitated multi-scale resolution, allowing discrimination between localised responses of individual lakes and regional trends. The full value of this research will come from informing natural resource managers, whose actions will shape the future landscapes of the Paroo and Warrego Region.

Research Doctorate - Doctor of Philosophy (PhD) / The records of environmental change in Australia’s arid zone can be greatly enriched by employing a multi-proxy approach and landscape-scale analysis. This research uses these tools to construct a palaeoenvironmental history of the Paroo/Warrego Region. While the Region’s flow regimes and water balances are characterised by medium-term (decadal) variability (Young, 1999), its hydrological records are inadequately brief. Subsequently, land and water management decisions are based on short term data, risking irreversible damage, desertification or loss of diversity. A better understanding of this highly dynamic landscape can thus improve the land and resource management outcomes. While dating was constrained by a lack of funds, the Paroo/Warrego history reconstructed from fluvial and aeolian deposits correlated well with events recorded from other inland regions of the Australian continent. In summary, this new research provided evidence of high lake water levels prior to the Last Glacial. The extreme aridity at the onset of Last Glacial caused long term drying of the lakes and mobilisation of the red sand dunes. In latter stages of the glacial phase the aridity gave way to periodic fluctuations between flood and drought events that probably lasted until 16 000 - 14 000 BP. The new climatic regime resulted in formation of gypsum lunettes and later, following reduction in gypsum supply, clay lunettes. The orientation of red sand dunes and lunettes indicates a more northerly extent of the westerlies than in modern times. Around the late Pleistocene-early Holocene boundary the climate became more stable and wetter, but still somewhat drier than during the pre-Last Glacial lacustrine phase. As a result, the region’s lakes reverted to a permanent and semi-permanent status. A strong aridity signal, comparable to the semi-regular droughts of the Last Glacial, was recorded in the Paroo/Warrego lakes during the late 1890s-1940s period of below average rainfall. It was followed by 50 years of wetter conditions with two extremely wet phases in the 1950s and the 1970s. Finally, the most recent records suggest a new drying trend. The semi-arid vegetation appears to have adapted to climate variability, with herbs and grasses expanding with the onset of wet conditions before being replaced by Chenopodiaceae as the landscape started to dry. The fresher lake basins and water courses were likely to provide refuge during prolonged arid phases and dispersal foci during intervening wetter periods, thus enabling greater flexibility in response to changes and enhancing resilience. The European land use interfered with the natural cycles and balances, leading to decrease in ground cover, suppression of fire, increase in runoff and catchment erosion, acceleration of sediment accumulation rates in wetlands, resulting in decline of their water holding capacity, and expansion of woody vegetation. The research improved the processing protocols, reference databases, and transfer of methods to enable greater sample processing efficiency and improve results. The use of multiple proxies (including biotic and abiotic components) and sites, as well as different depositional features, provided access to a broader picture of environmental change than was previously possible. It also facilitated multi-scale resolution, allowing discrimination between localised responses of individual lakes and regional trends. The full value of this research will come from informing natural resource managers, whose actions will shape the future landscapes of the Paroo and Warrego Region.

