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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Regime de distúrbio e dinâmica da regeneração natural na Floresta Pluvial Atlântica Submontana / Disturbance regime and natural regeneration dynamics in the Lower Montane Atlantic Rain Forest

Lima, Renato Augusto Ferreira de 19 April 2007 (has links)
Em uma parcela permanente de 10,24 ha na Floresta Pluvial Atlântica Submontana do Parque Estadual Carlos Botelho (Sete Barras, SP, Brasil), este estudo teve o intuito de descrever o regime de distúrbio do dossel e avaliar a regeneração natural sob diferentes regimes de luz. Para tanto, foi realizado o levantamento de todas as clareiras da parcela, que foram mensuradas e tiveram sua idade aproximada estimada. Em seguida, foram instaladas 42 parcelas de 10x10m para avaliar a regeneração natural em três regimes luminosos: dossel contínuo (18 parcelas), clareiras pequenas a médias (11) e clareiras grandes com abundância de Guadua tagoara (Nees) Kunth (13). O regime de luz foi caracterizado por fotografias hemisféricas tomadas ao centro das parcelas. O estudo da regeneração natural foi divido em: estrato herbáceo (i.e., ervas menores que um metro de altura), avaliado através da cobertura do solo estimada pelo método de interceptação de linha; e estrato arbustivo, avaliado através dos indivíduos com altura maior que 1m, e com diâmetro à altura do peito menor que 5cm. Para estes indivíduos anotou-se a espécie, diâmetro, altura total e área de copa, além da presença de partes reprodutivas e substrato de germinação. Informações sobre hábito, grupo sucessional e síndrome de dispersão das espécies também foram obtidas. Após um ano, uma reavaliação permitiu analisar a mortalidade, danos, recrutamento e crescimento. Apesar de 67% das clareiras terem sido menores que 150 m2 , o regime de distúrbio foi atípico, principalmente pela contribuição de clareiras maiores que 750 m2 , e pela área média e total que variaram respectivamente de 419 a 799 m2 , e de 26 a 49%, dependendo do método de delimitação de clareira. A densidade foi de 6 clareiras.ha -1 e a taxa de recorrência variou entre 91 e 220 anos, dependendo dos métodos. Houve diferença significativa entre os ambientes para a maioria dos índices de luz, especialmente para a radiação total incidente com médias entre 909 e 2.400 mols.m-2.ano-1. Observou-se diferença significativa entre ambientes na cobertura por ervas, porém os resultados variaram entre espécies. No estrato arbustivo, houve diferença significativa na composição e abundância das espécies, inclusive entre clareiras médias e sub-bosque. A densidade de ervas e arbustos foi maior nos ambientes mais iluminados, assim como a densidade de pioneiras e secundárias iniciais. O recrutamento em um ano (16%) apresentou diferenças nos ambientes, com 63% dos recrutas apenas nas grandes clareiras. O mesmo não ocorreu com a taxa de mortalidade cujas principais causas foram os danos físicos e dessecamento. Para os 13% de indivíduos danificados em um ano, houve destaque para danos ligados à extração de palmito. Apenas os danos físicos naturais apresentaram diferença entre ambientes, com grandes clareiras sendo as mais danosas. No geral e entre as 25 espécies avaliadas separadamente, houve uma tendência de crescimento maior com o aumento da incidência luminosa. Clareiras pequenas a médias tiveram significativamente maior riqueza, diversidade e menor dominância de espécies que o sub-bosque. Clareiras grandes com bambu tiveram menor riqueza e diversidade, mas contribuíram com a manutenção da diversidade beta da parcela permanente. / In a 10.24 ha permanent plot of Tropical Lower Montane Atlantic Rain Forest in the Carlos Botelho State Park (Sete Barras, SP, Brazil), this study aimed to describe the canopy disturbance regime and to assess natural regeneration under different light regimes. In order to do so, the plot was completely surveyed for canopy gaps that were measured and had their approximate age estimated. Then, 42 10x10 m plots were established to evaluate natural regeneration under three light regimes: understory (18 plots), small to medium canopy gaps (11 plots) and large gaps abundant in Guadua tagoara (Nees) Kunth (13 plots). The light regime was characterized through hemispherical photographs taken at each plot center. Natural regeneration was dived into: herb stratum (i.e., herbs below one meter in height) assessed through soil coverage using the line intercept method; and shrub stratum or all plant individuals taller than one meter high and thinner than 5 cm in diameter at breast height. All individuals were identified to species and measured for diameter, height, crown height and area, besides notes on the presence of reproductive structures and germination substrate. Information on growth form, dispersal syndrome and ecological group were also obtained for each species. After one year, one reevaluation was made to assess mortality, damages, recruitment and growth. Although 67% of gaps were smaller than 150 m2 , the plot disturbance regime was atypical mainly by the contribution of gaps bigger than 750 m2 and by the average and total gap area that varied respectively from 419 to 799 m2 , and from 26 to 49% depending on the gap delimitation method. Gap density was 6 gaps.ha-1 and the turnover rate varied from 91 to 220 years depending on the gap method employed. There was significant difference between environments among the light index, especially for total incident radiation with means varying from 909 and 2,400 mols.m-2.y-1. It was found significant differences on herb soil coverage between environments, although the results varied among species. In the shrub stratum, species composition and abundance was significantly different, even between small to medium canopy gaps and the understorey. Herb and shrub densities were bigger in the more enlightened environments, as well as pioneer and early secondary species densities. Recruitment over the year (16%) was different between environments with large gaps accounting for 63% of all recruits. Similar difference was not found for mortality rate that had physical damage and desiccation as main death causes. Amid the 13% of damage individuals in the course of one year, there was noticeable contribution of damages linked to illegal extraction of palm-heart. Differences between environments were present only for physical damages with large gaps being the most damaging environment. In general and among the 25 species evaluated separately, there was a tendency of bigger growth with enhancement in light incidence. Small to medium gaps had significantly higher species richness and diversity, and lower dominance compared to the understorey. Large gaps had lower richness and diversity, but they contributed to maintain beta diversity of the permanent plot.
