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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.
81

Absorção de metais pesados de solos contaminados do aterro sanitário e Pólo Industrial de Manaus pelas espécies de plantas Senna multijuga, Schizolobium amazonicum e Caesalpinia echinata.

Chaves, Edson Valente 28 April 2008 (has links)
Made available in DSpace on 2015-04-20T12:31:38Z (GMT). No. of bitstreams: 1 Tese Edson Valente.pdf: 791720 bytes, checksum: 2b118211a5c89a68aa642ece2e2d7af3 (MD5) Previous issue date: 2008-04-28 / Fundação de Amparo à Pesquisa do Estado do Amazonas / Heavy metals accumulate up frequently in the top layer of soil on the roots accessible principles of the plants. In advanced stages of infection may reach decimate the biota or even present concentrations thousands of times higher than in the aquatic system. This is due to changes in its chemical forms allowing the build up in living organisms. This study evaluated is the behavior of the species Senna multijuga, Caesalpinia echinata and Shizolobium amazonicum in soils contaminated by heavy metals from landfill (ASC) and Manaus Industrial Pole (PIM). The study was conducted in a greenhouse for five months. In soil, were analyzed the chemical and physical attributes and concentration of heavy metals by atomic absorption spectrometry, (FAAS) in the air-acetylene flame in fractions exchangeable, carbonate, iron/manganese oxide and organic matter. The plant, the parties were separated and air root, dried at 65 °C, digested with HNO3 and HClO4 (4:1) at 200 °C for two hours and the concentrations of heavy metals determined by FAAS. The results showed that the metals have different distributions in contaminated soil, being influenced by factors such as pH, CEC, amount of organic matter, complexation, competition ion and chemical interactions that contributed to their mobility and/or adsorption. The hierarchical analysis (HCA) and major components (PCA) revealed a similarity between the soils and with strong relationships between Cd, Co, Cr, Mn, in the soil of the ASC and Cd, Cu, Mn, Ni, Pb and Zn in the soil the PIM. The hierarchical analysis (HCA) and major components (PCA) revealed a similarity between the soils and with strong relationships between Cd, Co, Cr, Mn, in the soil of the ASC and Cd, Cu, Mn, Ni, Pb and Zn in the soil the PIM. The species multijuga Senna was the best that it was developed in contaminated soil. The Caesalpinia echinata has potential accumulator to the elements Mn and Zn. The three species can be classified as fitoextratora and hiperacumuladora for Co, Cd, Cu, Ni, Mn, Fe, Cr, Zn and Pb, regardless of the soil analyzed. / Os metais pesados se acumulam freqüentemente na camada superior do solo, ficando acessíveis as raízes das plantas. Em estágios avançado de contaminação podem chegar dizimar a biota ou, mesmo apresentar concentrações milhares de vezes maiores do que no sistema aquático. Isso ocorre devido às mudanças nas suas formas química possibilitando o acúmulo em organismos vivos. Neste trabalho avaliaram-se o comportamento das espécies Senna multijuga, Caesalpinia echinata e Shizolobium amazonicum em solos contaminados por metais pesados do aterro sanitário de Manaus (ASC) e Pólo Industrial de. Manaus (PIM). O estudo foi desenvolvido em casa de vegetação durante cinco meses. No solo, foram analisados os atributos químicos e físicos e concentração dos metais pesados por espectrometria de absorção atômica (FAAS) em chama aracetileno nas frações trocável, carbonácea, oxídica e matéria orgânica. Nas planta, foram separadas as partes aéreas e radiculares, secas a 65 oC, digeridas com HNO3 e HClO4 (4:1) a 200 oC por duas horas e as concentrações de metais pesados determinadas por FAAS. Os metais possuem distribuições diferentes nos solos contaminados, sendo influenciados por fatores como pH, capacidade de troca catiônica (CTC), quantidade de matéria orgânica, complexação, competição iônica e interações químicas que contribuíram para sua mobilidade e/ou adsorção. As análises hierárquica (HCA) e componentes principais (PCA) revelaram uma similaridade entre os solos estudados e com relações fortes entre Cd, Co, Cr e Mn, no solo do ASC e Cd, Cu, Mn, Ni, Pb e Zn no solo do PIM. A espécie Senna multijuga foi a que melhor se desenvolveu nos solos contaminados. A Caesalpinia echinata possui potencial acumulador para os elementos Mn e Zn. As três espécies podem ser classificadas como fitoextratora e hiperacumuladora para Co, Cd, Cu, Ni, Mn, Fe, Cr, Zn e Pb, independentemente dos solos analisados.
82