This research aims to analyze the environmental potentialities present in the effectiveness of area of organic agriculture in Sergipe Central Arid zone. It appears that the spreading of organic agriculture in Sergipe is taking place thanks to the construction of new social and environmental coexistence level values associated with the changes in management practices. The area of this analysis are the municipalities of Areia Branca, Itabaiana and Malhador, which are part of the territory of Central Sergipe Arid zone. To develop this research the study methodology was structured in three stages: Cabinet, which covers literature research, visiting the agencies and entities for secondary data collection and mapping survey; field step comprises study area observation and recognition, location points marking, semi-structured interviews application and the photographic survey; the last step is called synthesis, since the achieved results in the two previous steps will be analyzed wether the initial study hypothesis is proven or not. This geographical area methodological theoretical model of evaluation is related to the definition / evaluation of potentialities environmental indicators. Thus, the construction of these as instruments of potentialities environmental indicators matrix allowed a simplified and qualitative reading of environmental, social, economic and cultural needs of the study area, showing the organic system new territoriality configuration. Therefore, the analysis concluded that the surveyed municipalities have potentialities features that favor the development of organic farming, however, they also have limitations that contribute to slower growth of organic production in the study area. Thus, the potentialities are environmental sphere related, such as the use of natural resources and the practice of environmental conservation, and also the influence of historical tradition in the production and marketing of foodstuffs in the Arid zone. As for the limitations, they are related to difficulties in the social, economic and political spheres that hinder the full development of organic production. / Esta pesquisa objetiva analisar as potencialidades ambientais presentes na área de efetivação da agricultura orgânica no Agreste Central Sergipano. Verifica-se que a disseminação da agricultura orgânica em Sergipe está ocorrendo a partir da construção de novos valores de convivência social e ambiental associados às mudanças das práticas de manejo. O recorte espacial desta análise são os municípios de Areia Branca, Itabaiana e Malhador, que fazem parte do território do Agreste Central Sergipano. Para desenvolver esta pesquisa a metodologia de estudo foi estruturada em três etapas: gabinete, abrange pesquisa bibliográfica, visita a órgãos e entidades para coleta de dados secundários e levantamento cartográfico; a etapa campo compreende a observação e reconhecimento da área de estudo, a marcação de pontos de localização, a aplicação de entrevistas semi-estruturadas e o levantamento fotográfico; a última etapa foi denominada de síntese, uma vez que serão analisados os resultados alcançados nas duas etapas anteriores, comprovada ou não a hipótese inicial deste estudo. O modelo teórico metodológico de avaliação deste espaço geográfico está relacionado com a definição/avaliação de indicadores de potencialidade ambiental. Assim, o uso destes como instrumentos construtivos da matriz de indicadores de potencialidade ambiental permitiu uma leitura simplificada e qualitativa das necessidades ambientais, sociais, econômicas e culturais da área de estudo, evidenciando a configuração de novas territorialidades do sistema orgânico de produção. Logo, a análise concluiu que os municípios pesquisados apresentam características potenciais que favorecem o desenvolvimento do cultivo orgânico, contudo, também apresentam limitações que contribuem para a desaceleração do crescimento da produção orgânica na área de estudo. Assim, as potencialidades relacionam-se à esfera ambiental, a exemplo do uso dos recursos naturais e à prática de conservação ambiental, e, também, à influência da tradição histórica na produção e comercialização de gêneros alimentícios no Agreste. Já as limitações estão relacionadas às dificuldades encontradas nas esferas social, econômica e política que dificultam o pleno desenvolvimento da produção orgânica.

Research into seed biology and restoration ecology of areas disturbed by mining is crucial to their revegetation. Shark Bay Salt, a solar salt facility in the Shark Bay World Heritage Area in Western Australia has several areas of disturbance as a result of 'soil borrowing'. Soil from these areas termed 'borrow pits' was used to create infrastructure such as the roads and embankments surrounding the evaporation ponds. Many of the pits contain little to no vegetation after >10 years since disturbance ceased, hence research into their restoration is now essential. A vegetation survey at the site established the key species in the undisturbed vegetation, and investigated the vegetation in borrow pits subject to natural migration and topsoil replacement. The vegetation communities in the borrow pits were vastly different to those in the undisturbed vegetation, highlighting the need for research into revegetation. An investigation into the use of 'borrowed' topsoil on a small scale showed that seedling recruitment from 'borrowed' topsoil was generally similar in the donor site (natural vegetation) and the borrow pits. Due to the absence of topsoil for further revegetation, it was necessary to understand seed germination and dormancy characteristics to establish seed pre-treatments prior to seed broadcasting and seedling (greenstock) planting. An investigation into seed germination and dormancy characteristics of 18 common species revealed that most species germinated equally well at 26/13oC and 33/18oC, however seven species had improved performance at 26/13oC. Untreated seeds of seven species exhibited high germination. Seeds of two species had low imbibition, which increased with hot-water treatment, and hence require scarification for germination. Germination of seeds of three species substantially increased with gibberellic acid (GA3), smoke water (SW) and karrikinolide (KAR1, a butenolide isolated from smoke). Seeds of the remaining six species had low germination regardless of treatment. As a result, species were classified as likely to be non-dormant (44%), physiologically dormant (44%) or physically dormant (11%). Physiological dormancy of three species was at least partly alleviated by dry afterripening, whereby moisture content of seeds was adjusted to 13% or 50% equilibrium relative humidity and seeds were stored at 30oC or 45oC for several months. All iv after-ripening conditions increased germination percentage and rate of two species with one only germinating when treated with GA3 or KAR1. The germination of the third species was dependent on after-ripening temperature and seed moisture content.