72

Pedra do Sino: impacto sobre a biota e capacidade de carga tur?stica de uma trilha no Parque Nacional da Serra dos ?rg?os, RJ.

Schutte, Michel de Souza 29 June 2009 (has links)
Made available in DSpace on 2016-04-28T14:56:17Z (GMT). No. of bitstreams: 1 2009 - Michel de Souza Schutte.pdf: 2931677 bytes, checksum: ea9efef9ca48d88655f11a37b55a41bd (MD5) Previous issue date: 2009-06-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The disorderly growth of tourism directed at protected natural areas, with the fragmentation and destruction of the Atlantic Forest, brings to light a new concern with the use of public conservation units found in this biome. Accordingly, the National Park Serra dos ?rg?os, being close to major urban centers in Brazil and make great importance in natural attractions, it is subject to a significant increase in visitation and associated impacts. So, in this work were evaluated the impacts generated by the visitation of Pedra do Sino trail - most visited attraction in this park by mountaineers - to identify negative effects on the biotic and abiotic environment. Two different methods of suport capacity, that take into account the use of various indicators, were used. We selected the herbaceous vegetation, the seed bank and litter fauna of ants as biotic indicators, and physical aspects and behavior of visitors as abiotic indicators. Setting up four areas distant from the path (0, 10, 20 and 40m), a total of 12 plots in each area, there was the response of biota to the environment related to edge. The physical indicators were directly analyzed along the trail and visitors conduct through questionnaires based on Program to Natural Environments Conscious Conduct, at MMA, applied to visitors from Pedra do Sino. We found a significant effect on the herbaceous vegetation due to higher incidence of light in the edge, substantial effects weren t find on taxocenose of ants, and mainly on the seed bank, suggesting the use of the bank as an indicator of seedlings, as the mere presence of the seed does not ensure the success of developing them. The physical aspects indicated problems related to poor drainage, erosion, presence of shortcuts, waste, garbage, and others. The visitors, despite the high level of education, had low knowledge on techniques for minimum impact, and show little concern itself with the conditions of the trail, increase the number of visitors and strategies set by park management. Suport capacity found is close to the set, although other indicators should be added to obtain a final value more consistent with the reality of the area. The two methodologies (Capacidad de Carga Turistica - CCT and Visitor Impact Management - VIM) were shown to be complementary. The CCT becomes important to establish an exact number of visitors to the trail and VIM for greater emphasis on qualitative aspects. Two structures when used on the spectrum of a greater number of indicators, participation of various researchers and the audience are shown to shape the decisions taken by managers on the public use in conservation units in the Atlantic Forest. / O crescimento desordenado do turismo direcionado ?s ?reas naturais protegidas, associado ? fragmenta??o e destrui??o da Floresta Atl?ntica, traz ? luz uma nova preocupa??o com o uso p?blico das Unidades de Conserva??o encontradas neste bioma. Neste sentido, o Parque Nacional da Serra dos ?rg?os, por estar pr?ximo aos grandes centros urbanos brasileiros e por apresentar grande relev?ncia em atrativos naturais, torna-se alvo de um expressivo aumento da visita??o e seus impactos associados. Com isto, no presente trabalho, foram avaliados os impactos gerados pela visita??o a trilha da Pedra do Sino atrativo mais visitado por montanhistas neste Parque -, sobre o meio bi?tico e abi?tico. Para tanto, foram utilizadas duas diferentes metodologias de capacidade de carga que levam em considera??o a utiliza??o de diversos indicadores. Como indicadores biol?gicos foram selecionados a vegeta??o herb?cea, o banco de sementes e a fauna de formigas da serapilheira; al?m de medidas f?sicas e de conduta dos visitantes como indicadores abi?ticos. Para avaliar o efeito do pisoteio sobre a biota foram estabelecidas quatro dist?ncias da trilha (0, 10, 20 e 40 m), num total de 12 parcelas em cada ?rea. Os indicadores f?sicos foram, diretamente, analisados ao longo da trilha e a conduta dos visitantes atrav?s de question?rios baseados no programa de Conduta Consciente em Ambientes Naturais, do MMA, aplicados aos visitantes provenientes da Pedra do Sino. Foi encontrado efeito significativo sobre a vegeta??o herb?cea devido a maior incid?ncia luminosa no ambiente de borda, n?o sendo encontrados efeitos substanciais sobre a taxocenose de formigas e, principalmente, sobre o banco de sementes, sugerindo a utiliza??o do banco de pl?ntulas como indicador, j? que a simples presen?a das sementes n?o assegura o sucesso de desenvolvimento das mesmas. Os aspectos f?sicos demonstraram uma s?rie de problemas relacionados ? m? drenagem, eros?o, presen?a de atalhos, dejetos, lixo, dentre outros. Os visitantes, apesar do elevado n?vel de instru??o, apresentaram baixo conhecimento sobre as t?cnicas de m?nimo impacto, al?m de demonstrarem-se pouco preocupados com as condi??es da trilha, o aumento do n?mero de visitantes e as estrat?gias de manejo estabelecidas pelo Parque. A capacidade de carga encontrada aproxima-se da estabelecida, embora outros indicadores devam ser acrescidos para obten??o de um valor final mais condizente com a realidade da ?rea. As duas metodologias utilizadas (Capacidade de Carga Tur?stica - CCT e Manejo do Impacto dos Visitantes - VIM) mostraram-se complementares. A CCT torna-se importante por estabelecer um n?mero exato de visitantes para a trilha e o VIM por dar maior ?nfase aos aspectos qualitativos. Ambas as estruturas quando utilizadas sobre o espectro de um maior n?mero de indicadores, participa??o de diferentes pesquisadores e do p?blico alvo s?o indicadas para delinear as tomadas de decis?o pelos gestores sobre o Uso P?blico em Unidades de Conserva??o na Floresta Atl?ntica.