Análise fitossociológica do sub-bosque de florestas com araucária e sua relação fitogeográfica com outras formações da Floresta Atlântica s.l. / Understory phytosociological analysis of forests with araucaria and its phytogeographic relation with other phytogeographic of the s.l. Atlantic Forest formations

Polisel, Rodrigo Trassi, 1986- 19 August 2018 (has links)
Orientador: Kikyo Yamamoto / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T19:37:53Z (GMT). No. of bitstreams: 1 Polisel_RodrigoTrassi_M.pdf: 6584515 bytes, checksum: 2fed8a2ee1f4e876bf20ab3234436559 (MD5) Previous issue date: 2011 / Resumo: O foco desta dissertação é o sub-bosque da floresta com araucária. Estudos com o seu componente arbóreo têm mostrado que esta formação possui uma área core no sul do Brasil, com limite no sul do estado de São Paulo. Entretanto, ainda não se sabe se o componente de sub-bosque corrobora esta delimitação fitogeográfica. Esta dissertação pretende contribuir para o conhecimento do sub-bosque de floresta com araucária e a sua delimitação fitogeográfica perante as demais formações florestais da Floresta Atlântica. A uma matriz de dados de espécies de sub-bosque pré-existente, acrescentamos novos dados, inclusive dos inventários que realizamos em quatro trechos de floresta com araucária em São Paulo, dois na presumida área core, Barra do Chapéu ("BC?: 24º28?19??S e 49º01?48??W; 803 msm) e Itaberá ("IT?: 23º50?55??S e 49º08?27??W; 705 msm); e dois em áreas disjuntas, Bananal ("BA?: 22º45?34''S e 44º18'53''W; 1011 msm) e Campos do Jordão ("CJ?: 45º27'52''W e 22º41'30''S; 1500 msm). Em cada localidade, dentro de cada uma das 50 parcelas contíguas previamente instaladas de 10 x 20 m (1 ha) (exceto em Bananal: 43 parcelas, 0,86 ha), alocamos cinco subparcelas de 1 x 1 m nas quais registramos dados florísticos e estruturais dos componentes residentes do sub-bosque: bambusóides, ervas, subarbustos, arbustos, trepadeiras e pequenas árvores. Análises multivariadas aplicadas a dados florísticos das regiões sul e sudeste do Brasil não permitiram o claro reconhecimento de espécies peculiares ao sub-bosque residente de Floresta Ombrófila Mista (FOM). Aparentemente por razões climáticas, localidades ao sul de Torres (RS) (grupo sul-rio-grandense), exceto o nordeste do estado, se separaram das demais localidades ao norte na Serra do Mar. O clima estacional distinguiu um terceiro bloco. As florestas com araucária do sul do país se aproximaram do "grupo sul-rio-grandense?. Localidades de FOM do Paraná e Santa Catarina se agruparam na TWINSPAN, mas apenas parcialmente na UPGMA. Este agrupamento pode representar a região core de distribuição das espécies de sub-bosque da floresta com araucária, mas demanda confirmação, pois o número de estudos nestes locais ainda é baixo. As florestas com araucária de São Paulo apresentaram-se similares às florestas estacionais do entorno. Dentro do estado de São Paulo, as quatro localidades que descrevemos separaram-se como blocos florísticos distintos. Campos do Jordão apresentou a área mais homogênea. Itaberá apresentou a maior heterogeneidade entre parcelas, aparentemente relacionada à variação de luz proporcionada pela caducifolia das árvores do dossel. Análise da curva de rarefação mostrou que Bananal, Campos do Jordão e Barra do Chapéu possuem riqueza e diversidade semelhantes e maiores que em Itaberá. Ervas e arbustos apresentaram riqueza e abundância estatisticamente maiores em Campos do Jordão e Bananal, enquanto que Barra do Chapéu e, principalmente, Itaberá se destacaram