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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.
1

Relationships among tree-species composition, vegetation structure, and forest breeding birds in southern Illinois

Edmund, Alison 01 August 2011 (has links)
Oaks (Quercus spp.) have dominated eastern forests of the United States for centuries; however, current disturbance regimes discourage oak recruitment and allow shade-tolerant mesophytic species (e.g., maples, Acer spp.) to out-compete oaks. I assessed the effects of mesophication on bird communities by examining differences in breeding bird community structure, abundance, and diversity across 8 and 12 deciduous forest stands in southern Illinois during 2009 and 2010, respectively, using line transects, and by examining a 5-year monitoring data set from across the Shawnee National Forest in 2005-2009. I predicted that variation in bird community structure between maple- and oak-dominated forests can be explained by differential availability of foraging niches. Forest stands used in 2009-2010 were separated along a gradient of hard-mast tree composition, which was defined as the percentage of tree basal area in the stand contributed by oaks and hickories (Carya spp.). Linear regression and Akaike's Information Criteria were used to assess habitat-association models for 7 bird community metrics: bird species diversity, species richness, overall abundance, and abundance of aerial foragers, bark gleaners, foliage gleaners, and ground gleaners. Bird species diversity (Shannon-Wiener H') and species richness ranged from 2.97 to 3.15, and 29 to 37, respectively, over both years. Bird species diversity and species richness were best modeled by a negative relationship with % hardmast tree basal area across both years, whereas overall abundance was best modeled by a positive relationship with understory woody stem diversity. Detection rates for foraging guilds were best modeled by various metrics of habitat structure. Aerial foragers, bark gleaners, foliage gleaners, and ground gleaners responded positively to stem density, downed coarse woody debris density, basal area, and stem diversity, respectively. I used non-metric multidimensional scaling (NMDS) and analysis of similarity (ANOSIM) to examine the degree of dissimilarity among bird communities and site type. In 2010, the bird community differed overall, with communities in oak forests tending (P = 0.09-0.11) to differ those in non-oak and mixed-mesophytic sites. Analysis of a 5-year data set yielded similar results. All models tested for bird-species diversity and species richness were competing, suggesting no individual habitat factor was a strong predictor. Overall abundance and abundance of aerial foragers, bark gleaners and foliage gleaners showed negative relationships to hardmast basal area in all years combined. Ground gleaners responded positively to tree diversity. A post-hoc analysis revealed that overall bird abundance and abundance of foliage-, bark- and ground-gleaning guilds responded positively to an index of riparian areas. Resource use during the breeding season may be shifted to mesic habitats, possibly due to increased resource availability in terms of arthropods and water. Results indicated that mesophication may not have the predicted effects on forest-breeding bird communities, and that vegetation structure was more important in determining bird community structure than tree composition in small-scale forest stands during the breeding season. Resident and over-wintering bird species may be most affected by the loss of oaks due to use during time periods when mesic habitats do not supplement resources. Managers should consider maintenance of a diversity of forest types to maximize avian diversity.
2

Caracterização genética em sementes e mudas de diferentes procedências e progênies de Mimosa scabrella Benth. do estado de Santa Catarina / Genetic characterization of seeds and seedings from different provanances and progenies of Mimosa Scabrela the State of Santa catarina

