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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.
41

The roles of exotic and native tree species in preventing desertification and enhancing degraded land restoration in the north east of Libya : reciprocal effects of environmental factors and plantation forestry on each other, assessed by observations on growth and reproductive success of relevant tree species, and environmental factors analysed using multivariate statistics

Zatout, Masoud Moustafa Mohamed January 2011 (has links)
Today's arid and semi-arid zones of the Mediterranean are affected by desertification, resulting from various factors, including climatic variations and human activities such as overcultivation, overgrazing and deforestation. Afforestation programs are one of the most effective means in preventing desertification. For many years Libya has had afforestation programs in order to restore degraded land and in response to rapid desert encroachment in the north east of Libya, in the area called the Jabal Akhdar (Green Mountain), which has been investigated in this study. The purpose of this research was to investigate the relative roles of exotic compared to native tree species in preventing desertification and enhancing degraded land restoration in the Jabal Akhdar. The effect of environmental factors on exotic compared to native tree species have been assessed by observations on growth and reproductive success of the species, including variables of stocking rate, trunk diameter, tree height, crown diameter, tree coverage, natural mortality, felling and seedling regeneration, as well as calculated variables, derived from these measurements. The effects of methods and age of afforestation on the promotion of biological diversity have been investigated using the Shannon-Wiener diversity index. The effects of tree species on soil depth have also been investigated. Multivariate statistical analyses of site, species and environmental data, using both cluster analyses and factor analyses have been performed, with the aim of determining what is influencing the species, crops or differentiating between the sites, based on soil depth, angle of slope, altitude, rainfall and air temperature values. Pinus halepensis showed success in its growth and regeneration, particularly at higher altitudes and steeper slopes. Cupressus sempervirens was successful in growth and regeneration in the mountains. The exotic Eucalyptus gomphocephala was very successful in its growth, but did not regenerate well, while the exotic Acacia cyanophylla trees had a failure of both growth and regeneration. E. gomphocephala species appeared to favour relativley the flatter (non-mountain) sites, while A. Cyanophylla appeared to favour relativly the mountain sites. All the species responded positively to greater rainfall and deep soil, but they differed in where they were most likely to be successful. Environmental factors such as climate, terrain and soil are the main determinants of species distribution in the study area, in addition to their impact on the growth of the main trees. There appeared not to be any relationship between biodiversity and whether the main trees were native or exotic, and only P. halepensis showed any negative effect on the abundance of shrubs. There was greater diversity of trees and shrubs generally at the younger sites than the old sites. The present study emphasises the current mismanagement of planted forests, particularly with overgrazing contributing to desertification, through preventing tree growth and eliminating most sapling regeneration. This study concludes by making recommendations for more effective choice of tree species to plant, and for subsequent management to improve afforestation programmes in the Jabal Akhdar area.
42

Potencial de espécies nativas para a produção de madeira serrada em plantios de restauração florestal / Potential of natives species to produce timber in forest restoration plantings