73

Monitoring Vegetation Change in the Kosciuszko Alpine Zone, Australia

Scherrer, Pascal, n/a January 2004 (has links)
This thesis examined vegetation change over the last 43 years in Australia's largest contiguous alpine area, the Kosciuszko alpine zone in south-eastern Australia. Using historical and current data about the state of the most common vegetation community, tall alpine herbfield, this thesis addressed the questions: (1) what were the patterns of change at the species/genera and life form levels during this time period; (2) what were the patterns of recovery, if recovery occurred, from anthropogenic disturbances such as livestock grazing or trampling by tourists; (3) what impacts did natural disturbances such as drought have on the vegetation and how does it compare to anthropogenic disturbances; and (4) What are the benefits, limitations and management considerations when using long-term data for assessing vegetation changes at the species/genera, life form and community levels? The Kosciuszko alpine zone has important economic, cultural and ecological values. It is of great scientific and biological importance, maintaining an assemblage of vegetation communities found nowhere else in the world. It is one of the few alpine regions in the world with deep loamy soils, and contains endemic flora and fauna and some of the few periglacial and glacial features in Australia. The area also forms the core of the Australian mainland's most important water catchment and is a popular tourist destination, offering a range of recreational opportunities. The vegetation of the Kosciuszko alpine zone is recovering from impacts of livestock grazing and is increasingly exposed to pressures from tourism and anthropogenic climate change. At the same time, natural disturbances such as drought and fire can influence the distribution, composition and diversity of plants. Thus, there is a need for detailed environmental data on this area in order to: (1) better understand ecological relationships; (2) understand existing and potential effects of recreational and management pressures on the region; (3) provide data against which future changes can be assessed; and (4) provide better information on many features of this area, including vegetation, for interpretation, education and management. The research in this thesis utilised three types of ecological information: (1) scientific long-term datasets; (2) photographic records; and (3) a comparison of disturbed and undisturbed vegetation. This research analysed data from one of the longest ongoing monitoring programs in the Australian Alps established by Alec Costin and Dane Wimbush in 1959. Permanent plots (6 transects and 30 photoquadrats) were established at two locations that differed in the time since grazing and have been repeatedly surveyed. Plots near Mt Kosciuszko had not been grazed for 15 years and had nearly complete vegetation cover in 1959, while plots near Mt Gungartan showed extensive impacts of grazing and associated activities which only ceased in 1958. Some transect data from 1959 to 1978 have been analysed by the original researchers. The research presented in this thesis extends this monitoring program with data from additional surveys in 1990, 1999 and 2002 and applies current methods of statistical evaluation, such as ordination techniques, to the whole data set for the first time. Results indicated that the recovery from livestock grazing and the effects of drought have been the main factors affecting vegetation. Recovery from livestock grazing at the three transects at Gungartan was slow and involved: (1) increasing genera diversity; (2) increasing vegetation cover; (3) decreasing amounts of bare ground; and (4) a directional change over time in species composition. Patterns of colonisation and species succession were also documented. In 2002, 44 years after the cessation of grazing, transects near Mt Gungartan had similar vegetation cover and genera diversity to the transects near Mt Kosciuszko, but cover by exposed rock remained higher. A drought in the 1960s resulted in a temporary increase of litter and a shift in the proportional cover of life forms, as grasses died and herb cover increased at both locations. Proportions of cover for life forms reverted to pre-drought levels within a few years. The results also highlighted the spatial variability of tall alpine herbfield. The photoquadrats were surveyed in the years 1959, 1964, 1968, 1978 and 2001 and are analysed for the first time in this thesis. After comparing a range of methods, visual assessment using a 130 point grid was found to be the most suitable technique to measure vegetation cover and genera diversity. At the 18 quadrats near Mt Gungartan, there was a pattern of increasing vegetation cover as bare areas were colonised by native cudweeds and the naturalized herb Acetosella vulgaris. Revegetation from within bare areas largely occurred by herb species, while graminoids and shrub species predominately colonised bare ground by lateral expansion from the edges, eventually replacing the colonising herbs. At the 12 quadrats near Mt Kosciuszko, vegetation cover was almost complete in all years surveyed except 1968, which was at the end of a six year drought. Similar to the results from the transect study, the drought caused an increase in litter at both locations as graminoid cover declined. Initially herb cover increased, potentially as a result of decreased competition from the graminoids and a nutrient spike from decaying litter, but