Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-03-03T17:10:47Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Helton Pablo Moura Santos.PDF: 1447223 bytes, checksum: 5676806a271a7d14c8375994a1782651 (MD5) / Made available in DSpace on 2016-03-03T17:10:47Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Helton Pablo Moura Santos.PDF: 1447223 bytes, checksum: 5676806a271a7d14c8375994a1782651 (MD5) Previous issue date: 2015-02-26 / Water scarcity is a reality in many parts of the world and the demand for water for irrigated agriculture is quite significant, so the use of lower quality water is a viable alternative for these purposes. The objective of the present study to investigate the effects caused by irrigation with two types of water and nitrogen fertilization on growth, development and production of upland cotton (Gossipium hirsutum L), BRS TOPÁZIO. The experiment was conduced in the field in the period from March 25, 2014 to August 15, 2014 at Estação Experimental de Tratamentos Biológicos de Esgotos - EXTRABES, neighborhood of Tambor, in Campina Grande city, Paraíba. The experimental design was completely randomized and factorial 2x4, with three repetitions, totaling 24 units, the factors made up of four nitrogen rates (0, 20, 40 and 60 kg. Ha-1) and two types of water (sewage sanitary treated in a UASBH reactor and artesian wellwater). In plants that received the treatment with treated sewage, given its nutrient richness, then the observed increase in stem diameter and height of the subjects, larger leaf area and higher yield, as compared with the irrigated with wellwater. The 40 kg. ha - ¹ nitrogen dose associated with treated sewage water had the highest production rate. / A escassez de água é uma realidade em diversas regiões do mundo e a demanda de água pela agricultura irrigada é bastante significativa, sendo assim, a utilização de água de qualidade inferior é uma alternativa viável para estes fins. Objetivou-se, com o presente estudo, investigar os efeitos causados pela irrigação com dois tipos de água e adubação nitrogenada, no crescimento, desenvolvimento e produção do algodão herbáceo (Gossipium hirsutum L), cultivar BRS TOPÁZIO. O experimento foi conduzido em campo no período de 25 de março de 2014 a 15 de agosto de 2014 na Estação Experimental de Tratamentos Biológicos de Esgotos - EXTRABES, bairro do Tambor, no município de Campina Grande, estado da Paraíba. O delineamento experimental foi inteiramente casualizado e com arranjo fatorial 2x4, com três repetições, totalizando 24 unidades, sendo os fatores constituídos de quatro doses de nitrogênio (0, 20, 40 e 60 kg. ha -1 ) e dois tipos de água (esgoto sanitário tratado em um reator UASBH e água de poço artesiano). Nas plantas que receberam o tratamento com esgoto sanitário tratado, dado a sua riqueza em nutrientes, observou-se então o aumento no diâmetro caulinar e altura dos indivíduos, maior área foliar e maior produção, quando comparadas com as irrigadas com água de poço. A dose de nitrogênio de 40 kg. ha -1 associada à água de esgoto sanitário tratado apresentou o maior índice de produção.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O presente trabalho tem por objetivo principal efetuar a caracterizaÃÃo e avaliaÃÃo do desempenho econÃmico dos sistemas de produÃÃo de ovinos da raÃa Morada Nova no Estado do CearÃ. Para tanto foram aplicados questionÃrios junto aos produtores de ovinos da raÃa Morada Nova no Estado do CearÃ. Para caracterizaÃÃo tÃcnica, dividiu-se o sistema de produÃÃo de ovinos em quatro componentes: gerenciamento do produtor, infra-estrutura do sistema de produÃÃo, manejo dos rebanhos e desempenho dos rebanhos. Em seguida, foram determinados os Ãndices tecnolÃgicos para cada componente, separadamente e para o conjunto deles, com base na respectiva tecnologia recomendada. Para a caracterizaÃÃo socioeconÃmica dos produtores, foram analisados sete fatores, a saber: infra-estrutura e produÃÃo de volumosos, rebanhos e manejo de produÃÃo, produÃÃo, aspectos ambientais, mÃo-de-obra, crÃdito rural e administraÃÃo do empreendimento. A anÃlise econÃmica foi feita utilizando-se a metodologia do Sistema Integrado de Custos AgropecuÃrios â CUSTAGRI. Foram identificados quatro nÃveis tecnolÃgicos de sistemas de produÃÃo que foram usados para a anÃlise dos aspectos socioeconÃmicos, estimativas de custos e avaliaÃÃo de rentabilidade. Os sistemas de produÃÃo de ovinos Morados Nova mais tecnificados mostraram-se lucrativos e capazes de viabilizar o desenvolvimento sustentÃvel no meio rural, proporcionando a fixaÃÃo do homem no campo com emprego e renda. As principais dificuldades observadas pelos produtores estÃo ligadas à mÃo-de-obra desqualificada, polÃticas de crÃdito insuficientes e falta de polÃticas pÃblicas focadas na atividade. / This chapter has the aim to make the technical analysis of production systems in Morada Nova sheep to complement the project "Characterization and basis for the genetic improvement of sheep Morada Nova", coordinated by Embrapa Goats and Sheep, with the financial support of Banco do Nordeste (FUNDECI / ETENE). In order to achieve this objective, primary research was conducted with data collected through the application of questionnaires to the sheep farmers of the municip ality of Morada Nova, Cearà State. To assess the technological level, the system of sheep was divided into four components: the producer management, infrastructure, production system, herd management and performance of the herds. Next, we determined the te chnological indices for each component separately and for all of them, based on its recommended technology. We found four production systems baptized by the technology index for each producer, being called "high technology gap" - level D, "regular technolog ical gap" - level C, "low technology gap" - level B and "high art " - level A. It was found that 17% of farmers fall in the level A, 33% at level B, Level C in 33% and 17% at level D.