pela abundância de trepadeiras. Não se observou relação entre riqueza de espécies ruderais e o estado aparente de conservação das áreas. Duas novas espécies registradas, uma em Bananal e outra em Campos do Jordão, evidenciaram o conhecimento ainda falho sobre o sub-bosque da Floresta Atlântica, o que dificulta a análise da delimitação fitogeográfica das suas fitofisionomias / Abstract: The focus of this dissertation is the understory of Araucaria forest. Studies with its tree component have shown that this formation has a core area in southern Brazil, with a limit in the southern São Paulo state. However, it is not yet known if the understory component supports this phytogeographic delimitation. This thesis aims to contribute to the knowledge of the understory of Araucaria forest and its phytogeographical delimitation regarding other Atlantic Forest formations. We added new data to a pre-existing data matrix of understory species, including those of floristic and phytosociological inventories we carried out in four patches of Araucaria forest in São Paulo, two in the presumed core area, Barra do Chapéu ('BC ': 24 ° S and 49 º 28'19' 01'48''W, 803 msm) and Itaberá (' IT ': 23 ° S and 49 º 50'55' 08'27''W, 705 msm) and two in disjunct areas, Bananal ('BA': 22 ° S and 44 º 45'34' 18'53''W; msm 1011) and Campos do Jordão ('CJ': 45 ° and 22 ° 27'52''W 41'30''S, 1500 msm). At each location, within each of the previously installed 50 plots of 10 x 20 m (1 ha) (except in Bananal: 43 plots, 0.86 ha), we allocated five subplots of 1 x 1 m. Within the subplots, we recorded floristic and structural data of the understory components: bambuzoids, herbs, subshrubs, shrubs, vines and small trees. Multivariate analyses applied to floristic data from southern and southeastern Brazil did not allow a clear recognition of peculiar understory species of Araucaria forest (AF). Apparently due to climatic factors, locations south of Torres (RS) (gaucho group), excepting the northest state, separated from other northern locations in Serra do Mar. The seasonal climate distinguished a third group. The Araucaria forests in southern Brazil were more similar to the ' gaucho group?. Some AFs from Paraná and Santa Catarina were grouped by TWINSPAN, but not clearly by UPGMA. This group may represent the core distribution area of AF?s understory species, but it requires confirmation because the number of studies in these areas is still low. The AFs in São Paulo showed similarity with the surrounding seasonal forests. Within São Paulo state, the four locations we described behaved as four distinct floristic blocks. Campos do Jordão presented the most homogeneous area. Itaberá presented the greater heterogeneity among plots, apparently due to the variation of light provided by the shedding of canopy trees. Analysis of the rarefaction curve showed that Bananal, Campos do Jordão and Barra do Chapéu have similar richness and diversity, higher than in Itaberá. Herbs and shrubs had higher richness and abundance in Campos do Jordão and Bananal, while abundance of vines distinguished Barra do Chapéu and especially Itaberá. No relationship was found between richness of weed species and the apparent conservation status of the areas. The lack of knowledge about the understory of Atlantic Forest, that complicates the analysis of phytogeographical demarcation of its physiognomies, was demonstrated by two new species we found, one in Bananal and the other in Campos do Jordão / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal
83