as the drought became more severe, herb cover also declined. Graminoid cover rapidly recovered after the drought, reaching pre-drought levels by 1978, and was at similar levels in 2001. Herb cover continued to decline after peaking in 1964. The photoquadrat study also documented the longevity and growth rates of several species indicating that many taxa may persist for several decades. It further provided insights into replacement patterns amongst life forms. In addition to assessing vegetation change following livestock grazing and drought at the long-term plots, recovery from tourism impacts was examined by comparing vegetation and soils on a closed walking track, with that of adjacent undisturbed tall alpine herbfield at a series of 22 paired quadrats. Fifteen years after the track was closed there was limited success in restoration. Over a quarter of the closed track was still bare ground with non-native species the dominant vegetation. Plant species composition differed and vegetation height, soil nutrients and soil moisture were lower on the track which had a higher compaction level than adjacent natural vegetation. The results presented in this thesis highlight that tall alpine herbfield is characterised by nearly entire vegetation cover which is dominated by graminoids, followed by herbs and shrubs in the absence of disturbance by livestock grazing, trampling or drought. The studies also showed that under quot;average" conditions, the relative cover of herbs and graminoids remained fairly stable even though there can be considerable cycling between them. Spatial variability in terms of taxa composition was high. The only common introduced species in unrehabilitated sites was Acetosella vulgaris, which was effective at colonising bare ground but was eventually replaced by other native species. However, in areas actively rehabilitated, such as on the closed track, non-native species introduced during revegetation efforts still persist with high cover 15 years after their introduction. Monitoring of vegetation change is also important at the landscape scale. This thesis provides a review of the potential use, the limitations and the benefits of aerial photography to examine vegetation change in the Kosciuszko alpine zone. Numerous aerial photography runs have been flown over the area since the 1930s for government agencies, industry and the military. Some of these records have been used to map vegetation communities and eroding areas at a point in time. Other studies compared different types and scales of photographs, highlighting in particular the benefits and potential of large scale colour aerial photography to map alpine vegetation. However, despite their potential to assess vegetation change over time, a temporal comparison of vegetation in the Kosciuszko alpine zone from aerial photographs has not been completed to this date. Historical photographs may not be easy to locate or access and difficulties with vegetation classification may restrict the practicality of using historical aerial photographs to assess vegetation change. Despite these issues, aerial photography may provide a very useful and efficient tool to assess changes over time when applied appropriately, even in alpine environments. The development of digital classification techniques, the application of statistical measures of error to both methodology and data, and the application of geographic information systems are likely to further improve the practicality of historical aerial photographs for the detection of vegetation change and assist in overcoming some of the limitations. The results presented in this thesis highlight the need for limiting disturbance, for ongoing rehabilitation of disturbed areas and for long-term monitoring in the Kosciuszko alpine zone. The results contribute to our understanding of how vegetation may change in the future and may be affected by new land use activities and climate change. This type of information, which otherwise would require the establishment of long-term studies and years of monitoring, can assist land managers of this and other important protected areas. The study highlights how the use and expansion of already existing datasets to gather ecological information can save considerable money and time, providing valuable data for current and emerging issues.
74

Regime de distúrbio e dinâmica da regeneração natural na Floresta Pluvial Atlântica Submontana / Disturbance regime and natural regeneration dynamics in the Lower Montane Atlantic Rain Forest

Renato Augusto Ferreira de Lima 19 April 2007 (has links)
Em uma parcela permanente de 10,24 ha na Floresta Pluvial Atlântica Submontana do Parque Estadual Carlos Botelho (Sete Barras, SP, Brasil), este estudo teve o intuito de descrever o regime de distúrbio do dossel e avaliar a regeneração natural sob diferentes regimes de luz. Para tanto, foi realizado o levantamento de todas as clareiras da parcela, que foram mensuradas e tiveram sua idade aproximada estimada. Em seguida, foram instaladas 42 parcelas de 10x10m para avaliar a regeneração natural em três regimes luminosos: dossel contínuo (18 parcelas), clareiras pequenas a médias (11) e clareiras grandes com abundância de Guadua tagoara (Nees) Kunth (13). O regime de luz foi caracterizado por fotografias hemisféricas tomadas ao centro das parcelas. O estudo da regeneração natural foi divido em: estrato herbáceo (i.e., ervas menores que um metro de altura), avaliado através da cobertura do solo estimada pelo método de interceptação de