Silva, Carina Camargo 15 July 2013 (has links)
Existe hoje uma crescente demanda global por ações de restauração de florestas tropicais e um dos principais entraves para a sua concretização é a viabilidade econômica dos projetos. Em cenários em que a restauração ecológica exige a implantação de reflorestamentos de espécies nativas, a produção de madeira torna-se uma alternativa importante para viabilizar economicamente a atividade, tornando-se um meio para atingir o objetivo final da restauração do ecossistema. A carência de conhecimentos técnico-científicos sobre o potencial de produção das espécies nativas em reflorestamentos é, no entanto, um entrave significativo para a sua aplicação em larga escala. Nesse contexto, o presente trabalho teve como objetivo a avaliação do potencial de espécies nativas para a produção de madeira serrada em plantios de restauração florestal. Para isso, avaliou-se o crescimento de 16 espécies nativas com potencial para produção de madeira serrada em 13 reflorestamentos mistos, com idades entre 6 e 96 anos, localizados no domínio da Floresta Estacional Semidecidual no interior do estado de São Paulo. Essas espécies foram avaliadas quanto ao crescimento em diâmetro real, diâmetro potencial, altura total e altura comercial através da modelagem destes parâmetros por técnicas de regressão linear múltipla. Tais modelos foram gerados a partir da correlação existente entre a idade do reflorestamento, o fator ambiental mais influente (relacionado ao solo e clima) e o parâmetro analisado, obtendo-se as perspectivas de desenvolvimento de cada espécie em cenários de baixa, moderada e alta produtividade de sítio. Foram estimadas as projeções do crescimento diamétrico considerando-se todos os indivíduos de cada espécie amostrados nos reflorestamentos, bem como a partir dos 25% melhores indivíduos, visando-se estimar o potencial de crescimento das espécies em condições mais favoráveis de manejo silvicultural. Foi realizada uma análise descritiva das variáveis qualitativas avaliadas em campo (número de fustes, qualidade da árvore e nível de exposição à luz), associadas às alturas total e comercial, verificando-se se as relações existentes entre estes parâmetros são capazes de orientar propostas de manejo silvicultural adequado para as espécies. Várias das espécies nativas estudadas, principalmente Cariniana legalis e C. estrellensis, apresentaram potencial satisfatório de produção de madeira serrada em plantios de restauração florestal, principalmente em condições ambientais favoráveis e se submetidas a manejo silvicultural adequado. No entanto, mesmo sob condições favoráveis, algumas espécies apresentaram crescimento excessivamente lento, desestimulando seu plantio para a produção de madeira. O ciclo de produção de madeira esperado para cada espécie foi muito variável em função das condições ambientais da área em restauração, reforçando a importância de escolha orientada de espécies para cada condição de sítio, do preparo adequado do solo e da consideração dessas condições ambientais para definir os modelos de restauração para fins de exploração de madeira. Da mesma forma, a maior parte dos indivíduos encontrava-se dominada na estrutura da floresta, reforçando a importância do espaçamento, da composição de espécies na vizinhança e de desbastes no potencial de produção de madeira. / There is a growing demand today for tropical forest restoration efforts, and one of the main barriers for accomplishing this demand is the economic viability of the projects. In scenarios where ecological restoration requires the implementation of native species plantings, the exploitation of timber can be an important alternative to make restoration financially viable, as a way to achieve the ultimate goal of the restoration of the ecosystem. The lack of technical and scientific knowledge about the potential of timber production by native species in reforestation is, however, an important obstacle for applying this alternative at the large scale. In this context, we evaluated the growth of 16 native species with potential for timber production in 13 restoration plantings, with ages ranging between 6 and 96 years, located at the Seasonal Semideciduous Forest of inland São Paulo State, southeastern Brazil. These species were evaluated regarding their growth in real and potential diameter, as well their total and commercial height, by modeling these parameters through multiple linear regressions. These models were generated based on the correlation among the age of the restoration planting, the most influent environmental factor (related to climate and soil) and the analyzed parameters, allowing us to obtaining the perspectives of growth for each species in scenarios of low, moderate and high site productivity. We established projections of growth in diameter considering all individuals sampled for each species in the reforestations, as well as the best 25% individuals, as means of estimating the potential growth of each species in more favorable scenarios of silvicultural management. We carried out a descriptive analysis of the qualitiative variables evaluated in the field (number of boles, quality of the tree and exposition to sun light), which were associated to the total and commercial heights, to verify if the relationship between these parameters may guide proposals of suitable silvicultural management for these species. Many of the studied species, especially Cariniana legalis and C. estrellensis, showed a satisfactory potential of timber production in restoration plantings, mainly in more favorable site conditions and under adequate silvicultural treatments, However, even under favorable conditions, some species presented growth rates excessively slow, which discourage their planting for timber production. The expected cycle of timber production for each species was highly variable according to the environmental characteristics of the site, thus reinforcing the importance to guide the selection of species for each site condition, to accomplish a suitable soil preparation before planting and to consider these site conditions for designing models of restoration for timber exploitation. In addition, most trees were dominated in the forest structure, which reinforces the importance of spacing, species composition of the vicinity and thinning in the potential of timber production.
43

Composição florística, estrutura e quantificação do estoque de carbono em florestas restauradas com idades diferentes / Floristic composition, structure and quantification of carbon stocks in restored forests of different ages