FundaÃÃo de Amparo a Pesquisa do Estado do Piauà / O Nordeste do Brasil onde predomina o clima semiÃrido se caracteriza por ambientes de exploraÃÃo intensiva dos recursos naturais como a exploraÃÃo agrÃcola por pequenos produtores na forma de subsistÃncia. AÃÃes antropogÃnicas tÃm provocado limitaÃÃes na exploraÃÃo dos recursos naturais com consequentes perdas de solo e Ãgua e comprometimento da sustentabilidade ambiental das bacias hidrogrÃficas. Neste sentido, à fundamental a compreensÃo dos processos hidrossedimentolÃgicos, biolÃgicos e bioquÃmicos na definiÃÃo de estratÃgias para o melhor gerenciamento de pequenas bacias hidrogrÃficas e na definiÃÃo de planos de sustentabilidade dos agroecossistemas. Assim, teve-se como hipÃteses: (1) ecossistemas naturais do semiÃrido apresentam poucas perdas de sedimentos e nutrientes em decorrÃncia das chuvas, e tais sedimentos tÃm alta atividade microbiolÃgica em relaÃÃo aos solos de agroecossistemas tradicionais; (2) o estabelecimento de relaÃÃes entre variÃveis sedimentolÃgicas, microbiolÃgicas e bioquÃmicas à essencial para o entendimento e adoÃÃo de tÃcnicas de manejo sustentÃvel em agroecossistemas do semiÃrido; (3) a composiÃÃo mineralÃgica e os atributos fÃsicos dos sedimentos de arraste sÃo determinados pela erosividade das chuvas sobre os solos dos agroecossistemas. Para testar tais previsÃes objetivou-se: (a) quantificar a produÃÃo e caracterizar quÃmica, fÃsica e mineralogicamente os sedimentos de arraste de diferentes agroecossistemas do semiÃrido; (b) avaliar alteraÃÃes da atividade microbiolÃgica, da biomassa microbiana e da atividade enzimÃtica e quantificar a populaÃÃo de fungos micorrÃzicos arbusculares de sedimentos de arraste de diferentes agroecossistemas; (c) avaliar a granulometria dos sedimentos de arraste levando em consideraÃÃo a erosividade das precipitaÃÃes pluviomÃtricas; (d) relacionar a qualidade dos solos e dos sedimentos de arraste com os processos de degradaÃÃo, visando subsidiar o manejo mais sustentÃvel de agroecossistemas. Foram considerados os agroecossistemas de quatro microbacias hidrogrÃficas: (1) vegetaÃÃo de mata raleada (MR), com a manutenÃÃo de espÃcies vegetais com diÃmetro basal ≥ que 10 cm, e espÃcies de crescimento herbÃceo; (2) vegetaÃÃo nativa (MN), representando as condiÃÃes naturais de pequenas bacias rurais do semiÃrido brasileiro; (3) agrossistema com capim Andropogon gayanus Kunt (PAST); (4) agroecossistema com prÃtica usual da agricultura de subsistÃncia (AGRS). As microbacias estavam instrumetadas com pluviÃmetro tipo âVille de Parisâ, calha Parshall, coletores de sedimentos tipo armadilha (bed load), e pluviÃgrafo automÃtico. Os resultados obtidos permitem concluir: (1) a maior erodibilidade dos Vertissolos (das Ãreas de mata e pastagem) em relaÃÃo ao Luvissolo do sistema de agricultura de subsistÃncia promove maior produÃÃo de sedimentos de arraste, independentemente da vegetaÃÃo tÃpica do semiÃrido e dos sistemas tradicionais, e do nÃmero de eventos que geraram escoamento superficial; (2) a biomassa, a atividade microbiana e a perda de esporos de fungos micorrÃzicos arbusculares em sedimentos de arraste apresenta sensibilidade Ãs mudanÃas de uso da terra; (3) as fraÃÃes de quartzo e feldspato permite identificar neste mineral maior diversidade nos sistemas com Vertissolos (MN, MR e PAST) em relaÃÃo ao Luvissolo de AGRS, enquanto a identificaÃÃo de esmectitas e vermiculita em argilas tratadas de sedimentos das matas (MR e MN) e pastagem (PAST) caracteriza a drenagem deficiente daqueles em relaÃÃo a este sistema, cuja argila tratada revelou presenÃa de caulinita com picos mais elevados; (4) o Ca++ e K+ em quantidade nos sedimentos de arraste constitue uma importante reserva mineral para sua exploraÃÃo; (5) nÃo se verifica uma relaÃÃo direta entre a erosividade das chuvas (EI30) e a produÃÃo de areia e argila em sedimentos de arraste nos agroecossistemas de mata (MR e MN) e tradicionais (PAST e AGRS); (6) os agroecossistemas de mata (MR e MN) apresentam maiores teores de agregados estÃveis (AE) em relaÃÃo aos sistemas tradicionais (PAST e AGRS), favorecendo