Assessing vertical distribution of organic carbon stocks in shallow soils under a bush-encroached rangeland

Masotla, Abel Lesetja January 2021 (has links)
Thesis (M. Sc. Agriculture (Soil Science)) -- University of Limpopo, 2021 / Globally and in most parts of South Africa, there is a trend of increasing shrub encroachment in savanna rangelands. A number of studies have investigated the impact of shrub encroachment on soil organic carbon content (SOC) and soil organic carbon stocks (SOCs) in savannas. So far there is no clear consensus on whether shrub encroachment increases or decreases the level of SOC and SOCs, especially in semi arid savanna grasslands. Furthermore, knowledge on the effects of shrub encroachment on SOCs is largely restricted to the topsoil, as this is the part of the profile influenced by inputs and losses of soil organic matter. How shrub encroachment affects the vertical distribution of SOCs is rarely considered in the existing literature and the edaphic factors controlling SOCs with depth are poorly understood. The objectives of this study were (i) to quantify the vertical distribution of SOC and SOCs and (ii) to identify the edaphic factors controlling the vertical distribution of SOC and SOCs in a shrub-encroached savanna grassland sited on shallow plinthic soil. To achieve the objectives, a vegetation and soil survey of the savanna grassland was conducted whereby sampling areas were demarcated and characterized into open and shrub encroached grassland plots. In each encroachment level, three pits were randomly dug to the limiting layer on plots sited on the same soil type and similar topographic position. Soil samples were collected from the pits at depth intervals of 0-10, 10-20, 20-30, 30-40, 40-50, 50-60 and 60-70 cm. The collected soil samples were analyzed for chemical and physical properties in the laboratory. Correlation analysis was carried out to determine the relationship between SOC and SOCs, which were the variables of interest in this study and related controlling soil physicochemical properties. The results showed that SOC was significantly greater (P<0.05) in the shrub-encroached grassland compared to open grassland. Furthermore, the results revealed that SOC was on average 19 and 13% greater in the topsoil (0-20 cm) and subsoil (20-70 cm) of shrub encroached grassland compared to open grassland. The greater SOC in the topsoil of the shrub-encroached grassland was mainly attributed to higher SOC inputs from plant litter and detritus derived from trees and grasses, which are the dominant plant life forms in savannas. In the topsoil, SOC and SOCs were positively correlated with extractable phosphorus (P) (r = 0.60; P < 0.05), while in the subsoil they were positively correlated ix with extractable phosphorus (r = 0.54), soil porosity (r = 0.52), extractable copper (r = 0.46), extractable zinc (r = 0.41), exchangeable calcium (r = 0.37) and negatively correlated with mean weight diameter (r = -0.43). Overall, SOC and SOCs under both shrub-encroached and open grasslands vertically decreased with soil depth. The results obtained highlighted that the factors controlling the level of SOC and SOCs differs in the topsoil and subsoil of the studied shrub encroached grassland. These findings suggest that in the shallow plinthic soil investigated in this study, SOC in the topsoil is controlled by the macronutrient P, while in the subsoil it is physically protected by soil aggregates and chemically stabilized via complexation interactions with exchangeable cations and heavy metals. In-depth understanding of the physico-chemical factors controlling SOC storage is critical to foster management practices that will improve the cycling of SOC in shrub-encroached savanna grasslands.
84

Measurement and Modeling of Fire Behavior in Leaves and Sparse Shrubs

Prince, Dallan R 01 July 2014 (has links) (PDF)
Wildland fuels and fire behavior have been the focus of numerous studies and models which provide operational support to firefighters. However, fuel and fire complexity in live shrubs has resulted in unexpected and sometimes aggressive fire behavior. The combustion of live fuels was studied and modeled, and the results were assimilated into a shrub-scale fire behavior model which assumes fire spread by flame-fuel overlap. Fire spread models have usually assumed that radiation heat transfer is responsible for driving fire spread, but that assumption is a topic of continuing debate, and appears to contradict some experimental observations. A convection-based shrub-scale fire spread model has been developed, building on a heritage of experiments and modeling previously performed at Brigham Young University. This project has (1) characterized fundamental aspects of fire behavior, (2) integrated the resulting submodels of fire behavior into an existing shrub model framework, and (3) produced shrub-scale fire spread experiments and (4) made model comparisons. This research models fire spread as a convection-driven phenomenon and demonstrates strategies for overcoming some of the challenges associated with this novel approach.
85

Habitat Selection in Four Sympatric Small Mammal Species and the Effects of Potential Predators on Peromyscus Leucopus