Menegatti, Renata Diane 07 July 2015 (has links)
Made available in DSpace on 2016-12-08T16:44:50Z (GMT). No. of bitstreams: 1 PGPV15MA168.pdf: 979353 bytes, checksum: 92557694bad70264bb378639576e115c (MD5) Previous issue date: 2015-07-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Mimosa scabrella Bentham, popularly known as bracatinga, is an arboreal species, native and endemic to Brazil. It is currently a prominent forest species in the south, mainly due to the high rate of growth, rapid development cycle, and presents the possibility of multiple uses of its timber production, both for wood as for more noble purposes. For the success of their large scale use is guaranteed, however, using genetic material for better performance is needed. For genetic characterization of seeds and seedlings from provenances and progenies, seeds were collected from 40 mothers, 10 in each of the four naturally occurring origins of assessed species in the state of Santa Catarina, which are: Abelardo Luz, Chapadao do Lageado , Lages and Três Barras. Biometric analysis and germination tests were carried out, from the completely randomized design, adopting four replications of 25 seeds. In the biometric evaluations, seeds were taken at random for evaluating characters: length, width and thickness. In the germination test test were evaluated: percentage of normal and abnormal seedlings, germination percentage, germination speed index, average daily germination, seedling length and dry and fresh weight of seedlings. Article I, using multivariate analysis, we determined that the characters that contributed most to the divergence between the provenances were the 42 length and width of seeds, percentage of normal seedlings, germination percentage, germination speed index and green mass of seedlings with this, it was possible to separate origins into three groups. The crossing between the origins Abelardo Luz x Lages, was one suggested as promising for future breeding programs. Article II, using univariate analysis, it was possible to evaluate the presence of significant difference between biometric characters and physiological seed quality between different arrays of Mimosa scabrella Benth, and from the Pearson correlation analysis it was concluded that the quality physiological seed has no direct relation to its size. Article III refers to the progeny test conducted at the Experimental Farm of Agroveterinárias Sciences Center at the University of the State of Santa Catarina in Lages, which was implemented with the same genetic material used in previous articles, however, in order to check genetic materials adapted to the location. The design was a randomized blocks, with forty treatments (progenies), 30 replications and ten plants per plot in single rows. At 12 months of age were evaluated for their stem diameter and total height of individuals. Significant differences were observed between provenances and progenies. The heritability coefficients at the level of individual and average of progenies, and the genetic variation coefficients were high for both traits, and the highest values were found for the origins of Abelardo Luz and Chapadao do Lageado, indicating a strong genetic control the inheritance of these characters and the possibility of finding superior individuals, which is desirable for selection with gains in future breeding programs. The genetic gains for the character stem diameter were around 57% and 49% for the character height. The results stimulate the continuity of the breeding program, with the possibility of maximizing gains in subsequent generations / Mimosa scabrella Bentham, popularmente conhecida como bracatinga, é uma espécie arbórea, nativa e endêmica do Brasil. Atualmente é uma essência florestal de destaque no Sul do país, devido, principalmente, a alta taxa de incremento, ciclo rápido de desenvolvimento, além de apresentar possibilidade de usos múltiplos de sua produção madeireira, tanto para lenha como para fins mais nobres. Para que o sucesso da sua utilização em grande escala seja garantido, porém, é necessário o uso do material genético de melhor desempenho. Para a caracterização genética das sementes e mudas provenientes de procedências e progênies, foram coletadas sementes em 40 matrizes, 10 em cada uma das quatro procedências de ocorrência natural da espécie avaliada, no estado de Santa Catarina, sendo elas: Abelardo Luz, Chapadão do Lageado, Lages e Três Barras. Foram efetuadas análises biométricas e teste de germinação de sementes, a partir do delineamento experimental inteiramente casualizado, adotando quatro repetições de 25 sementes. Nas avaliações biométricas, as sementes foram tomadas de forma aleatória para a avaliação dos caracteres: comprimento, largura e espessura. No teste de teste de germinação foram avaliados: porcentagem de plântulas normais e anormais, porcentagem de germinação, índice de velocidade de germinação, média diária de germinação, comprimento de plântulas e massa seca e verde de plântulas. No artigo I, utilizando análises multivariadas, foi possível determinar que os caracteres que mais contribuíram para a divergência entre as procedências foram o comprimento e largura de sementes, porcentagem de plântulas normais, porcentagem de germinação, índice de velocidade de germinação e massa verde de plântulas, com isto, foi possível separar as procedências em três grupos. O cruzamento entre as procedências Abelardo Luz x Lages, foi aquele sugerido como promissor para futuros programas de melhoramento genético. No artigo II, utilizando análises univariadas, foi possível avaliar a presença de diferença significativa quanto aos caracteres biométricos e de qualidade fisiológica de sementes entre as diferentes matrizes de Mimosa scabrella Benth, e a partir da análise de correlação de Pearson foi possível concluir que a qualidade fisiológica das sementes não apresenta relação direta com o seu tamanho. O artigo III refere-se ao teste de progênie conduzido na Fazenda Experimental do Centro de Ciências Agroveterinárias da Universidade do Estado de Santa Catarina, em Lages, o qual foi implantado com o mesmo material genético utilizado nos artigos anteriores, porém, visando à seleção de materiais genéticos adaptados ao local. O delineamento utilizado foi o de blocos ao acaso, com quarenta tratamentos (progênies), 30 repetições e dez plantas por parcela em linhas simples. Aos 12 meses de idade, foram avaliados os caracteres: diâmetro do coleto e altura total dos indivíduos. Diferenças significativas foram observadas entre procedências e progênies. Os coeficientes de herdabilidade em nível de indivíduo e de média de progênies, assim como os coeficientes de variação genética foram altos, para os dois caracteres avaliados, e os maiores valores foram encontrados para as procedências de Abelardo Luz e Chapadão do Lageado, indicando um forte controle genético na herança destes caracteres e possibilidade de encontrar indivíduos superiores, o que é desejável para obter ganhos com seleção em futuros programas de melhoramento genético. Os ganhos genéticos preditos obtidos para o caracter diâmetro do coleto foram entorno de 57% e 49% para o caracter altura. Os resultados estimulam a continuidade do programa de melhoramento genético, com a possibilidade de maximização dos ganhos nas gerações seguintes
3