a qualidade biolÃgica dos solos; (7) tÃcnicas de manejo sÃo de grande importÃncia para o desenvolvimento de estratÃgias para a gestÃo de bacias hidrogrÃficas e na definiÃÃo de planos de sustentabilidade na regiÃo semiÃrida. / The Northeast of Brazil wich predominantes semiarid climate is characterized by intensive exploitation of natural resources and the environment for small farm producers in the form of subsistence. Anthropogenic activities have caused limitations in the exploitation of natural resources with consequent losses of soil and water and environmental sustainability commitment watershed. In this sense, it is fundamental to understanding the hydrosedimentological, biological and biochemical definition of strategies for better management of small watersheds and defines plans for sustainability of the agroecosystems. Thus, it was taken as hypotheses: (1) natural vegetation systems have small losses of sediment and nutrients due to rain, and the sediments have high microbial activity in relation to soils traditional agroecosystems; (2) the establishment of relationships between sedimentological, microbiological and biochemical variables is essential for the understanding and adoption of sustainable management techniques in semiarid agroecosystems; (3) the mineral composition and physical properties of the sediments produced by drag are determined by rainfall erosivity on soils of agroecosystems. To test these predictions the objectives were: (a) quantify the production and characterization of chemical, physical and mineralogical sediments by drag of differents semiarid agroecosystems; (b) evaluate changes in microbial activity, microbial biomass and enzyme activities and quantify the population of mycorrhizal fungi in sediment of differents agroecosystems; (c) evaluate the size of the sediments by drag considering the erosivity of rainfall; (d) relate the quality of soils and sediments by drag with degradation processes, to support sustainable management of agroecosystems. Systems the four watersheds were considered: (1) vegetation thinned forest (MR), with the maintenance of plant species with basal diameter ≥ 10 cm, and species of herbaceous growth; (2) native vegetation (MN), representing the natural conditions of small rural basins of the Brazilian semiarid; (3) agroecosystem with pasture Andropogon gayanus Kunt (PAST); (4) agroecosystem with usual practice subsistence agriculture (AGRS). The watersheds were instrumented with rain gauge type "Ville de Paris", gutters type Parshal, sediments collectors (bed load), and automatic meters. The results show: (1) the higher erodibility of Vertisols (forested areas and grassland) compared to Luvisol of subsistence agriculture promotes greater sediment produced by drag, regardless of typical vegetation of semiarid systems and traditional system and the number of events that promoted surface runoff ; (2) the biomass, microbial activity and the loss of spores of mycorrhizal fungi in sediments produced by drag shows sensitivity to changes in land use; (3) the fractions of quartz and feldspar mineral allows identifying this greater diversity in systems with Vertisols (MN, MR and PAST) in relation to Luvissol in the, while identification of vermiculite and smectite clays in sediments of treated samples of MR, MN and PAST characterizes those deficit drainage in relation to this system, which treated clay showed the presence of kaolinite with higher peaks; (4) the Ca+ + and K+ on sediment produced by drag constitutes an important reserve for mineral exploitation; (5) are not note a direct relationship between rainfall erosivity (EI30) and the production of sand and clay sediments produced by drag in agroecosystems (MR and MN) and traditional (PAST and AGRS); (6) the forest agroecosystems (MR and MN) have higher levels of stable aggregates (AE) compared to traditional systems (PAST and AGRS), favoring the biological quality of the soil; (7) management techniques are of great importance for the development of strategies for watershed management plans and the definition of sustainability in the semiarid region.

