Submitted by MARIANA CORREA DAIREL (maridairel@gmail.com) on 2018-05-29T13:32:19Z No. of bitstreams: 1 Dissertação_MarianaDairel.pdf: 2176755 bytes, checksum: 15173e4411a9c0edf054f8425b0128b8 (MD5) / Rejected by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br), reason: Prezada Mariana, O documento enviado para a coleção Instituto de Biociências Rio Claro foi recusado pelo(s) seguinte(s) motivo(s): - Falta a folha de aprovação, que deve ser solicitada à Seção de Pós-Graduação e deve ser inserida após a ficha catalográfica. - Falta o Abstract (geral) e as palavras chaves em inglês, que devem vir após o Resumo em português. Em caso de dúvidas entre em contato pelo email repositoriounesp@reitoria.unesp.br. Agradecemos a compreensão e aguardamos o envio do novo arquivo. Atenciosamente, Biblioteca Campus Rio Claro Repositório Institucional UNESP https://repositorio.unesp.br on 2018-05-29T14:15:32Z (GMT) / Submitted by MARIANA CORREA DAIREL (maridairel@gmail.com) on 2018-05-29T14:58:54Z No. of bitstreams: 1 Dissertação_MarianaDairel_2018.pdf: 3026271 bytes, checksum: 1b8e54d60ef03c2c75e6584b82e1ad04 (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-05-29T15:23:22Z (GMT) No. of bitstreams: 1 dairel_mc_me_rcla.pdf: 2894726 bytes, checksum: a451a6d4fa2118d57b4a79457d9f2c49 (MD5) / Made available in DSpace on 2018-05-29T15:23:22Z (GMT). No. of bitstreams: 1 dairel_mc_me_rcla.pdf: 2894726 bytes, checksum: a451a6d4fa2118d57b4a79457d9f2c49 (MD5) Previous issue date: 2018-04-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Espécies invasoras são aquelas capazes de se estabelecer em áreas além de sua ocorrência natural, ultrapassando barreiras geográficas e constituindo novas populações viáveis. A introdução de gramíneas africanas no Cerrado, como Melinis minutiflora P. Beauv e Urochloa brizantha (Stapf) R.D. Webster, pode levar a uma baixa heterogeneidade do sistema, deixando-o mais suscetível a distúrbios ambientais, alterando o equilíbrio da comunidade e os serviços ecossistêmicos. Em sistemas frequentemente perturbados, clareiras são criadas na paisagem e novas espécies são recrutadas para colonizar o espaço aberto, processo esse regido pelo nicho da regeneração. Espera-se que estes nichos se sobressaiam nas espécies invasoras em relação às espécies nativas, conferindo-lhes vantagens adaptativas na colonização desses espaços. Dessa maneira, o objetivo do estudo foi avaliar a dinâmica do banco de sementes de gramíneas em áreas com e sem invasão biológica, além de avaliar diferentes fatores que influenciam a germinação de gramíneas nativas. A área de estudo está inserida na Estação Ecológica de Itirapina, onde até 1998 havia uma plantação de Pinus caribaea, a qual foi removida e desde então a área está sob regeneração natural, sem interferência, com alto grau de invasão por gramíneas africanas. No primeiro capítulo, as amostras de solo foram coletadas nas parcelas experimentais controle do projeto da Profa. Dra. Alessandra Fidelis (FAPESP 2015/06743-0), delineado então parcelas com três tratamentos: dominada por uma das duas espécies invasoras, Melinis minutiflora e Urochloa brizantha, e parcelas com domínio de vegetação nativa (4parcelas/tratamento= 12 unidades amostrais). No segundo capítulo, as sementes de gramíneas nativas foram coletadas na Estação Ecológica de Itirapina e na Reserva Natural Serra do Tombador, triadas em laboratório e submetidas a tratamentos de flutuação de temperatura, simulando a oscilação de temperatura diária sobre a superfície do solo, e choques de temperatura simulando a passagem do fogo. O conhecimento mais detalhado sobre o banco de sementes em áreas invadidas é fundamental para elaboração de práticas de controle e manejo dessas espécies. Além disso, a germinação e viabilidade das sementes de gramíneas nativas são fatores importantes tanto para elucidar a regeneração natural via semente, compreendendo processos ecológicos relacionados à quebra da dormência fisiológica, quanto para aplicação de métodos físicos de restauração do Cerrado, como a semeadura direta. / Invasive species are those capable of establishing themselves in areas beyond its natural occurrence, surpassing geographical barriers and constituting new populations. The introduction of African grasses in Cerrado, Melinis minutiflora P. Beauv and Urochloa brizantha (Stapf) R.D. Webster, may low heterogeneity of the system, making it more susceptible to altering the balance of the community and ecosystems. In frequently disturbed systems, clearings are created in the landscape and new species are recruited to colonize the open space, which is governed by the regeneration niche. These niches are expected to be better in invasive species in relation to native species, giving them adaptive advantages in the colonization of these spaces. In this way, the objective of the study was to evaluate the dynamics of grasslands in areas with and without biological invasion, in addition to evaluating different factors that influence the germination of native grasses. The study area is located in the Estação Ecológica de Itirapina, where until 1998 there was a plantation of Pinus caribaea, which has been removed and since then the area is under natural regeneration, without interference, with a high invasion of Urochloa brizantha and Melinis minutiflora. In the first chapter, the soil samples were collected in the control plots of the project of Profa. Dr. Alessandra Fidelis (FAPESP 2015 / 06743-0), outlined then plots with three treatments: dominated by one of the two invasive species, Urochloa brizantha and Melinis minutiflora, and plots with dominance of native vegetation (4plots / treatment = 12 sample units). In the second chapter, grass seeds were collected at Estação Ecológica de Itirapina and in Reserva Natural Serra do Tombador, triads in the laboratory and submitted to treatments of temperature fluctuation, simulating the daily temperature oscillation on the soil surface, and heat shock simulating the passage of fire. More detailed knowledge about the soil seed bank in invaded areas is fundamental for the elaboration of practices of control and management of these species. In addition, the germination and viability of native grass seeds are important factors both to elucidate the natural regeneration through seed, comprising ecological processes related to break physiological dormancy of seed, and for application of physical methods of restoration of Cerrado, such as direct sowing.