Preiskorn, Gabriele Marina 26 July 2011 (has links)
A crescente conscientização da importância dos serviços ambientais que as florestas proporcionam tem gerado cada vez mais esforços para a restauração desses ecossistemas. Com o objetivo de avaliar a estrutura de florestas restauradas, foram realizados levantamentos fitossociologicos, e estimados os valores de biomassa acima do solo (BAS) e estoque de carbono em quatro reflorestamentos mistos com idades de oito, 23, 55 e 94 anos. As áreas estão localizadas no Estado de São Paulo, sudeste do Brasil, nos municípios de Santa Bárbara d´Oeste (BAN), Iracemápolis (IR), Cosmópolis (COS) e Rio Claro (RC). Nas áreas foram instaladas parcelas permanentes de forma sistemática (300 m2 e 360m2) para a medição de todos os indivíduos arbóreos com diâmetro à altura do peito maior ou igual a cinco centímetros (DAP5cm). Como resultado, observou-se que a densidade dos indivíduos (ind.ha-1) e a área basal (m2.ha-1) aumentaram conforme aumenta a idade dos reflorestamentos. Fabaceae, Malvaceae e Rutaceae foram as famílias com maior riqueza de espécies comuns nas quatro áreas, semelhante às Florestas Estacionais Semideciduais (FES) naturais no Estado de São Paulo. A riqueza e a diversidade de espécies nos reflorestamentos estudados foram superiores à maioria das áreas restauradas no Estado e semelhante às FES naturais. Apesar das quatro áreas de estudo terem predomínio de espécies nativas regionais com síndrome de dispersão zoocórica, também foram encontradas espécies nativas (não regionais), exóticas, e exóticas invasoras. Entre as espécies com maior IVI (índice de valor de importância) destacaram-se Inga vera, Albizia lebbeck, Mimosa bimucronata (BAN), Melia azedarach, Leucaena leucocephala, Nectandra megapotamica (IR), Tipuana tipu, Cariniana estrellensis, Trichilia claussenii (COS), Erythroxylum pulchrum, Anadenanthera colubrina, Joannesia princeps (RC). Não houve similaridade florística entre os quatro reflorestamentos, o que era esperado visto que os reflorestamentos possuem idades e foram implantados com modelos de restauração diferentes. A presença de espécies colonizadoras (não-plantadas) no estrato regenerante pode indicar que em IR, COS e RC os processos ecológicos como a dispersão de sementes podem estar se estabelecendo. A média de BAS, estimada com a utilização de duas equações alométricas da literatura, e do estoque de carbono aumentaram conforme idade do plantio, o que foi esperado, pois as equações alométricas utilizadas neste estudo são em função do diâmetro das árvores (DAP). O estoque de carbono nos quatro reflorestamentos variou de 39,56 a 166,55 MgC.ha-1 (equação 1) e 34,43 a 104,05 MgC.ha-1 (equação 2), médias compatíveis com algumas florestas naturais de FES. As taxas de incremento médio anual em biomassa e carbono diminuíram do plantio mais jovem para o mais antigo, que sugere que os reflorestamentos mais recentes podem ser mais eficazes no sequestro de carbono atmosférico. As espécies nativas regionais e pioneiras apresentaram maiores valores de estoque de carbono nas quatro áreas estudadas. A diferença nos resultados entre as duas equações utilizadas para estimativa de BAS e estoque de carbono foi significativa, no entanto sugere-se que a escolha pela equação mais adequada leve em consideração os intervalos de diâmetro para as quais a equação foi ajustada. / The recognition of environmental services provided by forests has increased demands for ecosystem restoration. The aim of this study was to evaluate the structure of reforested areas, by collecting data on phytosociology, as well as assessment of aboveground biomass and carbon stocks of four mixed reforested areas with eight, 23, 55 and 94 years-old. The study areas were located in the State of São Paulo, southeastern Brazil, within the municipalities of Santa Barbara d´Oeste (BAN), Iracemapolis (IR), Cosmopolis (COS) and Rio Claro (RC). Permanent monitoring plots were placed systematically in each area (300 m2 and 360m2) for sampling all individual trees with diameter at breast height 5cm. The density of individuals (ind.ha-1) and the basal area (m2.ha-1) increased with age of reforested areas. The tree families Fabaceae, Malvaceae and Rutaceae presented the highest species richness of the four study areas, which was similar to other semi deciduous forests of São Paulo state. Species richness and diversity in the study areas were higher than the values obtained for other reforested areas in São Paulo state, but similar to native forests of the region. The regional native species with zoochoric syndrome dispersal were predominant in the four study areas. However, exotic species (including invasive species) were also present. The species with higher values of importance were Inga vera, Albizia lebbeck, Mimosa bimucronata (BAN), Melia azedarach, Leucaena leucocephala, Nectandra megapotamica (IR), Tipuana tipu, Cariniana estrellensis, Trichilia claussenii (COS), Erythroxylum pulchrum, Anadenanthera colubrina, Joannesia princeps (RC). There was no floristic similarity among the four study areas, and this result was expected because the study areas have different ages, as well as different models of reforestation. The presence of regenerants that colonized the areas of IR, COS and RC may indicate that ecological processes such as seed dispersal may have been established. The mean of aboveground biomass, assessed through two allometric equations obtained from the literature, and carbon stocks increased with age of reforested areas. This result was expected because the allometric equations used in this study were originally designed for trees with specific diameter intervals. The carbon stocks in the study areas varied between 39,56 and 166,55 MgC.ha-1 (equation 1) and 34,43 to 104,05 MgC.ha- 1 (equation 2), which are similar to the results obtained for some natural semi deciduous forests. The rates of biomass and carbon annual increment decreased with age of reforestation, suggesting that recent reforested areas may be more effective on carbon sequestration than older reforested areas. The native pioneer species presented high value of carbon storage in the four study areas. Because the difference in these results by using both allometric equations was statistically significant, it is suggested to select the more suitable equation by taking into account the diameter intervals originally used to adjust the equation.
44