Os micro-organismos apresentam uma imensa diversidade genética e desempenham funções únicas e cruciais na manutenção de ecossistemas. Uma dessas funções é a produção de enzimas extracelulares, que ajudam na degradação da matéria orgânica e são cada vez mais procuradas e exploradas pela indústria. Essa propriedade aumenta a busca por enzimas que possam ser utilizadas nos diversos setores industriais com maior aproveitamento e baixo custo. A celulase pertence a essa classe de enzimas e é formada por um complexo multienzimático capaz de hidrolisar celulose por meio da quebra da ligação β,1-4. A partir dessa característica da celulase, foi realizada uma expressão heteróloga relacionada com a hidrólise da celulose em biblioteca metagenômica de solo da Caatinga. Foram realizados testes de produção enzimática por meio dos quais selecionamos os clones 283/A8 e 307/E11 como melhores produtores de endoglicanases. Com o objetivo de analisar a cinética de produção de celulases pelos clones, estes foram inoculados em diferentes fontes de celulose, pH e temperatura. A faixa ideal de pH foi 5,0 e de temperatura, 50º C, verificada para as enzimas Celulase Total, Endoglicanase e β-glicosidase. Quanto à termoestabilidade, as enzimas presentes mantiveram mais de 60% da atividade inicial após 2 horas de incubação a 50º C. O perfil de proteínas analisado por SDS-PAGE demonstrou que os clones secretam um conjunto de enzimas celulolíticas com 25 a 100 KDa, quando cultivado em farelo de trigo, e 30 a 60 KDa, quando cultivados em CMC. No ensaio de cromatografia para o clone 307/E11, foram selecionadas 5 frações que obtiveram melhores resultados na dosagem enzimática e testados frente ao pH e à temperatura. O resultado obtido foi que o complexo enzimático bruto, extraído do sobrenadante produzido pelo clone, possui melhor atividade frente ao pH e à temperatura do que as frações parcialmente purificadas. / Microorganisms are distinguished by a wide genetic diversity and they perform unique and crucial functions concerning the maintenance of ecosystems. One of those functions is the production of extracellular enzymes, which help in the degradation of organic matter and which are increasingly wanted and explored by industry. Such feature boosts the search of enzymes that can be exploited in several industrial sectors with improved full use and low cost. Cellulase belongs to such class of enzymes and it is composed of a multi-enzymatic complex which is able to hydrolyse cellulose through the breaking of the chemical bond β,1-4. Considering such attribute of the cellulase, a heterologous expression, related to cellulose hydrolysis in a metagenomic inventory of the soil of Caatinga, was realized. Tests of enzymatic production were performed, and through them, we could elect the clones 283/A8 and 307/E11 as the best endoglicanase producers. Those clones were inoculated in different cellulose sources, pH and temperature, so that we could analyse the kinetic of cellulase production between them. The ideal pH range was 5.0 and the ideal temperature range was 50º C (122º F), verified for the enzymes Total Cellulase, Endoglicanase and β-glucosidase. With regard to thermostability, the present enzymes kept more than 60% of the initial activity after 2 hours of incubation at 50º C (122º F). The proteins profile analysed with the help of SDS-PAGE proved that the clones secrete a group of cellulolytic enzymes with a weight average of 25 to 100 KDa, when cultivated in wheat bran, and of 30 to 60 KDa, when cultivated in CMC. Five fractions with the best results, regarding enzymatic dosage and tested before pH and temperature, were chosen by the chromatography research for the clone 307/E11. The achieved result proved that the raw enzymatic complex, extracted from the supernatant produced by the clone, develops a better activity before pH and temperature than the fractions partially purified.

