Made available in DSpace on 2014-06-11T19:26:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-09-09Bitstream added on 2014-06-13T20:33:46Z : No. of bitstreams: 1 ferreira_prs_me_jabo.pdf: 537782 bytes, checksum: 37e95c11aa1cbd5db672a924c5ccd3fb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O Projeto de Reintrodução do Cervo-do-pantanal de Porto Primavera foi implementado pelos pesquisadores do Núcleo de Pesquisa e Conservação de Cervídeos (NUPECCE) da Universidade Estadual Paulista, na Estação Ecológica de Jataí (E.E.J.), a fim de conservar a espécie no estado de São Paulo. Para que o sucesso de um programa de reintrodução seja atingido, vários fatores devem ser levados em consideração, entre eles possíveis problemas genéticos decorrentes do pequeno número de indivíduos fundadores, como a perda da diversidade genética devido à deriva genética e a perda do vigor devido à endogamia. Assim, a partir de 6 locos microssatélites nós estimamos os níveis de variabilidade genética dessa população e, juntamente com dados de campo foi possível reconstruir a genealogia da mesma. Foram analisados no total 42 indivíduos: 8 fundadores, 14 nascidos no local e 20 indivíduos da população original. O número total de alelos encontrados na população original foi de 30, perfazendo uma média de 5 alelos por loco, com locos variando de 4 a 7 alelos. Já, na população reintroduzida, o número total de alelos encontrados foi 21, com média de 3,5 alelos por loco, e locos variando de 1 a 4 alelos. A grande perda alélica observada aqui indica que a população reintroduzida passou por um forte gargalo genético em decorrência do efeito fundador sofrido durante sua formação. Em contrapartida, a partir da geração fundadora até a segunda geração da E.E.J., a perda de alelos foi visivelmente menor, apenas 4 alelos foram perdidos. Em acréscimo, dados de heterozigosidade mostram que a população esta mantendo os níveis de diversidade genética (geração fundadora H=0,5; segunda geração H=0,625). A endogamia é um mecanismo inevitável... / The Reintroduced Project of marsh deer was implemented by the researchers from the Deer Research and Conservation Center (NUPECCE) of Unesp, in Jataí´s Ecological Station (E.E.J.), to understand the process of colonization of small marshes patches that remain in the São Paulo state. In order to make a reintroduction project successful, several factors must be taken into account; among those, possible genetic problems arising from the small number of founding individuals, such as the loss of genetic diversity due to genetic drift and the loss of fitness due to inbreeding. Hence, from 6 microsatellite loci, we estimated the genetic variability levels of this population and, together with the field data, we were able to reconstruct the genealogy of the members. We analyzed 42 individuals: 8 founders, 14 individuals born into the reintroduced population and 20 individuals from the source population. The total number of alleles found in the original population was 30 (5 alleles per locus), with loci ranging from 4 to 7 alleles. In the reintroduced population, the total number of alleles found was 21 (3.5 alleles per locus) and loci ranging from 1 to 4 alleles. The major allelic loss observed indicates that the reintroduced population went through a strong genetic bottleneck resulting from the founding effect suffered during its establishment. On the other hand, in the generations of the reintroduced population of the E.E.J., the loss of alleles was noticeably smaller. Furthermore, heterozygosity data show that the population has been maintaining the levels of genetic diversity (Founder generation H=0.5; second generation H=0.625). Inbreeding is an inevitable mechanism in small populations; however, the indexes that... (Complete abstract click electronic access below)

The impact of the Deepwater Horizon blowout on coastal wetlands can be understood through investigating carbon loading and microbial activity in salt marsh sediments. Carbon influx causes pore water sulfide to increase in wetland sediment, making it toxic and inhospitable to marsh vegetation. High sulfide levels due to increased microbial activity can lead to plant browning and mortality. Preliminary analyses at Marsh Point, Mississippi indicated that sulfate reducing bacteria are more active in contaminated marsh, producing sulfide concentrations 100x higher than in noncontaminated marsh. Sediment electrode profiles, hydrocarbon contamination, and microbial community profiles were measured at three additional locations to capture the spatial sedimentary geochemical processes impacting salt marsh dieback. Findings indicate that response to contamination is variable due to physical and biogeochemical processes specific to each marsh. Temporal evaluation indicates that there is a lag in maximum response to contamination due to seasonal effects on microbial activity.