Curva de embebição, anatomia e mobilização de reservas em sementes de Mimosa flocculosa Burkart submetidas a superação de dormência / Curve of imbibition, anatomy and mobilization of reserves in seeds of Mimosa flocculosa Burkart submmitted to overcoming of dormancy

Ribeiro, Maiara Iadwizak 08 February 2019 (has links)
Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2019-03-12T18:37:50Z No. of bitstreams: 2 Maiara_Ribeiro_2019.pdf: 660113 bytes, checksum: 19e497ad42e6f3ecf76b4cc1808ef493 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2019-03-12T18:37:50Z (GMT). No. of bitstreams: 2 Maiara_Ribeiro_2019.pdf: 660113 bytes, checksum: 19e497ad42e6f3ecf76b4cc1808ef493 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2019-02-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Our study aimed to expand the knowledge in Mimosa flocculosa seed physiology and overcome dormancy treatments efficiency, focusing on water uptake, reserves mobilization, integument anatomy and seed germination. For the hydration curve, we tested three different treatments: distilled water (control), water at 80 °C for 10 min and sulfuric acid for 3 min, each containing four replicates of 100 seeds. Seeds were placed in Germitest papers, moistened with distilled water and stored in germination chambers. To obtain fresh mass, seeds were weighted in a precision scale. From the hydration curve data, we stipulated 5 points to collect material for reserves mobilization quantification: beginning of hydration, middle of phase I, phase II, middle of phase II and beginning of phase III. Total soluble sugars, reducing sugars, sucrose, albumines, globulines, prolamines, and glutelines were quantified. The beginning of each phase was used to observe the alterations in M. floculosa integumentary seed anatomy. Germination tests were prepared in parallel with the hydration curve, in which were analyzed: germination percentage, relative frequency and synchrony of germination. We noticed that, comparing with the control, overcome dormancy treatments are indicated to improve seed germination, since germination was more uniform, sugars and proteins were more reduced during hydration, integument presented fissures and destabilization, ensuring water uptake, improving seed germination and synchrony. / O objetivo deste trabalho foi ampliar o conhecimento sobre a fisiologia da germinação das sementes de Mimosa flocculosa e a eficiência dos tratamentos de superação de dormência, tendo em foco a embebição, mobilização de reservas, a anatomia do tegumento e a germinação das sementes. Para obtenção da curva de embebição utilizamos três tratamentos testemunha, água a 80 °C durante 10 minutos e ácido sulfúrico por 3 minutos cada um com 4 repetições de 100 sementes, sendo elas dispostas em Germitest, umedecidas com água destilada e acondicionadas em câmara de germinação, para cada pesagem foi utilizada uma balança de precisão para obtenção da massa úmida. Com os dados obtidos da curva, foi estipulado os períodos de: início da embebição, meio da fase I, fase II, meio da fase II e início da fase III sendo esses, utilizados para a coleta do material para a mobilização de reservas onde foram analisadas a degradação e alterações de açúcares solúveis totais, açúcares redutores, sacarose, albuminas, globulinas, prolaminas e glutelinas. E o início de cada fase da curva, foi utilizado para observarmos as alterações na anatomia tegumentar das sementes de M. flocculosa, o teste de germinação foi instalado paralelamente a curva de embebição onde analisamos as variáveis porcentagem, frequência relativa e sincronização da germinação. Observamos, comparando com a testemunha, que, os tratamentos de superação de dormência utilizados nas sementes de M. flocculosa são indicados por elevar a germinação, pois obtiveram uma curva de embebição mais uniforme, os açúcares em conjunto com as proteínas tiveram uma redução durante os períodos da embebição mais elevada, o tegumento destes tratamentos apresentou fissuras e desestruturações auxiliando na entrada de água, elevando a germinação e com a tendência a sincronização.
45