Chupp, Adam Daniel 01 January 2005 (has links)
I examined the effects of potential predators in relation to habitat selection in Peromyscus leucopus. I also examined habitat selection in three other sympatric species (Blarina brevicauda, Blarina carolinensis, Sorex longirostris). I utilized data fiom 49 sampling sites on National Park Service land; Petersburg National Battlefield Eastern Front Unit (15), Five-Forks Unit (17), Appomattox Court House National Historical Park (15) and Booker T. Washington National Monument (12). Sites were categorized by location (park unit) and habitat type (i.e. bottom-land hardwood), and the microhabitat within each sampling site was characterized by four variables (% cover of grasses, herbs, shrubs, and volume of downed wood). Importance values of tree species within each sampling site were also measured. Peromyscus leucopus, B. brevicauda, B. carolinensis, and S. longirostris were captured in all habitat types. Low capture rates for shrew species and high variability in the abundance of shrew species among all sampling sites were likely responsible for the lack of differences in abundance among habitats (p > 0.05). Peromyscus leucopus represented 76% of the captures among prey species and was the only species to demonstrate differences in relative abundance among habitat types. The relative abundance of P. leucopus was higher in bottom-land hardwood habitat when compared to pine forest plantation habitat (ANOVA, p P. leucopus among these habitat types may be explained by differences in understory structural diversity. Furthermore, the corresponding increase in the relative abundance of Procyon lotor (the most abundant predator during the study) in structurally heterogeneous habitat (bottom-land hardwood) suggests the importance of anti-predator behaviors within these habitat types. Ultimately, this may suggest that prey cannot escape the presence or calculate the abundance of predators and instead simply avoid dangerous habitats. Although the relative abundance of the most abundant predator (P. lotor) and prey (P. leucopus) species were positively associated within certain habitat types, a negative association between predator and prey species abundance was evident within parks. In the Eastern Front unit the relative abundance of prey (P. leucopus, S. longirostris) was lower in comparison to the Five-Forks unit while the abundance of P. lotor was higher (ANOVA, p P. lotor, Didelphis virginiana, and Urocyon cinereoargenteus were higher in the Eastern Front unit when compared to the Five-Forks unit. It appeared that the lethal effects of predators are evident at larger scales (within parks) despite the anti-predator behaviors of prey at smaller scales (within microhabitats). My results indicate that at larger scales (within parks) the lethal effects (removal of prey) of abundant predators may overwhelm the non-lethal effects (anti-predator behavior) exhibited by prey at smaller scales, especially in areas where structurally heterogenous habitats are lacking.
86

Shrub encroachment of temperate grasslands: Effects on plant biodiversity and herbage production

Kesting, Stefan 19 November 2009 (has links)
No description available.
87

Zakládání a následná mechanizovaná údržba biocenter jako prvku ekologické stabilizace krajiny. / The foundation and subsequent mechanized maintenance of biocentres as an element of landscape ecological stability

DOHNALOVÁ, Tereza January 2012 (has links)
The work drala with the theoretical design bio-centers, the composition of vegetation in it and machanization means with which it could be bulit bio-center. The theoretical part contains the characteristics of concepts, the characteristics for which the proposed bio-center and track stands. The practical part contains procedures for setting up bio-centers, design of machinery and design of care of forests based on bio-centers.
88

Análise da vegetação em um fragmento de caatinga no município de Porto da Folha, Sergipe, Brasil