QUALIDADE DE SEMENTES, MICROPROPAGAÇÃO, CONSERVAÇÃO IN VITRO E ISOLAMENTO DE DNA GENÔMICO DE Luehea divaricata Mart. & Zucc. / SEED QUALITY, MICROPROPAGATION, IN VITRO STORAGE AND ISOLATION OF GENOMIC DNA FROM Luehea divaricata Mart. & Zucc.

León, Enrique Asterio Benítez 27 February 2014 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Luehea divaricata Mart. & Zucc., is a native species, found in the Atlantic Forest and Pampa biomes in Rio Grande do Sul state, Brazil, belonging to the Malvaceae family. Considering the need for recovery and restoration of degraded areas, the demand for seeds and seedlings of native species may register significant increases, and the contribution of research studies to native species will be of great importance for both the forestry and the environmental sectors. This study aimed to research the quality of seeds, the development of methodologies for micropropagation and in vitro conservation of Luehea divaricata and isolation of genomic DNA of the species. Physiological and sanitary quality tests of seeds stored in Kraft paper inside refrigerator, in two different periods, collected from different places of its natural habitat, were conducted. The development of methodologies for micropropagation studies were divided in different experiments, testing at first, the response of cultures initiated from epicotyl, to stimuli from different sources and concentrations of cytokinin on in vitro multiplication. Afterwards, the pulse effect treatment with concentrations of IBA on the rooting ability of in vitro nodal segments cultivated in nutrient medium MS or WPM were tested both presence or absence of activated charcoal. For acclimatization of micropropagated plants, the effect of different concentrations of sucrose in the nutrient medium WPM and two kinds of commercial substrates were evaluated. The effect of the, osmotic regulator, mannitol, presence or absence sucrose, on the performance of in vitro nodal segments, aimed at in vitro conservation of germplasm was also observed. Three protocols were tested to isolate genomic DNA from young leaves, proving its efficiency and quality by spectrophotometry quantification and digestion with the Hind III restriction endonuclease. The main results show that genotypes differ both in their physiological and sanitary quality, and maintain their viability after six months of storage in a refrigerator. For in vitro multiplication of nodal segments, the addition of cytokinins to the nutrient medium is dispensable ,and when added, promote callus formation, unwanted at such stage. The rooting of nodal segments is successful in nutrient medium WPM in the absence of activated charcoal and it was found that the pulse treatment with IBA concentrations exceeding 9μM may optimize the process. The concentration of 30 g L-1 sucrose in the nutrient medium WPM is effective in develop plants capable of acclimatization using either commercial substrate Mecplant® or H-Decker®. It is possible in vitro conservation of nodal segments under minimal growth for a period of 120 days with the use of mannitol combined with sucrose concentrations of up to 15 g L-1 in the nutrient medium ½MS. The DNA isolated protocols were effective to obtain DNA concentration and quality still with the presence of proteins and polysaccharides. The results may contribute to the existing information on the in vitro propagation of Luehea divaricata, supporting breeding programs, germplasm conservation and analysis of genetic variability in natural populations. / Luehea divaricata Mart. & Zucc., é