Tundra vegetation recovery on 30 year-old seeded and unseeded drilling mud sumps in the Mackenzie River Delta region, NWT

Wunderlich, Nicole Bettina 08 April 2010
Oil and gas exploration conducted in the 1970s left behind a legacy of abandoned well sites in the Mackenzie Delta region of northern Canada, including several in the Kendall Island Migratory Bird Sanctuary and surrounding areas. Evidence of 30 year-old well sites is present in the form of drilling mud sumps, which are mounds of disturbed tundra that contain frozen drilling-wastes. One to two years after the wells were decommissioned some of the sites were seeded with non-native grass species and fertilized to test whether these treatments could accelerate vegetation recovery and prevent erosion. The main objective of this research was to examine the long-term impact of post-disturbance seeding treatments on the vegetation recovery of drilling mud sumps.<p> Surveys of vegetation composition and environmental conditions at 12 sump sites (6 seeded and 6 unseeded) showed that, after over 30 years of recovery, seeded sumps in the Mackenzie Delta did not significantly differ from those left for natural recovery. However, seeded and previously introduced grasses <i>Festuca rubra</i> and <i>Poa pratensis</i> were found on both seeded and unseeded sumps. The undisturbed surrounding tundra seems to be resistant to invasion by these introduced grasses. However, these species could become invasive in the future, particularly in the context of warming in the North and increasing anthropogenic disturbance. The results of this study contribute valuable information on the long-term effects of revegetation treatments that is critical for making informed management decisions about the rehabilitation of industrial disturbances in the Arctic.
46

Tundra vegetation recovery on 30 year-old seeded and unseeded drilling mud sumps in the Mackenzie River Delta region, NWT

Wunderlich, Nicole Bettina 08 April 2010 (has links)
Oil and gas exploration conducted in the 1970s left behind a legacy of abandoned well sites in the Mackenzie Delta region of northern Canada, including several in the Kendall Island Migratory Bird Sanctuary and surrounding areas. Evidence of 30 year-old well sites is present in the form of drilling mud sumps, which are mounds of disturbed tundra that contain frozen drilling-wastes. One to two years after the wells were decommissioned some of the sites were seeded with non-native grass species and fertilized to test whether these treatments could accelerate vegetation recovery and prevent erosion. The main objective of this research was to examine the long-term impact of post-disturbance seeding treatments on the vegetation recovery of drilling mud sumps.<p> Surveys of vegetation composition and environmental conditions at 12 sump sites (6 seeded and 6 unseeded) showed that, after over 30 years of recovery, seeded sumps in the Mackenzie Delta did not significantly differ from those left for natural recovery. However, seeded and previously introduced grasses <i>Festuca rubra</i> and <i>Poa pratensis</i> were found on both seeded and unseeded sumps. The undisturbed surrounding tundra seems to be resistant to invasion by these introduced grasses. However, these species could become invasive in the future, particularly in the context of warming in the North and increasing anthropogenic disturbance. The results of this study contribute valuable information on the long-term effects of revegetation treatments that is critical for making informed management decisions about the rehabilitation of industrial disturbances in the Arctic.
47