linha; e estrato arbustivo, avaliado através dos indivíduos com altura maior que 1m, e com diâmetro à altura do peito menor que 5cm. Para estes indivíduos anotou-se a espécie, diâmetro, altura total e área de copa, além da presença de partes reprodutivas e substrato de germinação. Informações sobre hábito, grupo sucessional e síndrome de dispersão das espécies também foram obtidas. Após um ano, uma reavaliação permitiu analisar a mortalidade, danos, recrutamento e crescimento. Apesar de 67% das clareiras terem sido menores que 150 m2 , o regime de distúrbio foi atípico, principalmente pela contribuição de clareiras maiores que 750 m2 , e pela área média e total que variaram respectivamente de 419 a 799 m2 , e de 26 a 49%, dependendo do método de delimitação de clareira. A densidade foi de 6 clareiras.ha -1 e a taxa de recorrência variou entre 91 e 220 anos, dependendo dos métodos. Houve diferença significativa entre os ambientes para a maioria dos índices de luz, especialmente para a radiação total incidente com médias entre 909 e 2.400 mols.m-2.ano-1. Observou-se diferença significativa entre ambientes na cobertura por ervas, porém os resultados variaram entre espécies. No estrato arbustivo, houve diferença significativa na composição e abundância das espécies, inclusive entre clareiras médias e sub-bosque. A densidade de ervas e arbustos foi maior nos ambientes mais iluminados, assim como a densidade de pioneiras e secundárias iniciais. O recrutamento em um ano (16%) apresentou diferenças nos ambientes, com 63% dos recrutas apenas nas grandes clareiras. O mesmo não ocorreu com a taxa de mortalidade cujas principais causas foram os danos físicos e dessecamento. Para os 13% de indivíduos danificados em um ano, houve destaque para danos ligados à extração de palmito. Apenas os danos físicos naturais apresentaram diferença entre ambientes, com grandes clareiras sendo as mais danosas. No geral e entre as 25 espécies avaliadas separadamente, houve uma tendência de crescimento maior com o aumento da incidência luminosa. Clareiras pequenas a médias tiveram significativamente maior riqueza, diversidade e menor dominância de espécies que o sub-bosque. Clareiras grandes com bambu tiveram menor riqueza e diversidade, mas contribuíram com a manutenção da diversidade beta da parcela permanente. / In a 10.24 ha permanent plot of Tropical Lower Montane Atlantic Rain Forest in the Carlos Botelho State Park (Sete Barras, SP, Brazil), this study aimed to describe the canopy disturbance regime and to assess natural regeneration under different light regimes. In order to do so, the plot was completely surveyed for canopy gaps that were measured and had their approximate age estimated. Then, 42 10x10 m plots were established to evaluate natural regeneration under three light regimes: understory (18 plots), small to medium canopy gaps (11 plots) and large gaps abundant in Guadua tagoara (Nees) Kunth (13 plots). The light regime was characterized through hemispherical photographs taken at each plot center. Natural regeneration was dived into: herb stratum (i.e., herbs below one meter in height) assessed through soil coverage using the line intercept method; and shrub stratum or all plant individuals taller than one meter high and thinner than 5 cm in diameter at breast height. All individuals were identified to species and measured for diameter, height, crown height and area, besides notes on the presence of reproductive structures and germination substrate. Information on growth form, dispersal syndrome and ecological group were also obtained for each species. After one year, one reevaluation was made to assess mortality, damages, recruitment and growth. Although 67% of gaps were smaller than 150 m2 , the plot disturbance regime was atypical mainly by the contribution of gaps bigger than 750 m2 and by the average and total gap area that varied respectively from 419 to 799 m2 , and from 26 to 49% depending on the gap delimitation method. Gap density was 6 gaps.ha-1 and the turnover rate varied from 91 to 220 years depending on the gap method employed. There was significant difference between environments among the light index, especially for total incident radiation with means varying from 909 and 2,400 mols.m-2.y-1. It was found significant differences on herb soil coverage between environments, although the results varied among species. In the shrub stratum, species composition and abundance was significantly different, even between small to medium canopy gaps and the understorey. Herb and shrub densities were bigger in the more enlightened environments, as well as pioneer and early secondary species densities. Recruitment over the year (16%) was different between environments with large gaps accounting for 63% of all recruits. Similar difference was not found for mortality rate that had physical damage and desiccation as main death causes. Amid the 13% of damage individuals in the course of one year, there was noticeable contribution of damages linked to illegal extraction of palm-heart. Differences between environments were present only for physical damages with large gaps being the most damaging environment. In general and among the 25 species evaluated separately, there was a tendency of bigger growth with enhancement in light incidence. Small to medium gaps had significantly higher species richness and diversity, and lower dominance compared to the understorey. Large gaps had lower richness and diversity, but they contributed to maintain beta diversity of the permanent plot.