Submitted by Natalie Mendes (nataliermendes@gmail.com) on 2015-07-28T23:45:37Z No. of bitstreams: 1 Disserta??o Lara Raisa Cheles.pdf: 1045712 bytes, checksum: feec175794486c72d1aa9c07b185ee70 (MD5) / Made available in DSpace on 2015-07-28T23:45:37Z (GMT). No. of bitstreams: 1 Disserta??o Lara Raisa Cheles.pdf: 1045712 bytes, checksum: feec175794486c72d1aa9c07b185ee70 (MD5) Previous issue date: 2014-05-06 / Item withdrawn by Luis Ricardo Andrade da Silva (lrasilva@uefs.br) on 2015-08-01T01:02:00Z Item was in collections: Cole??o UEFS (ID: 1) No. of bitstreams: 1 Disserta??o Lara Raisa Cheles.pdf: 1045712 bytes, checksum: feec175794486c72d1aa9c07b185ee70 (MD5) / Item reinstated by Luis Ricardo Andrade da Silva (lrasilva@uefs.br) on 2018-06-08T21:00:08Z Item was in collections: Cole??o UEFS (ID: 1) No. of bitstreams: 1 Disserta??o Lara Raisa Cheles.pdf: 1045712 bytes, checksum: feec175794486c72d1aa9c07b185ee70 (MD5) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The use of plant extracts and phytochemicals with medicinal purpose is one of the oldest forms of medical applications of humanity, and currently, the use of herbal medicines has increased in population. Considering the popular use of Lippia origanoides in the treatment of respiratory and gastrointestinal diseases and antiseptic action of its essential oil, this study aimed to test, through of the Minimum Inhibitory Concentration and Minimum Microbicidal Concentration, the antimicrobial activity of the essential oils of L. origanoides resulting from plants after treatment with plant metabolism regulators: acetylsalicylic acid, jasmonic acid, 6-benzylaminopurine, gibberellic acid, Stimulate ? and distilled water (control), continuing earlier work by our group. The results for the antimicrobial activity of the studied species varied according to the treatment received, collection period and the microorganism tested. In general, the 12 essential oils tested showed activity against the seven test microorganisms used. Oils resulting from treatment with acetylsalicylic acid, jasmonic acid and gibberellic acid had significantly lower MIC values, highlighting their high efficacy; being evident that the time for collecting the samples interfered in these results. The oil resulting from the first collection of plants were in general more efficient than the third. There was significant difference between the MIC values for strains of C. albicans CCMB 266 and CCMB 286, the latter being more sensitive to the oils from both collection periods. / O uso de extratos vegetais e fitoqu?micos com finalidade medicinal ? uma das mais antigas formas de aplica??o medicinal da humanidade, e atualmente, a utiliza??o de medicamentos fitoter?picos tem aumentado na popula??o brasileira. Considerando a utiliza??o popular de Lippia origanoides no tratamento de doen?as respirat?rias e gastrointestinais e a a??o antiss?ptica de seu ?leo essencial, o presente trabalho teve como objetivo testar, por meio do Concentra??o Inibit?ria M?nima e Concentra??o Microbicida M?nima, a atividade antimicrobiana, dos ?leos essenciais de L. origanoides resultantes de plantas ap?s tratamentos com os reguladores do metabolismo vegetal: ?cido acetilsalic?lico, ?cido jasm?nico, 6-benzilaminopurina, ?cido giber?lico, Stimulate? e ?gua destilada (controle), dando continuidade a um trabalho anterior de nosso grupo. Os resultados relativos ao potencial antimicrobiano da esp?cie estudada variaram de acordo com o tratamento recebido, per?odo de coleta e o micro-organismo testados. Em geral, os 12 ?leos essenciais testados apresentaram atividade contra os sete micro-organismos teste utilizados. Os ?leos resultantes do tratamento com ?cido acetilsalic?lico, ?cido jasm?nico e ?cido giber?lico apresentaram valores de MIC consideravelmente baixos, evidenciando a alta efic?cia dos mesmos, sendo evidente que a ?poca de coleta das amostras interferiu nestes resultados. Os ?leos resultantes da primeira coleta de plantas foram, em geral, mais eficientes que os da terceira. Houve diferen?a significativa entre os valores de MIC para as cepas de C. albicans CCMB 266 e CCMB 286, sendo a ?ltima mais sens?vel aos ?leos de ambos os per?odos de coleta.