Comparing the effects of the exotic cactus-feeding moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) and a native cactus-feeding moth, Melitara prodenialis (Walker) (Lepidoptera: Pyralidae) on two species of Florida Opuntia

Baker, Amanda J 01 June 2006 (has links)
Exotic species are a great concern because of the possibility of negative effects once they become established. The exotic cactus moth, Cactoblastis cactorum has a reputation for being detrimental to Opuntia populations throughout Florida and the southeastern United States. Multiple projects are currently underway to attempt to contain and eradicate this species before it can migrate to the Opuntia-rich desert southwest and the agricultural Opuntia fields in the Mexican highlands. These projects have been undertaken without previous studies to determine what negative effects, if any, the moth is having on the common native Opuntia species. This is understandable; since it was earlier suggested that C. cactorum was doing great harm to rare and endangered species in the Florida Keys (Stiling et al. 2004). This study looks at the effects of the native moth borer, Melitara prodenialis and the exotic invader, Cactoblastis cactorum on two common Opuntia spp. within central Flo rida. Throughout the duration of this study, the coastal plants were subjected to damage solely by C. cactorum and the inland plants by M. prodenialis. The amount of moth damage was compared between three inland and three coastal sites, as well as between plants subjected to prescribed fire and those that were not within these sites. Plant mortality was determined for both the sites and burn treatments. The number of eggsticks was also compared between inland and coastal sites and burned and unburned treatments. The results of this study show that although there is a significant difference in plant mortality between inland and coastal sites (higher mortality was shown at inland locations), there is no difference in moth damage at these sites. This suggests that the exotic moth is doing similar or less damage to the cactus than is the native moth. The number of eggsticks was also greater at coastal sites. This indicates that although the exotic moth is more prolific than the native, it is still unable to cause higher cactus mortality rates. None of the data was significant between burned and unburned treatments, indicating that prescribed fire does not have any effect, negative or positive on the Opuntia.
48

Interactions Between an Invasive Epiphytic Bryozoan and Species of Rocky Subtidal Habitats of Nova Scotia

Yorke, Alana F 28 September 2010 (has links)
In Nova Scotia subtidal habitats, the invasive bryozoan Membranipora membranacea interacts with native bryozoan Electra pilosa on kelps, which offer high space availability but are highly dynamic, and on non-kelp algae, which provide low space but high stability. Settlers and colony cover of M. membranacea at various stages critical to its population dynamics, as well as relative abundance and encounter outcomes of M. membranacea and E. pilosa, were quantified on these substrates. I also examined the effects of various factors on growth rates of E. pilosa. For M. membranacea populations, the roles of kelp and non-kelp substrates varied intra- and inter-annually, as well as spatially. Membranipora membranacea was relatively more abundant on kelps than on Fucus, likely due to large colony size, faster growth, and strong overgrowth abilities. While kelps provide spatial resources for seasonal peaks in abundance of M. membranacea, non-kelp refuges can preserve local populations in time.
49

On the floral rewards and flower-visitor assemblages of annual urban flower meadow seed mixes