Oliveira, Diogo Gallo de 26 June 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This research was conducted in a fragment of Caatinga with around 50 ha in São Pedro farm, located at Porto da Folha City, Sergipe, order to know the floristic composition and phytossociological structure of herbaceous and shrub-tree components, verify the relationships physiognomic of the shrub-tree with other Caatinga areas, as well as the existence of edge effect in the fragment studied, with the intention of generate subsidies to studies of ecology, conservation and recovery of degraded areas in the region. Thus, it was tested the following null hypotheses: 1st - there is no difference in the structure and richness of shrub-tree of fragment studied in comparison with other areas of Caatinga analyzed in Sergipe and in the Northeast; 2nd - there is no difference in the floristic composition and phytossociological structure of herbaceous vegetation between two seasons (dry and wet); 3rd - there is no difference in the floristic composition and structure of the shrub-tree between edge and interior of the fragment Caatinga studied. For testing the first hypothesis, it was conducted sampling of shrub- tree through of 25 plots, with 20x20m (400m²), distributed systematically at intervals of 141 m in two directions perpendicular to each plot. All individuals of shrubs-trees were identified and recorded with at breast height circumference (BHC at 1.30 m from ground level) ≥ 6.0 cm and analyzed the floristic composition, the phytossociological structure (density, frequency, dominance and importance value), diversity in addition to spatial distribution and floristic similarity. Species richness and structural parameters of the component of shrubs-trees found in the fragment studied was higher than in most surveys in other areas of Caatinga dominium, considering the different types analyzed ( Caatinga Caducifólia Espinhosa , Caatinga Caducifólia Não Espinhosa and Vegetação Estacional Decidual ). The vegetation that was in the fragment studied can be classified as Caatinga Caducifólia Espinhosa (Caatinga sensu stricto) showed the highest similarity to other semiarid areas that have this same type of plant formation. For testing the second hypothesis, two samples were realized of the herbaceous component for comparison, in the rainy season and one during the dry season on 25 smaller plots with 1x1 m (1m ²) distributed systematically within plots of 20x20m, a distance of 10 meters, following is the angle of 45° from the first vertex of each plot. All living plants were measured and identified with stem/pseudo-stem chlorophyll with absence or low level of lignifications that were not seedlings of woody species and analyzed the floristic composition, the phytossociological structure (density, frequency, dominance and importance value), diversity in addition to life forms of Raunkiaer. The density, frequency, dominance and importance value of herbaceous populations, as well as height and diameter of plants were low in the dry season. The diversity of herbaceous species recorded for the fragment was more than most of the studies that was done in other areas of Caatinga of Northeast Brazil, which can be associated to good state of conservation of the studied fragment. The life-form predominant of vegetation was the therophytes, followed by phanerophytes, featuring a therophytic phytoclimate to the region of the study area. The analysis of structural patterns and diversity conducted only in two distinct seasons are not enough to know, in detail, the ecological dynamics of the herbaceous component of caatinga in the fragment studied. For test the third hypothesis were selected 24 permanent plots with 20x20 m, being 12 marked in the edge and 12 inside the fragment, in a systematic manner, at intervals of 141 m. In each plot were identified and recorded all individuals of shrubs and trees with at breast height circumference (BHC at 1.30 m from xii ground level) ≥ 6.0 cm and measured variables dendrometric for the calculations of diversity and structure, addition to these variables was calculated leaf area index using hemispherical photos with the lens "fisheye" 180 ° in the center of each plot. We used non-metric multidimensional scaling (NMDS) to check whether there are differences in species composition between plots of the edge and interior. To determine the floristic similarity between plots evaluated in different environments, we used the similarity analysis (ANOSIM). Differences between the sampled environmental variables (dependent variables) in relation to the location of the edge and interior plots (independent variable) were tested using generalized linear models (GLM's). The plots of edge presented 43 species and 1157 individuals, while the interior of the 1377 individuals and 42 species. The NMDS ordination showed that there are not clear differences in species composition between the two environments analyzed (edge and interior). The five structural parameters vegetation analyzed between plots located the edges and interior the fragment (tree height, stem diameter, basal area, number of individuals and leaf area index) did not result in statistically significant differences. In relation to the richness, diversity species and evenness indexes was verified also that there is no statistically significant difference between the environment the edge and interior. The physiognomic and structural similarities of vegetation in the study area, evidenced by the richness, abundance and distribution of species in different locations (edge and interior), suggest the existence of a common pattern, possibly related to the availability of resources in an equitable manner (as light, water and nutrients), history of conservation of the vegetation of the fragment, as well as the heterogeneity and complexity of the environmental area. Indicating that the community arbustivo-arboreal of the fragment of Caatinga studied is not ecologically affected by the presence of the edges. / O presente trabalho foi realizado em um fragmento de Caatinga com aproximadamente 50 ha, pertencente à fazenda São