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In this study we investigated the effect of tidal forcing on iron cycling in intertidal saltmarsh sediments (ISS). Historically, sulfate has been considered the major terminal electron acceptor involved in organic carbon remineralization in ISS. Although sulfate is a more efficient electron acceptor for organic matter degradation in anoxic ISS, irons rapid recycling at the surface of ISS may allow it also to be an important electron acceptor for the remineralization of organic matter. Bioturbation, macrophyte-mediated irrigation, and semidiurnal tidal forcing in this environment may increase the abundance of O2 in the top few cm of the sediment, rapidly oxidizing iron and inhibiting sulfate reduction. To determine if the cycling of iron may be faster than previously thought in these sediments, we combined sediment core chemical profiles of reduced and oxidized insoluble iron with in-situ electrochemical profiles of O2, Fe2+, soluble organic-Fe3+ complexes, FeS(aq), and hydrogen sulfide in the top few centimeters of unvegetated creek bank sediments over several tidal cycles. We also installed monitoring wells in the tidal creek bank to quantify tidal forcing and to investigate tidal direction in the sediments. We built a transient, reactive transport model to simulate measured geochemical profiles and test our understanding of diagenetic processes. Additional tests were run on the model to investigate the importance of bioirrigation compared to tidally-induced porewater advection. Results indicate that tidal action is a more dominant transport process. It affects the cycling of iron in ISS by flushing reduced species out of the sediment during flood tide, and allowing oxygen and oxidized species deeper into the sediment during ebb tide. As a result, amorphous iron oxides are replenished at the sediment surface, and microbial iron reduction may be the main respiratory process in the first tens of centimeters of creek bank saltmarsh sediments subjected to intense tidal forcing.

Since 1970, U.S. Army Corps of Engineers, Galveston District, has been using dredged sediments from the Houston ship channel to create and restore salt marshes in Galveston Bay. Some projects have failed due to excessive sediment erosion or siltation. The research reported here applies an engineering approach to analysis of tidal creeks in natural and beneficial use marshes of Galveston Bay. The hydrodynamic numerical model, DYNLET, was used to assess circulation in marsh channels. A preliminary sediment transport model was developed to analyze erosion and deposition for the same channels. In situ flume experiments were conducted to determine the sediment erodibility in natural and constructed marshes. A natural reference marsh, Elm Grove, was studied to understand marsh hydrodynamics and model calibration. The model results show that DYNLET can largely duplicate the marsh hydrodynamics and the sediment transport model can provide preliminary indication of erosion in tidal creeks. Analysis of the preliminary channel layout of the beneficial-use marsh demonstrated that channels will have sufficient circulation and optimum velocities.

Thesis (M.S.)--Oregon State University, 1992. / Typescript (photocopy). Includes bibliographical references (leaves 105-112). Also available via the World Wide Web.

Thesis (M.A.)--San Francisco State University, 1979. / "December, 1979." Includes bibliographical references (leaves 149-153).

Thesis (M.S.)--University of Wisconsin -- La Crosse, 1975. / Includes vita. Digitized and made available by the University of Wisconsin--La Crosse, Murphy Library. Includes bibliographical references (leaves 74-78). Online version of print edition.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Ecology and Evolution." Includes bibliographical references (p. 127-138).

Thesis (Ph.D.)--University of Groningen, 2007. / Includes bibliographical references (leaves 106-116). Available also electronically on the Internet.