Soil seed banks are a reservoir of viable seeds present in the soil in plant communities. They have been studied and characterized in various ways in different habitats. However, these studies are limited to modern seed banks. This study extends seed bank studies to the Paleozoic Era. It was hypothesized that size distribution and seed density in Paleozoic seed banks exhibit similar patterns as in modern seed banks. Seed sizes and seed density of fossil seed from Wise Virginia were estimated. Modern seed bank information was obtained from published data. Data were analyzed using one-way ANOVA and Kruskal-Wallis test. The Paleozoic size distribution was predominated by larger seeds and the estimated seed density of 19 200 seeds m-3 falls within the range of modern seed banks but at a higher end of modern seed bank densities. During the Paleozoic they were sufficient to insure regeneration of these economically important forests.

The objectives of this research were to investigate the ecological importance of soil seed reserves and seed rain on regeneration of a good condition sagebrush- grass range vegetation after a wildfire and draw conclusions leading to better understanding and management of such ecosystems. Investigations were conducted for two successive years on a community where major plants were neither rhizomatous nor sprouting. In such cases soil seed reserves and seed rain have to be the main source of regeneration. In addition to monitoring soil seed reserves and seed rain, vegetation changes during the past two years and the historical conditions of the study area were examined. Study of germinable soil seed reserve dynamics showed that fire can have a destructive effect on this portion of the community. Cheatgrass soil seed reserves were high even in good condition sagebrush-grass vegetation. Although fire reduced the Bromus tectorum seed bank by half, the cover of this grass increased to almost twice the level observed on the control (unburned) plots a year later. This shows the enormous reproductive capacity of this highly competitive weed species following a wildfire. Even though the pre-burn vegetation contained a high proportion of native perennial plants, soil seed reserves and seed rain had very small proportions of their germinable seeds. Timing of the fire is likely important in controlling undesirable range plants and their seeds. Had the fire occurred earlier when more seeds were attached to the culms, greater reduction in cheatgrass probably would have been obtained. Timing of the fire was just right to control sagebrush, because it occurred before their seed set and complete destruction of this species was achieved. Mormon tea was the only shrub to reestablish its cover relatively rapidly. This was related to its strong ability to sprout from root crowns. Greater germinable soil seed reserves were found under shrub canopies than in the inter spaces. This is probably related to the semi-logarithmic dispersal of seed where seed fall is greatest closest to mother plants (Harper 1977). Since flammable fuel follows the same pattern, it was found that fire has a serious impact on soil seed reserves at "hot" points, but temperatures were apparently not hot enough to cause much damage on seed banks at "cold" points in the former interspaces. Since soil seed reserves accumulate in significantly higher proportions in the surface 0-2 cm, fire has a more serious impact on the seeds in surface soil than those lower lower down. Variance of the germinable seed rain was so high that none of the grand totals, life forms totals and species values were statistically significant at alpha

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 5 uppsatser.

Thesis (M.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 72-79). Also available in electronic format on the Internet.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. "July 31, 1998." Document formatted into pages; contains viii, 108 p. : ill. (some col.), map. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 45-51). Also available on the World Wide Web.

Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: p. 241-260.