Pedro, localizada no município de Porto da Folha, Sergipe, objetivando conhecer a composição florística e a estrutura fitossociológica do componente herbáceo e arbustivo-arbóreo, verificar as relações fitofisionômicas do estrato arbustivo-arbóreo com outras áreas de Caatinga, bem como a existência de efeito de borda no fragmento estudado, com o intuito de gerar subsídios aos estudos de ecologia, conservação e recuperação de áreas degradadas na região. Deste modo foram testadas as seguintes hipóteses nulas: 1ª - não existe diferença na riqueza e estrutura da vegetação arbustivo-arbóreo do fragmento estudado em relação a outras áreas de Caatinga analisadas em Sergipe e no Nordeste; 2ª - não existe diferença na composição florística e estrutura fitossociológica do estrato herbáceo entre duas estações do ano (seca e chuvosa); 3ª - não existe diferença na composição florística e estrutura do estrato arbustivo-arbóreo entre borda e interior do fragmento de Caatinga estudado. Para testar a primeira hipótese foi realizada a amostragem da vegetação arbustivo-arbórea por meio de 25 parcelas, com 20x20m (400m²), distribuídas sistematicamente a intervalos de 141 m em duas direções perpendiculares entre cada parcela. Foram identificados e registrados todos os indivíduos arbustivo-arbóreos com circunferência à altura do peito (CAP a 1,30m do nível do solo) ≥ 6,0 cm e analisadas a composição florística, a estrutura fitossociológica (densidade, frequência, dominância e valor de importância), a diversidade, além da distribuição espacial e similaridade florística. A riqueza de espécies e os parâmetros estruturais do componente arbustivo-arbóreo encontrados no fragmento estudado foram superiores à maioria dos levantamentos em outras áreas do domínio Caatinga, considerando-se as diferentes tipologias analisadas (Caatinga Caducifólia Espinhosa, Caatinga Caducifólia Não Espinhosa e Vegetação Estacional Decidual). Para testar a segunda hipótese foram realizadas duas amostragens do componente herbáceo para comparação, uma na estação chuvosa e outra na seca, em 25 subparcelas, com 1x1m (1m²), distribuídas sistematicamente dentro de parcelas de 20x20m, a uma distância de 10 metros, seguindo-se a angulação de 45º a partir do primeiro vértice de cada parcela. Foram mensuradas e identificadas todas as plantas vivas com caule/pseudocaule clorofilado, com ausência ou baixo nível de lignificação que não fossem plântulas de espécies lenhosas e analisadas a composição florística, a estrutura fitossociológica (densidade, frequência, dominância e valor de importância), a diversidade, além das formas de vida de Raunkiaer. A densidade, freqüência, dominância e valor de importância das populações herbáceas, bem como, a altura e o diâmetro das plantas foram menores na estação seca. A diversidade de espécies herbáceas registrada para o fragmento foi superior a maioria dos trabalhos realizados em outras áreas de Caatinga do Nordeste brasileiro, fato que possivelmente pode estar associado ao bom estado de conservação do fragmento estudado. A forma de vida predominante da vegetação foi o terófito, seguido do fanerófito, caracterizando um fitoclima terofítico-fanerofítico para a região da área de estudo. A análise dos padrões estruturais e de diversidade realizados apenas em duas estações distintas não são suficientes para conhecer, de forma aprofundada, a dinâmica ecológica do componente herbáceo da caatinga no fragmento estudado. Para testar a terceira hipótese foram selecionadas 24 parcelas de área fixa com 20x20 metros, sendo 12 demarcadas na borda e 12 no interior do fragmento, de modo sistemático, a intervalos de 141 m. Em cada parcela foram identificados e registrados todos os indivíduos arbustivo-arbóreos com circunferência à altura do peito (CAP a 1,30m do nível do solo) ≥ 6,0 cm e mensuradas as variáveis dendrométricas para a realização dos cálculos de diversidade e estrutura, além x dessas variáveis foi calculado o índice de área foliar por meio de fotos hemisféricas com a lente olho de peixe de 180º no centro de cada parcela. Foi utilizado o escalonamento multidimensional não métrico (NMDS) para verificar a existência ou não de diferença na composição de espécies entre as parcelas da borda e do interior. Para a determinação da similaridade florística entre as parcelas avaliadas nos diferentes ambientes, foi utilizada a análise de similaridade. Diferenças entre as variáveis ambientais amostradas (variáveis dependentes) em relação à localização das parcelas de borda e interior, (variável independente) foram testadas usando modelos lineares generalizados (GLM´s). As parcelas de borda apresentaram 1157 indivíduos e 43 espécies, enquanto as do interior, 1377 indivíduos e 42 espécies. A ordenação NMDS mostrou que não existem diferenças claras na composição de espécies entre os dois ambientes analisados (borda e interior). Os cinco parâmetros estruturais da vegetação analisados entre as parcelas localizadas na borda e no interior do fragmento (altura das árvores, diâmetro do fuste, área basal, número de indivíduos e índice de área foliar) não resultaram em diferenças estatísticas significativas. Em relação aos índices referentes à riqueza, diversidade de espécies e equabilidade verificou-se, também, que não existe diferença estatística significativa entre o ambiente da borda e do interior. As semelhanças fisionômicas e estruturais da vegetação na área de estudo, evidenciadas pela riqueza, abundância e distribuição das espécies nos diferentes locais (borda e interior), sugerem a existência de um padrão comum, relacionado possivelmente com a disponibilidade de recursos de forma igualitária (como luz, água e nutrientes), histórico de conservação da vegetação do fragmento, bem como pela heterogeneidade e complexidade ambiental da área, indicando que a comunidade arbustivo-arbórea do fragmento de Caatinga não é ecologicamente afetada pela presença das bordas.
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NITERNÁ KRAJINA: SYMBOL V RANÉ POEZII VÁCLAVA RENČE OPTIKOU BREMONDOVSKÉ POESIE PURE / INTRINSICAL SCENERY: THE SYMBOL IN EARLY POETRY OF VÁCLAV RENČ VIEWED THROUGH BREMOND'S POESIE PURE THEORY