Godfrey, Thomas George January 2017 (has links)
Flower seed mixes are increasingly used to enhance the biodiversity and amenity values of urban green spaces. Urban or “pictorial” flower seed mixes are often used because they are designed using cultivars and non-native species to provide more colourful and longer-lasting flower displays. Although these seed mixes are effective in providing a high density of large colourful flowers, over an extended season, their value for biodiversity, and in particular the floral rewards they provide for flower-visitors, is largely unknown. The overall aim of my thesis was to assess and improve the value of these new urban habitats as forage resources for flower-visiting insects. My approach was to quantify and compare floral reward provision and insect visitation between meadows grown from three exemplar commercial pictorial flower meadow seed mixes (called Marmalade Annual, Short Annual and Cornfield Annual). I also compared these standard commercial mixes with corresponding ‘nectar-enriched’ formulations, which were designed by increasing the proportional seed weight contribution of selected species predicted to produce high quantities of nectar within each mix. To compare floral rewards and visitation between meadows grown from these seed mixes, I set up a field experiment in Sheffield, UK, using a complete randomised block design with six replicate blocks, each with six 25 m2 plots sown with one of the six seed mix treatments. My first objective was to quantify the floral nectar and pollen rewards provided by each flowering species recorded in the meadows (on the scale of a single flower or inflorescence). My second objective was to use these data to quantify the floral rewards provided per unit area by replicate meadows of different seed mix treatments, testing whether enrichment of seed mixes is an effective method of increasing floral nectar sugar rewards. My third objective was to corroborate/correct my morphology-based flower-visitor identifications using DNA barcoding to screen for misidentifications and morphologically cryptic species. I then used these DNA barcode-based identifications to assess whether there are systematic biases in the structure of flower-visitor networks constructed using molecular taxon identifications compared to traditional morphology-based taxon identifications. My fourth objective was to quantify patterns of insect visitation to meadows, testing whether meadows of different seed mix types attract different flower-visitor assemblages. Meadow floral composition surveys revealed that contamination by unintended horticultural species was widespread across replicate seed mix treatments, with contaminants likely germinating from a seed bank laid down during a failed attempt at this experiment the previous year. Contamination particularly affected Marmalade mixes, mainly because the common contaminant species were often also components of the Short and Cornfield mixes. For example, contaminants contributed on average about a third of nectar sugar mass or pollen volume per unit area in Marmalade mix meadows. Hence, contamination fundamentally undermined the internal validity of seed mix treatments, reducing the ability to directly attribute meadow level patterns in floral rewards or flower-visitors to seed mixes. As result, examination of patterns of floral resource provision and insect visitation were more informative at a species scale. In terms of patterns of insect visitation, Centaurea cyanus received 91% of bumblebee visits, 88% of honeybee visits and 29% of hoverfly visits, whilst T. inodorum received 27% of hoverfly visits. Patterns of bumblebee and honeybee visitation indicated preferential visitation to floral units of Centaurea cyanus. Although this species produced high quantities of nectar sugar mass and pollen volume, this did not differentiate it from other Asteraceae, such as Glebionis segetum, Rudbeckia hirta and Coreopsis tinctoria, which all produced high quantities of both floral rewards. Hence, it is likely that floral traits not measured in this study, such as nectar accessibility (‘nectar-holder depth’) or concentration/volume characteristics (which can affect accessibility due to constraints imposed by feeding morphology), drove patterns of preferential visitation in bumblebees and honeybees to C. cyanus. Given that in the absence of contamination there would have been very few bumblebee or honeybee visitors to Marmalade mix meadows, aesthetically designed pictorial meadows can fail to jointly provide benefits for people and some important flower-visiting insect taxa. DNA barcoding did not change specimen identifications for most morphotaxa. However, splitting and/or lumping processes affected almost one third of morphotaxa, with lumping of morphotaxa the most common type of change. This was in part because males and females from sexually dimorphic species were often separated by morphological identification. These DNA barcode-based changes to visitor taxonomy resulted in consistent minor changes in network size and structure across replicate networks. Lumping of morphotaxa decreased taxon richness, reducing the number of unique links and interaction diversity (the effective number of links). Lumping also increased flower-visitor generality, reducing plant vulnerability and increasing overall network connectance. However, taxonomic changes had no effect on interaction evenness or network specialisation. Thus, for this well-studied fauna, DNA barcode-based flower-visitor networks were systematically biased toward fewer taxa and links, with more generalist visitors and specialist plants. Given that many tropical faunas have more species and are less described than in Britain this pattern may not be replicated in other studies. Further studies in contrasting plant-pollinator communities are required before generalisations can be made about systematic biases between networks constructed using morphological versus molecular data. Overall, meadows grown from annual pictorial flower meadow seed mixes provide abundant floral units per unit area of meadow and are a valuable alternative to traditional horticultural flower beds or amenity grasslands in high profile urban contexts. Nevertheless, care must be taken during design of seed mixes and selection of mixes for planting to ensure that species in the mix provide suitable floral resources for an array of flower-visitors, including bees. This would be aided by the integration of informative measures for candidate species of floral rewards or visitor types and visitation rates during seed mix design.
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Propaga??o de pau-terra-liso (Qualea multiflora MART.) / Propagation of pau-terra-liso (Qualea multiflora Mart.)