La question de l’accès à l’eau potable se pose avec acuité pour les pays de la régionsubsaharienne où un individu sur trois n’a pas accès à une source d’eau améliorée.L’objectif de cette thèse vise à définir les conditions d’une gestion durable de l'eau pourla ville de Djibouti. Dans ce contexte, la question de l'approvisionnement en eau estenvisagée dans une perspective patrimoniale afin de tenir compte des particularités dela ressource en zone aride et des usages spécifiques qui lui sont associés dans unenvironnement marqué par la pauvreté. Un apport majeur de la thèse réside d'une partdans l’analyse du contenu d’une politique durable de l'eau à Djibouti en présenced’inadéquation entre l’offre et la demande de l’eau et, d'autre part, des implications decette politique en termes de tarification de la ressource selon les usages mais aussi enterme de répartition plus équitable de l'eau au sein de la population. La première partiede la thèse s’intéresse à l’étude de la disponibilité de cette ressource rare à travers sonmode de gestion ainsi qu’à sa mesure à l’aide d’indicateurs. Elle propose également uncadre d’analyse de la ressource en resituant les principaux concepts utiles à ladéfinition d’une gestion durable de l’eau. La seconde partie met l’accent sur l’analysedes déterminants de la demande en eau et des choix en matière d’approvisionnementpour Djibouti-ville. Pour ce faire, elle s’appuie sur une étude économétrique réalisée àpartir d’enquêtes auprès d’un échantillon de 400 ménages. L’estimation d’un modèleprobit multivarié permet de considérer que le choix d’être raccordé à un branchement àdomicile dépend des caractéristiques socio-économiques du ménage. Cette thèseapporte des résultats originaux sur l’accès à l’eau des ménages et montre en particulierle rôle joué par des facteurs tels que le revenu, la taille de la famille ou le niveaud’éducation du chef de famille dans les choix opérés par les ménages. / The issue of access to drinking water is one which is of paramount importance for thecountries of the sub-Saharan region where one individual out of three does not haveaccess to a water source. The aim of this thesis is to determine the conditions ofsustainable water management for the city of Djibouti. In this context, the issue ofwater supply is considered from an asset perspective in order to take into considerationthe peculiarities of this resource in a dry zone and its uses in particular in anenvironment marked by poverty. The main contribution of this thesis lies not only inthe analysis of the content of a sustainable water policy in Djibouti at a time when isthere is discrepancy between supply and demand, but also with an examination of theimplications of such a policy in terms of the pricing of this resource based on both itslevel of use and on a more even distribution within the population. The first part of thisthesis deals with an analysis of the access to this scarce resource according to how it ismanaged and measured with the help of indicators. A framework is then developedwith the help of some main concepts that are useful for defining a sustainablemanagement of water. The second part emphasizes the study of the determinants ofdemands in water and the choices in terms of the supply for Djibouti-city by using aneconometric study based on investigations into a sample of 400 households. Theassessment of multivariate probit model allows taking into account the connection of ahousehold to the service depends on its socio-economic markers. This thesis generatenew findings about household access to water supply and highlights the extent towhich such factor as income, the household size or the level of education of the head ofthe family influence the choices made by the household.