Hübnerová, Radka January 2016 (has links)
The thesis analyzes and interprets selected landscape motifs corresponding with biblical symbols in the first three collections of poetry of catholic author Václav Renč. The aim of this thesis is to give an opinion on my hypothesis that biblical symbol is a competent way of interpretation Bremond's pure poetry, and to evaluate the competence of Renč's poetry belonging to the concept of pure poetry. Also defining the limits of pure poetry through a comparison with the fourth Renč's collection which already shows significant changes in it's poetics. The theoretical part is focused on contemporary and modern literary-scientific views on Václav Renč's work, on the concept of poetry provided by Bremond, his reception in our backround and the role of the symbol in pure poetry. The thesis methodologically works with the symbol in connection with Zdeněk Mathauser's theory of a circle symbol that best corresponds with Bremond's understanding of poetry and is considered as the essential base of the theory of pure poetry. The practical part discusses the crucial landscape symbols (earth, flower and fruit, bush and tree) in single collections based on biblical interpretation and then describes their transformation in each of them. The conclusion of the confrontation with the next and at the same time the...
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Quantifying Impacts of Deer Browsing and Mitigation Efforts on Hardwood Forest Regeneration

Caleb H Redick (8067956) 03 December 2019 (has links)
<p>Due to overpopulation and resource-poor habitat structure, deer threaten the<a> future of oak and other browse-sensitive species in hardwood forests. </a>Appropriate tools must be used to ensure desirable, diverse, and ecologically stable regeneration of future forests and the sustainability of native plant communities. We performed two experiments and a review to examine the effectiveness of available methods for managing browse of hardwood seedlings and to discover how these interact with each other and other silvicultural methods. First, we examined how fencing interacts with controlled-release fertilization, seed source (genetically select and non-select), and site type (afforested and reforested sites) to enhance the regeneration of planted northern red oak (<i>Quercus rubra </i>L.), white oak (<i>Quercus alba</i>), black cherry (<i>Prunus serotina</i>), and black walnut (<i>Juglans nigra</i>) at five sites in Indiana. Fencing proved to be the greatest determinant of seedling growth, survival, and quality. Fertilizer enhanced the early growth of white oak and black cherry, though for black cherry this occurred only inside fences. Select seed sources grew better and showed greater quality; however, the survival of select seedlings was limited by deer browse in absence of fences. Trees at afforested sites had lower survival if left non-fenced. Secondly, we also investigated how fencing and invasive shrub removal affected natural regeneration, species richness, and ground-layer plant cover under closed-canopy forests. Honeysuckle (<i>Lonicera maackii</i>) removal had a variable effect depending on species and site. Positive effects were most common for shade-intolerant species, while negative effects occurred for a few shade-tolerant species at some sites. Deer fencing had a positive effect on cherry and hackberry seedling density, and a negative effect on elm seedling density. Honeysuckle and deer fencing interacted antagonistically in some instances. Fencing without honeysuckle removal resulted in lower elm abundance and herbaceous-layer cover. In the densest invasions, leaving honeysuckle intact resulted in a complete lack of recruitment into the sapling layer. Our experiment suggests that invasive shrub removal and fencing be done together. Finally, we synthesized the existing literature on browse management options for hardwood regeneration to evaluate their relative effectiveness. Fences, tree shelters, repellents, facilitation by neighboring plants, deer population control, timber harvest, and slash all had positive effects on height growth of regenerating seedlings under deer browse pressure. Fences were more effective at reducing browse than repellents, while fertilizers increased browse and had no effects on growth. </p>

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