75

Mata ciliar em processo de recuperação no baixo Rio São Francisco : florística e fitossociologia / Riparian forest in recovery process in the lower São Francisco River : floristic and phytosociology

Matos, Gilda Maria do Amarante 31 August 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the state of Sergipe, few floristic and phytosociological studies have been conducted in areas of Riparian Forest. This study was conducted in order to characterize the floristic composition and phytosociological structure of a plant community in riparian area during recovery process, at Mother Nature Farm in Santana de São Francisco - Sergipe. The vegetation object of study is the result of a pilot project that used heterogeneous planting of native tree species, which aimed to obtain data to support future models of restoration in riparian degraded areas in the Lower São Francisco River region. Therefore, there was soil analysis in the area for comparison with ground data performed at the time of implementation of the initial project, floristic and phytosociological survey, with the analysis of horizontal and vertical structure, diversity index of Shannon-Weaver (H '), evenness index Peilou (J'), canopy cover (CC), floristic similarity and dispersion and successional groups syndrome. For phytosociological study of the shrubby- arboreous stratum was conducted a census of individuals present in an area of 1.66 ha, where we sampled all living individuals with bole girth at the level of 1.30 cm (CAP) ≥ 6 cm. The floristic survey of the area for all habits had total richness of 165 species, 133 genera and 51 families, with predominance of herbaceous species, represented by 44.8% of the identified species. Herbaceous families with the highest species richness were Malvaceae (16.7%), Cyperaceae (13.7%), Asteraceae (11%), Fabaceae (8.2%) Poaceae (6.8%), which together represent 56.4% of the richness in herbaceous species recorded in the area. A total 1640 individuals were sampled, belonging to 52 species, 44 genera and 20 families. Through the survey of the natural regeneration of shrub and tree species in the area, were identified individuals belonging to 70 species (38.6% and 61.4% shrubs trees), 58 genera and 25 families. Of these 70 species sampled, 57 species were not derived from planting and thus from the natural regeneration duct through dispersion. With respect the absolute density estimated was 1,025 ha-1 subjects with basal area of 9.79 m2 / ha, average individual diameter of 6.53 cm and average height of 5.65 m. Families who contributed to this floristic richness were Fabaceae, with 17 species, Anacardiaceae with five species, Rubiaceae with four species, Euphorbiaceae and Myrtaceae with three each, Capparaceae, Meliaceae, Polygonaceae, Salicaceae and Sapindaceae with two species each, the remaining families presented only one species each. The species Mimosa caesalpiniifolia Benth. with 2,70 m2 of basal area was the one with the highest values in all phytosociological parameters analyzed, a fact that may indicate a greater adaptation of species to the environment or ecological dominance of this kind. The diversity index Shannon-Wiener (H ') for sampling with 1.640 individuals was 2.78 nats / ind., the evenness index of evenness (J') of 0.70, Jentsch mix coefficient was 0.032 and Simpson's dominance index found was 0.135. The area has a high diversity of species and high dominance. The species in the study area were grouped into three categories dispersion (zoochorous, anemochoric and autochorous) and two series of categories (pioneer and climax). From these ratings was obtained 31 species (59.62%) classified as zoochorous, with 18 pioneer and 13 climax; 15 autochorous species (28.85%), with 12 pioneer and 3 climax; six anemochoric (11.54%), four pioneers and two climax. Independently of analyzed and compared physiognomy, there was a low floristic similarity with other areas of the region. Therefore, all analyzed areas are defined floristic peculiarities. It is also observed that, over the years, recomposing the soil fertility is probably due to increased nutrient cycling and also for vegetation cover which promotes a greater protection of the soil, thereby facilitating the establishment of new species in the area. / Em Sergipe, poucos estudos florísticos e fitossociológicos têm sido realizados em áreas de Matas Ciliares. O presente estudo foi realizado com o objetivo de caracterizar a composição florística e a estrutura fitossociológica de uma comunidade vegetal em área de mata ciliar, em processo de recuperação, na Fazenda Mãe Natureza em Santana do São Francisco - Sergipe. A vegetação objeto do estudo é resultado de um projeto-piloto que utilizou o plantio heterogêneo de espécies arbóreas nativas, que visou obter dados para subsidiar futuros modelos de restauração de áreas de mata ciliar degradadas na região do Baixo Rio São Francisco. Para tanto, realizou-se análise do solo da área para comparação com os dados do solo realizados na época da implantação do projeto inicial, levantamento florístico e fitossociológico, com a análise da estrutura horizontal e vertical, índice de diversidade de Shannon-Weaver (H’), índice de equabilidade de Peilou (J’), cobertura de copa (CC), similaridade florística e síndrome de dispersão e grupos sucessionais. Para o estudo fitossociológico do estrato arbustivo-arbóreo foi realizado o censo dos indivíduos presentes numa área de 1,66 ha, onde foram amostrados todos os indivíduos vivos com circunferência do caule ao nível de 1,30 cm (CAP) ≥ 6 cm. O levantamento florístico da área para todos os hábitos apresentou riqueza total de 165 espécies, 133 gêneros e 51 famílias, havendo predominância das espécies herbáceas, representadas por 44,8% das espécies identificadas. As famílias herbáceas que apresentaram maior riqueza de espécies foram Malvaceae (16,7%), Cyperaceae (13,7%), Asteraceae (11%), Fabaceae (8,2%) Poaceae (6,8%), que juntas representam 56,4% da riqueza em espécies herbáceas registradas na área. Através do levantamento da regeneração natural das espécies arbustivo-arbóreas da área, foram identificados indivíduos pertencentes a 70 espécies (arbustos 38,6% e 61,4% árvores), 58 gêneros e 25 famílias. Destas 70 espécies amostradas, 57 espécies não foram oriundas do plantio sendo, portanto, provenientes da regeneração natural via dispersão. Para o levantamento estrutural da área, foi mensurado um total 1.640 indivíduos, pertencentes a 52 espécies, 44 gêneros e 20 famílias. A densidade absoluta, estimada foi de 1.025 indivíduos ha-1 com área basal de 9,79 m2/ ha, diâmetro médio individual de 6,53 cm e altura média de 5,65 m. As famílias que mais contribuíram para essa riqueza florística foram Fabaceae, com 17 espécies, Anacardiaceae com cinco espécies, Rubiaceae com quatro espécies, Euphorbiaceae e Myrtaceae com três cada, Capparaceae, Meliaceae, Polygonaceae, Salicaceae e Sapindaceae com duas espécies cada, as demais famílias apresentaram apenas uma espécie cada. A espécie Mimosa caesalpiniifolia Benth., com 2,70 m2 de área basal foi a que apresentou os maiores valores em todos os parâmetros fitossociológicos analisados, fato este que pode indicar uma maior adaptação da espécie ao ambiente ou dominância ecológica desta espécie. O índice de diversidade de Shannon-Wiener (H’) para a amostragem com 1640 indivíduos foi de 2,78 nats/ind., o índice de Equabilidade de Pielou (J’) de 0,70, o Coeficiente de Mistura de Jentsch foi de 0,032 e o índice de dominância de Simpson encontrado foi 0,135. A área apresenta uma alta diversidade de espécies e alta dominância. As espécies da área em estudo foram agrupadas em três categorias de dispersão (zoocóricas, anemocóricas e autocóricas) e duas categorias de sucessão (pioneiras e clímax). A partir dessas classificações obteve-se 31 (59,62%) espécies classificadas como zoocóricas, sendo 18 pioneiras e 13 clímax, 15 (28,85%) espécies autocóricas, sendo 12 pioneiras e 3 clímax, e seis (11,54%) espécies anemocóricas, sendo quatro pioneiras e duas clímax. Independente da fisionomia analisada e comparada, observou-se uma baixa similaridade florística com outras áreas da região. Assim, todas as áreas analisadas apresentam particularidades florísticas definidas. Observa-se também que, ao longo dos anos, o solo está recompondo sua fertilidade, provavelmente devido à maior ciclagem de nutrientes e também pela cobertura da vegetação que promove uma maior proteção do solo, facilitando assim o estabelecimento de novas espécies na área. / São Cristóvão, SE
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Avaliação dos efeitos do tratamento crônico com neurolépticos e sua interação com substâncias potencialmente antioxidantes sobre parâmetros de estresse oxidativo no fígado e rim de ratos / Assessment of the effects of chronic treatment with neuroleptics and their interaction with potentially antioxidants substances on oxidative stress parameters in liver and kidney of rats

Corte, Cristiane Lenz Dalla 27 March 2008 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Treatment with neuroleptic drugs has been associated to side effects like tardive diskynesia and hepatic damage. In spite of the several reports of hepatotoxicity after neuroleptic administration, few data are available in the literature about these effects and the precise mechanisms by which neuroleptics induce hepatotoxicity remain unclear. In the same way, there are few studies about the effects of neuroleptics on kidney. In this way, the first aim of the present work was to assess the effects of chronic exposure to fluphenazine in liver and kidney of rats, as well as the protective effect of diphenyl diselenide on the fluphenazine-induced damage (article 1). Long-term treatment with fluphenazine caused an increase in lipid peroxidation levels in liver and kidney homogenates, a decrease in hepatic SOD activity, and an increase in hepatic CAT activity. Diphenyl diselenide was able to protect liver and kidney from lipid peroxidation, ameliorate SOD activity in liver, and prevent the increase in hepatic CAT activity. Diphenyl diselenide treatment did not affect δ-ALA-D activity, but fluphenazine and/or in combination with diphenyl diselenide showed an inhibitory effect on δ-ALA-D activity in liver and kidney. The second objective of this study was to determine whether the treatment with haloperidol (HP), valerian or both in association impairs liver or kidney functions (article 2). Valerian did not affect oxidative stress parameters in the liver or kidney of rats. HP only increased glutathione (GSH) depletion in liver, but not in kidney. However, when HP was associated with valerian, an increase in lipid peroxidation levels and reactive species production was observed in the hepatic tissue. HP and valerian when administered independently did not affect the activity of hepatic and renal δ-ALA-D, however, these drugs administered concomitantly provoked an inhibition of hepatic δ-ALA-D activity. Serum aspartate aminotransferase (AST) activity was not altered by any treatment. However, serum alanine aminotransferase (ALT) activity was higher in the HP group and HP plus valerian group. Taken together, these results indicate the relationship between the treatment with flufenazine and the oxidative stress, and also point to the protective role of diphenyl diselenide on the oxidative damage induced by fluphenazine in liver. Our data also suggest adverse interactions between haloperidol and valerian treatments causing hepatic damage related to oxidative stress. / O tratamento com drogas neurolépticas tem sido associado a efeitos colaterais como a discinesia tardia (DT) e o dano hepático. Apesar dos inúmeros casos de hepatotoxicidade após a administração de neurolépticos, são