A Articulação no Semiárido (ASA Brasil) organização que reúne mais de 3000 movimentos sociais, sindicatos, ONGs, associações, coletivos locais e regionais surge, em 1999, com o intuito de fortalecer a reivindicação por soluções definitivas às dificuldades de abastecimento e acesso à água no semiárido brasileiro. Por um lado, o enfoque da ASA está no desenvolvimento e consolidação de um amplo leque de estratégias organizativas voltadas à valorização da autonomia e ao fortalecimento político dos camponeses. Por outro lado, as organizações e movimentos que compõem a ASA dedicam-se à construção e difusão de tecnologias alternativas, de baixo custo, que possibilitam o armazenamento hídrico descentralizado por meio da captação de água da chuva, sendo as cisternas de placas a principal entre elas. Através das estratégias assumidas e das tecnologias alternativas desenvolvidas, as organizações e movimentos sociais ligados à ASA assumem uma posição política contrária às tradicionais soluções hídricas assentadas nas grandes obras de açudagem e nas medidas paliativas de combate à seca, sobretudo por estas resultarem na concentração do abastecimento de água e abrirem espaço para a reprodução de relações de dominação político-clientelistas, sendo a troca de água por voto sua expressão mais evidente. Em 2003, foi criado o Programa de Formação e Mobilização Social para a Convivência com o Semiárido: Um Milhão de Cisternas Rurais (P1MC), fruto de uma parceria estabelecida entre a ASA e o governo federal. Transformada em política pública, a distribuição das cisternas de placas exigiu da ASA a configuração de um aprimorado processo organizativo, de modo a possibilitar um considerável alargamento do alcance espacial dessa articulação e sua atuação em múltiplas escalas geográficas. Tomando como referência a estrutura organizativa e as estratégias configuradas pela Articulação, dedicamo-nos, nesta tese, à análise da dimensão política das ações de convivência com o semiárido desenvolvidas pela ASA. Nesta abordagem, constituem-se objeto de nosso interesse as implicações decorrentes da relação estabelecida com o Estado e os antagonismos frente às tradicionais políticas de combate à seca. Com base nas informações obtidas através de entrevistas, análise documental e trabalhos de campo, fomos levados a considerar as ações político-interventivas e as representações que acompanham as perspectivas de combate à seca e convivência com o semiárido como ideologias geográficas que evidenciam, através do regionalismo, contrapostos interesses de classe, revelando um conflito que encontra na relação entre política e espaço um elemento central. / The Articulation in the Semi-arid (ASA Brazil) organization that assembles more than 3.000 social movements, syndicates, Non-governmental Organizations, associations, regional and local collectivities arose in 1999, with the intention for strengthen the demand for definite solutions to supplies and water access difficulties of the Brazilian semi-arid. On the one hand, ASAs focus is development and consolidation of wide range organized strategies directed in valuation of autonomy and political strengthening of the peasants. On the other hand, ASAs organizations and movements pursue for building and propagation cheaper alternative technologies that allow decentralized water storage through rain capture, being plates tanks the main option among them. Through the adopted strategies and developed alternative technologies, organizations and social movements joined ASA admit an opposite political position to traditional water troubleshooting based on big buildings and palliative ways to struggle against drought, mainly for these ones result in water storage concentration and open up space for reproduction of political-customer domination relationships, being water change for vote the most evident expression of this. In 2003, The Formation and Social Mobilization for Living in the Semi-Arid Program: One Million of Rural Tanks (P1MC) created as a product of an established union between ASA and federal government. It has been become a public policy, the plates tanks distribution required from ASA the configuration of a refined organizational process, so that to enable a reasonable expansion of spatial reach of this articulation and its action on multiple geographic scales. Taking organizational structure and configured strategies by ASA as references, here, we aimed to analyze political dimensions of relationship with the semi-arids actions developed by ASA. In this approach, the object is composed of consequential implications from established interaction between the State and opponents against traditional politics of struggle against drought. Based on obtained data by interviews, documentary analysis and field works, we have considered that political-interventional actions and representations which are side by side to the struggle against drought and relationship with the semi-arid perspectives as geographic ideologies, that shows through the regionalism, contrary class interests, revealing a disagreement essentially triggered by relation between politics and space.

