Orientador: Ricardo Ribeiro Rodrigues / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T03:26:35Z (GMT). No. of bitstreams: 1 Jakovac_AnaCatarinaConte_M.pdf: 1934505 bytes, checksum: d87dbd9dcdf21233352a17e09fd573b4 (MD5) Previous issue date: 2007 / Resumo: A partir dos anos 90, a conscientização da sociedade e o aumento do atendimento à legislação ambiental fizeram proliferar muitas iniciativas de recuperação de áreas degradadas. A transposição do topsoil, rica fonte de sementes nativas e de matéria orgânica, deve ser uma técnica alternativa promissora. O topsoil já vem sendo utilizado com sucesso, mas sua aplicação ainda está restrita a áreas planas. A disponibilidade de topsoil associada à necessidade de recuperação de taludes com espécies nativas, inspirou a presente pesquisa. O objetivo foi avaliar a possibilidade de uso da técnica de transposição de topsoil para a recuperação de taludes de corte e aterro, identificando os fatores atuantes na sucessão secundária inicial da comunidade de plantas e suas implicações para a recuperação. Em um talude com inclinação de 30º foi depositada a camada de topsoil proveniente de uma área de floresta recém desmatada. Foram utilizadas quatro técnicas de contenção do topsoil depositado: madeiramento formando terraços (M), sulcos horizontais (S) e cada uma, M e S, associadas a linhas de adubação verde semeada (MAV e SAV). O delineamento experimental foi o de blocos ao acaso, em que cada tratamento possui três réplicas de 12x15 m2, distribuídas em três blocos. A densidade de indivíduos regenerantes e a riqueza de formas de vida foram monitoradas por 14 meses, e a porcentagem de solo exposto foi avaliada no último mês. Após os 14 meses foram registradas 150 espécies de todas as formas de vida. Os tratamentos apresentaram densidades cinco vezes maiores que o testemunho, variando de 5,2 a 22,6 indiv/m2, mas não foram diferentes entre si. O tratamento de sulcos (S) apresentou a maior porcentagem de solo exposto (Capítulo 1). Mais do que os tratamentos as características do topsoil e a densidade do banco de sementes do topsoil, diferentes entre os blocos experimentais, determinaram padrões distintos de colonização, de estrutura e de velocidade de recuperação das comunidades (Capítulo 2). Se observada a área experimental como um todo, formou-se uma comunidade heterogênea florística e estruturalmente, o que deve ser interessante para áreas em regeneração. Os resultados indicaram que a recuperação de taludes pode ser eficiente utilizando a técnica de transposição de topsoil desde que sejam utilizadas técnicas de contenção conjuntamente. Com a metodologia proposta, ampliam-se as possibilidades de uso do topsoil e possibilita-se a recuperação de taludes de corte e aterro com espécies nativas / Abstract: After the nineties, the awareness of the society and enhancement of legal environmental requirements resulted in a greater number of initiatives on degraded lands rehabilitation. The use of topsoil, which contains the forest seed bank and high concentrations of organic matter, has been successfully used, but its application still restrict to flat or low-declivity areas. The local availability of topsoil together with the necessity to rehabilitate slopes with native species community inspired this experimental research. The purpose of this study was to evaluate the topsoil transposition technique to rehabilitate slopes, aiming to identify the main factors acting over the initial succession of these communities and its implications for the rehabilitation process. At an embankment slope with 30° declivity we spread the topsoil collected in a surrounding area just after forest clear cut. Four contention techniques were tested: wood fences forming terraces, horizontal rips, wood fences with green manure and horizontal rips with green manure. The experiment was designed in casualized blocks were each treatment has three 12 x 15m2 replicas, distributed in three blocks. We monitored the regenerating community for 14 months, measuring the individual¿s density and the life forms richness. The percentage of exposed soil was measured on the last sampling. Afther 14 months, we registered 150 species including all life forms. In all treatments, the density of individuals was at least five times higher than in the control, ranging from 5,2 to 22,6 ind/m2. The density of individuals was not different among the four treatments, but the rips treatment showed the highest percentage of exposed soil (Chapter 1). The allochtonous soil characteristics, diferent among the experimental blocks, were the main determinants of the structure and floristic composition of regenerating communities. Differences of topsoil soil fertility and seed bank density determined different initial colonization patterns, as well as the community final structure and recovery speed (Chapter 2). Analyzing the whole experimental area, the growth of distinct communities at the same rehabilitated area resulted in a community with heterogeneous structure and floristic composition, which may be interesting for regenerating areas. The results showed that, together with contention techniques, the topsoil use as a source of propagules and organic matter can be efficient on slopes¿ rehabilitation. The proposed method expands the possibilities of topsoil use, allowing the rehabilitation of slopes and embankments with native species / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal

This thesis provides a description of the periglacial environment and features in the vicinity of Tiffindell Ski resort, on the slopes of Ben MacDhui (3001.2m.), the highest point of the East Cape Drakensberg, South Africa. Active and inactive periglacial features were located, mapped and described. Of particular interest were periglaciar slope deposits including gelifluction turf-banked lobes and stone lobes, and cryoturbation features including polygons and thufur. Local environmental factors, such as aspect, moisture, topography, soil texture and depth of freezing, appear to act as important controls on the spatial distribution of the periglacial features. Identification and quantification of periglacial processes in the regolith was investigated using temperature and soil moisture sensors coupled to dataloggers. Research was undertaken over a 16 month period from June 1995 to September 1996 so that comparisons between the winter conditions of 1995 and 1996 could be drawn. The Tiffindell area was observed to be characterised in the winter months by 'diurnal freezethaw days', as well as by 'ice days', 1996 experiencing colder temperatures than 1995. With more than 78% of the days from May to September 1996 being 'ice days', and simultaneously experiencing high soil moisture contents, freezing penetration to a depth of greater than 0.2m was observed to occur in the Tiffindell area, causing frost heave and gelifluction. The summer thaw of ice lenses that developed in the cold winter months caused surface movement downslope of gelifluction lobes of up to 39mm over an 18 month period, although movement declined rapidly with depth and was essentially restricted to the uppermost 130mm of the regolith. Other features such as sorted and non-sorted polygons and thufur were identified and found to be active under the present climatic conditions and depth of frost penetration at Tiffindell. Stone lobes were identified on the south and southeast-facing slopes at Tiffindell, but are apparently inactive under present climatic conditions. Their existence suggests the presence of severe seasonal frost in the past. The implications of the air and ground surface temperatures, and of seasonal frost penetration for the development of Tiffindell Ski resort were considered, and suggestions regarding their economic significance are presented.

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