escassos os dados na literatura a respeito desses efeitos e o mecanismo exato pelo qual neurolépticos induzem hepatotoxicidade permanece incerto. Da mesma forma, existem poucos estudos relatando os efeitos dos neurolépticos sobre o rim. Dessa forma, o primeiro objetivo deste trabalho foi avaliar os efeitos da exposição crônica à flufenazina em fígado e rim de ratos bem como o efeito protetor do disseleneto de difenila sobre o dano induzido por flufenazina (artigo 1). O tratamento prolongado com flufenazina causou um aumento na peroxidação lipídica no fígado e no rim, uma diminuição na atividade da SOD hepática, e um aumento na atividade da CAT hepática. O disseleneto de difenila foi capaz de proteger o fígado e o rim da peroxidação lipídica, melhorou a atividade da SOD no fígado, e preveniu o aumento na atividade da CAT no fígado. O tratamento com disseleneto de difenila não afetou a atividade da δ-ALA-D, mas a flufenazina e/ou em combinação com disseleneto de difenila demonstrou ter efeito inibitório sobre a atividade da δ-ALA-D no fígado e no rim. O segundo objetivo deste estudo foi determinar se o tratamento com haloperidol (HP), valeriana ou a associação de ambas as drogas pode alterar as funções hepáticas e renais (artigo 2). A valeriana não afetou nenhum parâmetro de estresse oxidativo no fígado e no rim dos ratos. O HP apenas aumentou a depleção de glutationa (GSH) no fígado, mas não no rim. Entretanto, quando o HP foi associado com a valeriana, um aumento na peroxidação lipídica e produção de espécies reativas foram observados no tecido hepático. HP e valeriana quando administrados independentemente não afetaram a atividade da δ-ALA-D hepática e renal, contudo, quando estas drogas foram administradas concomitantemente provocaram uma inibição da atividade da δ-ALA-D hepática. A atividade da aspartato aminotransferase (AST) do soro não foi alterada por nenhum dos tratamentos. No entanto, a atividade da alanina aminotransferase (ALT) do soro estava aumentada nos grupos tratados com HP e HP mais flufenazina. Juntos estes resultados indicam uma relação entre o tratamento com flufenazina e o estresse oxidativo, e também apontam para o papel protetor do disseleneto de difenila no dano oxidativo induzido por flufenazina no fígado. Nossos dados também sugerem interações adversas no tratamento com haloperidol e valeriana, ocasionando dano hepático associado ao estresse oxidativo.
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Herb layer characteristics, fly communities and trophic interactions along a gradient of tree and herb diversity in a temperate deciduous forest / Krautschichteigenschaften, Fliegengesellschaften und trophische Interaktionen entlang eines Baum- und Krautartengradienten in einem temperaten Laubwald

Vockenhuber, Elke 16 August 2011 (has links)
No description available.
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Modèle expérimental de fibrose rénale interstitielle induite par les acides aristolochiques (plantes chinoises)

Debelle, Frédéric 01 February 2005 (has links)
La néphropathie aux plantes chinoises (CHN) est une maladie rénale grave qui a été décrite pour la première fois en 1993 chez des patientes ayant suivi un régime amaigrissant à base d’extraits de plantes chinoises (Aristolochia fangchi) contenant des acides aristolochiques (AA). Cette néphropathie se caractérise par une atrophie tubulaire et une fibrose interstitielle aboutissant à l’urémie terminale et se complique fréquemment de cancers des voies urinaires. Au moment d’initier ce travail, il subsistait toujours un large débat quant au rôle étiologique réel des acides aristolochiques dans la genèse de cette maladie. En effet, les gélules à visée amaigrissante contenaient d’autres substances potentiellement néphrotoxiques. Mais surtout, il n’existait aucune preuve expérimentale que les AA pouvaient induire une fibrose rénale interstitielle.<p>Dans la première partie de ce travail, nous démontrons que l’injection par voie sous-cutanée d’AA à la dose de 10 mg/Kg/jour à des rats Wistar mâles en déplétion sodée entraîne l’apparition au 35ème jour d’une atrophie tubulaire, d’une fibrose interstitielle et d’une insuffisance rénale, reproduisant ainsi les anomalies caractéristiques de la CHN. Nous avons ensuite montré que la dexfenfluramine, substance anorexigène à action de type sérotoninergique prise concomitamment par les patientes atteintes de CHN, ne potentialise pas la toxicité rénale des AA. Enfin, la stimulation du système rénine angiotensine (SRA) par la déplétion sodée ou l’inhibition de celui-ci par un traitement pharmacologique ne modifie pas la fibrose interstitielle ni l’insuffisance rénale induite par les AA.<p>En conclusion, nous avons réussi à développer un modèle in vivo de fibrose rénale interstitielle induite par les AA. Dès lors nous avons apporté la preuve expérimentale de l’implication des AA dans le développement de la CHN. Ce modèle a permis de démontrer que les autres éléments potentiellement néphrotoxiques contenues dans la cure d’amaigrissement (dexfenfluramine, diurétique, laxatif) n’influençaient pas l’évolution de la fibrose interstitielle, ce qui confirme que la prise isolée d’AA suffit à expliquer le développement de la CHN. Cette confirmation à d’importantes implications en santé publique dans la mesure où des plantes contenant des acides aristolochiques font toujours partie des phytothérapies traditionnelles. De plus, il est apparu que, dans ce modèle, les mécanismes de la fibrose rénale interstitielle pouvaient être largement indépendants du SRA. Enfin, de par sa durée limitée et sa grande reproductibilité, ce modèle constitue un outil expérimental d’avenir pour l’étude des mécanismes physiopathologiques de la fibrose rénale interstitielle en général.<p> / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished

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