Northeastern Brazil is hydrologically characterized by recurrent droughts leading to a highly vulnerable natural water resource system. The region contains the Caatinga biome, a sparsely studied ecosystem, covering an area of approximately 800,000 km2. Reduced wateravailability is projected to take place in large regions of the globe, including Northeastern Brazil. Given the strong interactions between climate and vegetation, research has addressed climate change effects on natural and agricultural ecosystems. In this context, soil hydraulic properties are essential to assess soil water flow, and thus the ability of soil to supply water to plants at potential rates under different ranges of pressure head. Based on that, the aims of this thesis are: to increase insight in water balance components for the Caatinga biome, under current and future climate scenarios; and to assess the ability of soils in supplying water to plants by the further development of an existing matric flux potential approach, followed by its application to a group of soils from two Brazilian climatic zones (semi-arid and subhumid). Both for current and future climate scenarios, hydrological simulations were performed with SWAP model parameterized for a preserved Caatinga basin of 12 km2. The validation of the simulations was performed using a dataset of daily soil-water content measurements taken at 0.2 m depth in the period from 2004 to 2012. The soil water supplying capacity was evaluated through a multilayer matric flux potential approach, coupling the soil hydraulic properties, root length density and plant transpiration. Regarding the current climate conditions, the Caatinga biome returns 75% of the annual precipitation to the atmosphere, whereas the partitioning of total evapotranspiration into its components (transpiration, evaporation and interception) on annual basis accounts for 41%, 40% and 19%, respectively. Evapotranspiration and air temperature are most sensitive to soil moisture during the periods June-September and December-January. Concerning the future climate, transpiration was enhanced by 36%, soil evaporation and interception losses reduced by 16% and 34%, respectively. The amount of precipitation returned to the atmosphere was on average 98%. For both climate scenarios, the soil-plant-atmosphere fluxes seem to be controlled by the surface soil layer (0-0.2 m) which provides, on average, 80% of the total transpiration, suggesting that the Caatinga biome may become completely soil-water pulse dominated under scenarios of reduced water availability. The matric flux potential analysis revealed that soils from the semiarid zone were able to deliver water to plants at potential rates under a wider range of bulk soil pressure head (-36 to -148 m), whereas the soils from the wetter zone showed more hydraulic restriction with limiting soil water potential above -1.5 m. For the analyzed soils, only a negligible increase in available water results from decreasing the root water potential below -150 m, therefore, in order to adapt to water-limited conditions, plant species may invest in other adaptive strategies, rather than spending energy in structures that allow a reduction of the lower suction limit in their tissues. / O Nordeste do Brasil é hidrologicamente caracterizado por secas recorrentes, tornando os recursos hídricos naturais altamente vulneráveis. Nesta região está o bioma Caatinga, ocupando uma área de aproximadamente 800.000 km2. Cenários de déficit hídrico são projetados para grandes regiões do globo, incluindo o Nordeste brasileiro. Devido às interações entre clima e vegetação, várias pesquisas têm abordado os efeitos das mudanças climáticas sobre os ecossistemas naturais e agrícolas. Neste contexto, as propriedades hidráulicas do solo são essenciais para avaliar o movimento de água, e assim a capacidade de fornecimento de água às plantas. Com base nesta contextualização, os objetivos desta tese são: simular os componentes do balanço hídrico do bioma Caatinga para cenários climáticos atuais e futuros; e avaliar a capacidade de alguns solos em fornecer água às plantas a partir de uma abordagem de potencial de fluxo matricial. Para os cenários climáticos atuais e futuros, simulações hidrológicas foram realizadas com o modelo SWAP, parametrizado para uma microbacia de 12 km2, inserida em área de Caatinga preservada. A validação das simulações foi processada a partir de medidas diárias do conteúdo de água do solo na profundidade de 0,2 m no período de 2004 a 2012. A capacidade do solo em fornecer água às plantas foi avaliada através da atualização de uma função de potencial de fluxo matricial, que acopla as propriedades hidráulicas do solo, densidade de comprimento radicular e transpiração das plantas, aplicada a um grupo de solos da zona climática semiárida e sub-úmida. Como resultados principais destacam-se: nas condições climáticas atuais, o bioma Caatinga retorna 75% da precipitação anual para a atmosfera como evapotranspiração, particionada entre seus componentes (transpiração, evaporação e intercepção) em 41%, 40% e 19%, respectivamente. Evapotranspiração e temperatura do ar foram sensíveis à umidade do solo durante os períodos de junho-setembro e dezembro-janeiro. Em relação ao cenário climático futuro, a taxa de transpiração foi acrescida em 36%. A evaporação do solo e a interceptação foram reduzidas em 16% e 34%, respectivamente. A quantidade de precipitação devolvida para a atmosfera foi em média 98%. Para ambos os cenários climáticos, é sugerido que os fluxos de água no sistema solo-planta-atmosfera são controlados pela camada superior do solo (0-0,2 m), fornecendo, em média, 80% do total transpirado, indicando que, caso os cenários de disponibilidade hídrica reduzida se confirmem, o bioma Caatinga pode se tornar completamente dependente dos pulsos de água no solo. A partir do potencial de fluxo matricial limitante revelou-se que os solos da região semiárida são capazes de manter o fluxo de água às plantas em taxas potenciais em condições de solo seco (potencial matricial limitante variando de -36 a -148 m), enquanto que, os solos da região mais úmida indicaram severa restrição hidráulica, com potencial matricial limitante maior do que -1,5 m. Ainda para os solos analisados, a atribuição de potencial na superfície da raiz inferior a -150 m não ocasionou aumento de disponibilidade hídrica, indicando que valores menores que -150 m não implicam em uma estratégia viável para suportar baixa disponibilidade hídrica.