uma espécie nativa, dos Biomas Mata Atlântica e Pampa, pertence à família Malvaceae, conhecida comumente como açoita-cavalo. Considerando-se a necessidade de recuperação e restauração de áreas degradadas, a demanda crescente por sementes e mudas de espécies florestais nativas, e a contribuição de trabalhos de pesquisa com espécies nativas será de grande importância para o setor florestal e ambiental, o presente trabalho objetivou avaliar a qualidade de sementes, analisar e selecionar metodologias para a micropropagação e para a conservação in vitro de Luehea divaricata e, também, para o isolamento de DNA genômico da espécie. Foram conduzidos testes de qualidade fisiológica e sanitária de sementes conservadas em papel Kraft no interior de refrigerador, em dois períodos distintos, coletadas em diferentes pontos de ocorrência natural da espécie. No desenvolvimento de metodologias para micropropagação os estudos foram divididos em diferentes experimentos, testando-se, primeiramente, as respostas de culturas iniciadas a partir de epicótilos, aos estímulos de diferentes fontes e concentrações de citocinina na multiplicação in vitro. Na sequência, foi avaliado o efeito do tratamento pulse com concentrações de AIB sobre a capacidade de enraizamento in vitro de segmentos nodais, cultivados em meios nutritivos MS ou WPM, na presença ou ausência de carvão ativado. Na fase de aclimatização de plantas micropropagadas foram avaliados o efeito de diferentes concentrações de sacarose no meio nutritivo WPM, e, também, de dois tipos de substratos comerciais. Foi verificado adicionalmente, o efeito do regulador osmótico manitol, associado ou não à sacarose, sobre o desempenho in vitro de segmentos nodais, visando à conservação in vitro de germoplasma. Foram testados três protocolos para isolar DNA genômico a partir de folhas jovens, comprovou-se sua qualidade e eficiência, por meio de quantificação por espectrofotometria e digestão com a endonuclease de restrição Hind III. Os principais resultados obtidos demostraram que sementes de açoita-cavalo apresentam diferenças na sua qualidade fisiológica e sanitária, e mantêm a sua viabilidade após seis meses de armazenamento em refrigerador. Para a multiplicação in vitro de segmentos nodais de açoita-cavalo a adição de citocininas ao meio nutritivo e dispensável, e quando adicionadas, promovem formação de calos, indesejados nessa fase. O enraizamento in vitro de segmentos nodais é bem-sucedido em meio nutritivo WPM na ausência de carvão ativado e obteve-se que o tratamento pulse com concentrações de AIB superiores a 9μM pode otimizar o processo. A concentração 30 g L-1 de sacarose no meio nutritivo WPM é eficiente na formação de plantas passíveis de aclimatização utilizando-se substrato comercial Mecplant® ou H-Decker®. É possível a conservação in vitro de segmentos nodais de açoita-cavalo, sob condições de crescimento mínimo, pelo período de 120 dias com a utilização de manitol combinado a concentrações de sacarose de até 15 g L-1, no meio nutritivo ½MS. Os protocolos de isolamento de DNA são eficientes em obter DNA com quantidade e qualidade aceitáveis, porém, ainda com a presença de proteínas e polissacarídeos. Os resultados obtidos poderão contribuir com as informações existentes sobre a propagação in vitro de açoita-cavalo, apoiando programas de melhoramento, conservação de germoplasma e análise da variabilidade genética de populações naturais.
4

Evaluating Population-Habitat Relationships of Forest Breeding Birds at Multiple Spatial and Temporal Scales Using Forest Inventory and Analysis Data

Fearer, Todd Matthew 26 October 2006 (has links)
Multiple studies have documented declines of forest breeding birds in the eastern United States, but the temporal and spatial scales of most studies limit inference regarding large scale bird-habitat trends. A potential solution to this challenge is integrating existing long-term datasets such as the U.S. Forest Service Forest Inventory and Analysis (FIA) program and U.S. Geological Survey Breeding Bird Survey (BBS) that span large geographic regions. The purposes of this study were to determine if FIA metrics can be related to BBS population indices at multiple spatial and temporal scales and to develop predictive models from these relationships that identify forest conditions favorable to forest songbirds. I accumulated annual route-level BBS data for 4 species guilds (canopy nesting, ground and shrub nesting, cavity nesting, early successional), each containing a minimum of five bird species, from 1966-2004. I developed 41 forest variables describing forest structure at the county level using FIA data from for the 2000 inventory cycle within 5 physiographic regions in 14 states (AL, GA, IL, IN, KY, MD, NC, NY, OH, PA, SC, TN, VA, and WV). I examine spatial relationships between the BBS and FIA data at 3 hierarchical scales: 1) individual BBS routes, 2) FIA units, and 3) and physiographic sections. At the BBS route scale, I buffered each BBS route with a 100m, 1km, and 10km buffer, intersected these buffers with the county boundaries, and developed a weighted average for each forest variable within each buffer, with the weight being a function of the percent of area each county had within a given buffer. I calculated 28 variables describing landscape structure from 1992 NLCD imagery using Fragstats within each buffer size. I developed predictive models relating spatial variations in bird occupancy and abundance to changes in forest and landscape structure using logistic regression and classification and regression trees (CART). Models were developed for each of the 3 buffer sizes, and I pooled the variables selected for the individual models and used them to develop multiscale models with the BBS route still serving as the sample unit. At the FIA unit and physiographic section scales I calculated average abundance/route for each bird species within each FIA unit and physiographic section and extrapolated the plot-level FIA variables to the FIA unit and physiographic section levels. Landscape variables were recalculated within each unit and section using NCLD imagery resampled to a 400 m pixel size. I used regression trees (FIA unit scale) and general linear models (GLM, physiographic section scale) to relate spatial variations in bird abundance to the forest and landscape variables. I examined temporal relationships between the BBS and FIA data between 1966 and 2000. I developed 13 forest variables from statistical summary reports for 4 FIA inventory cycles (1965, 1975, 1989, and 2000) within NY, PA, MD, and WV. I used linear interpolation to estimate annual values of each FIA variable between successive inventory cycles and GLMs to relate annual variations in bird abundance to the forest variables. At the BBS route scale, the CART models accounted for > 50% of the variation in bird presence-absence and abundance. The logistic regression models had sensitivity and specificity rates > 0.50. By incorporating the variables selected for the models developed within each buffer (100m, 1km, and 10km) around the BBS routes into a multiscale model, I was able to further improve the performance of many of the models and gain additional insight regarding the contribution of multiscale influences on bird-habitat relationships. The majority of the best CART models tended to be the multiscale models, and many of the multiscale logistic models had greater sensitivity and specificity than their single-scale counter parts. The relatively fine resolution and extensive coverage of the BBS, FIA, and NLCD datasets coupled with the overlapping multiscale approach of these analyses allowed me to incorporate levels of variation in both habitat and bird occurrence and abundance into my models that likely represented a more comprehensive range of ecological variability in the bird-habitat relationships relative to studies conducted at smaller scales and/or using data at coarser resolutions. At the FIA unit and physiographic section scales, the regression trees accounted for an average of 54.1% of the variability in bird abundance among FIA units, and the GLMs accounted for an average of 66.3% of the variability among physiographic sections. However, increasing the observational and analytical scale to the FIA unit and physiographic section decreased the measurement resolution of the bird abundance and landscape variables. This limits the applicability and interpretive strength of the models developed at these scales, but they may serve as indices to those habitat components exerting the greatest influences on bird abundance at these broader scales. The GLMs relating average annual bird abundance to annual estimates of forest variables developed using statistical report data from the 1965, 1975, 1989, and 2000 FIA inventories explained an average of 62.0% of the variability in annual bird abundance estimates. However, these relationships were a function of both the general habitat characteristics and the trends in bird abundance specific to the 4-state region (MD, NY, PA, and WV) used for these analyses and may not be applicable to other states or regions. The small suite of variables available from the FIA statistical reports and multicollinearity among all forest variables further limited the applicability of these models. As with those developed at the FIA unit and physiographic sections scales, these models may serve as general indices to the habitat components exerting the greatest influences on bird abundance trends through time at regional scales. These results demonstrate that forest variables developed from the FIA, in conjunction with landscape variables, can explain variations in occupancy and abundance estimated from BBS data for forest bird species with a variety of habitat requirements across spatial and temporal scales. / Ph. D.

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