This study examines how people in dryland areas cope with food insecurity and adversities over time. It draws from the experience of the Gogo people living in Mvumi in the semiarid zone of central Tanzania, an area with a long history of food shortages. The study specifically examines the potential for dryland resources to sustain livelihoods. The study looks at the historical perspective of the problem in order to explore factors influencing the food situation in the area. It specifically investigates the role of local knowledge as a factor for adapting to dryland conditions by exploiting seasonality and local diversity. A detailed account is made of the coping strategies among three identified wealth groups in the area. Apart from their wealth levels, households in these wealth categories differ in how they mobilise and deal with labour in various seasons. Households in the well-off group have greater ability in mobilising and using external labour as well as accumulating and managing food surplus. The households in the intermediate group are flexible in utilising their own labour by performing various farm and non-farm activities according to their seasonalities. The households in the poor category sell their own labour and perform various farm and non-farm activities regardless of the season. It is clear from the study that different wealth groups differ in their ability to develop immediate coping into more pro-active livelihood strategies. The study winds up by assessing the potentials of the prominent land resource utilisation strategies in terms of economic, social and environmental perspectives.

Phytostabilization is an emerging technology for the remediation of mine tailings sites. In arid and semiarid environments, mine tailings disposal sites are a major source of environmental pollution as they are subject to eolian dispersion and water erosion. Mine tailings are acidic to neutral, high in metal content, and nutrient poor. Furthermore, these sites remain unvegetated even after decades of no additional mining activity. In arid and semiarid regions, climatic variables such as high winds, salinity, and drought exacerbate the problem. The Klondyke mine tailings site is a model site for studying plant establishment in mine tailings within semiarid regions. It was a lead and zinc ore- processing operation from 1948 to 1958 and is similar in physicochemical characteristics to other acidic pyritic mine tailings.In a greenhouse study, a native drought tolerant halophyte, Atriplex lentiformis (Torr.) S. Wats., was evaluated for its potential as a phytostabilization candidate in compost-amended tailings from the Klondyke site. Germination, plant growth, and metal uptake of A. lentiformis were examined, and the microbial community was monitored by enumeration of autotrophic iron- and sulfur-oxidizing bacteria as well as heterotrophic bacteria. Results demonstrated that with 10 to 15% compost addition, growth of A. lentiformis was not affected and shoot metal concentrations were generally not a concern for foraging animals. Furthermore, the heterotrophic bacterial community is severely stressed but recovers with compost addition and successful plant growth. Therefore, A. lentiformis is a good candidate for phytostabilization of mine tailings with compost amendments.Poor revegetation of mine tailings has been attributed to the microbial community involved in acidifying tailings; however, no thorough microbial studies have been conducted. The second study characterizes the bacterial community of the Klondyke site and compares it to an offsite control sample. Results demonstrate that the heterotrophic community is indicative of soil health as it has a positive relationship with pH, phylotype richness, and diversity. Also, the mine tailings contain an unexplored diversity of acidophiles that are important in maintaining acidity and thus, metal bioavailability. Therefore, the bacterial community in mine tailings should be monitored in phytostabilization studies to evaluate restoration.

This dissertation reports the results of a field based study examining sediment transport and bed mobility in a low-ordered, ephemeral watershed. Runoff and sediment transport concentrations were sampled at the watershed outlet to determine flow discharge and sediment flux during approximately 21 flow events, from 1998 - 2007. Sediment collected in flow was measured for grain-size distribution to determine if specific grain-size fractions behave differently while in transport. The coarse sediment yield was measured for mass and grain-size distribution at the watershed outlet for two years, 2005 - 2006. Further, the arrangement and composition of the channel bed material was comprehensively mapped using terrestrial-based photogrammetry for the years, 2005 - 2006. Results show that patterns of sediment transport are complex, controlled in part by flow hydraulics but also by other phenomena. Some of the variation in sediment transport is determined by grain-size. Grain-sizes with different sources within the watershed and that transported by different transport modes were observed to follow different patterns of transport. Also, the channel bed, which serves as the source for the coarse fraction of the sediment transport, was observed to change in grain composition during periods of flow. This tendency for the bed material to evolve in time likely affected the amount and composition of the sediment grains that were entrained from it.An additional objective of this dissertation was to determine how unique the observed patterns of sediment transport were to low-order ephemeral channels. Sediment transport and yield were modeled using bed load transport formulae designed to capture the physical mechanics of transport as observed in perennial streams. Results show that contemporary transport models predict transport within the field site with similar accuracy as that in many perennial systems but not well enough to rely on their predictions for many engineering applications.