Nascimento, Karyn Frichis do 25 September 2015 (has links)
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No. of bitstreams: 1 karin_frichis_do_nascimento.pdf: 1481669 bytes, checksum: c542b6f2d89d5f67694bf36d33eecd30 (MD5) Previous issue date: 2015 / O trabalho teve como objetivo desenvolver procedimentos de micropropaga??o para a esp?cie pau-terra-liso (Qualea multiflora Mart.) a partir de sementes germinadas in vitro e avaliar a emerg?ncia, o crescimento inicial e a sobreviv?ncia de mudas em fun??o de diferentes substratos e ambientes, em condi??es de viveiro. No primeiro cap?tulo, as sementes de Qualea multiflora foram submetidas ? desinfesta??o com hipoclorito de s?dio em diferentes concentra??es e tempos de imers?o para a sua introdu??o in vitro. Foi avaliado o percentual de germina??o e contamina??o. Utilizando o melhor tratamento do experimento de desinfesta??o, foi instalado outro experimento para comparar as composi??es distintas de meio de cultura MS (Murashige & Skoog, 1962) e WPM (Lloyd & McCown, 1981) na germina??o de pau-terra-liso. Avaliou-se o percentual de germina??o e de pl?ntulas normais. Na fase de multiplica??o foram utilizados dois tipos de explantes (segmento nodal e segmento cotiledonar) retirados das pl?ntulas germinadas in vitro que foram inoculados em meio de cultura WPM. Este foi suplementado com BAP em concentra??es diferenciadas e ANA. A fase foi constitu?da pelo cultivo inicial e dois subcultivos. Avaliaram-se os n?meros de brota??es por explantes e a altura da maior brota??o. Constatou-se que a concentra??o de 5% de hipoclorito de s?dio durante 20 minutos de imers?o proporcionou os melhores resultados de desinfesta??o e germina??o in vitro. Observou-se que o tipo de meio de cultura e a concentra??o influenciam na germina??o e na qualidade das pl?ntulas de Qualea multiflora, logo, recomenda-se o meio WPM com 100% de sais e vitaminas para essa esp?cie. Os melhores resultados de multiplica??o foram alcan?ados utilizando o explante cotiledonar e a concentra??o de 0,6 mg L-? de BAP. No cap?tulo 2, os experimentos foram instalados em ambiente de casa de sombra e de casa de vegeta??o utilizando quatro tipos de substratos, sendo: 1) 100% substrato comercial Bioplant?, 2) 70% de vermiculita de granulometria m?dia + 30% de fibra de coco, 3) 70% de vermiculita + 30% Bioplant?, e 4) 40% de vermiculita + 30% de fibra de coco + 30% de Bioplant?. Realizaram-se avalia??es aos 60, 90, 120 e 150 dias para verificar a emerg?ncia, o crescimento em altura e di?metro e a sobreviv?ncia das mudas. No final do experimento, foram obtidos o peso da mat?ria seca da xii parte a?rea, o peso de mat?ria seca de ra?zes, o peso de mat?ria seca total e a rela??o peso de mat?ria seca da parte a?rea e peso de mat?ria seca das ra?zes. Em casa de vegeta??o a emerg?ncia de Qualea multiflora obteve os maiores percentuais com o uso do substrato VB (70% de vermiculita + 30% de Bioplant ?). N?o ocorreu diferen?a no crescimento em altura entre as mudas que estavam em casa de vegeta??o e em casa de sombra. Para o ambiente casa de sombra, n?o houve diferen?as significativas entre as caracter?sticas de mat?ria seca analisadas, em fun??o dos substratos. Com os dados de sobreviv?ncia nos dois ambientes, conclui-se que a Qualea multiflora ? de dif?cil propaga??o em condi??es de viveiro, sendo necess?rios mais estudos para a produ??o de mudas da esp?cie. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2015. / The study aimed to develop micropropagation procedures for the ?pau-terra-liso? species (Qualea multiflora Mart.) from seeds germinated in vitro and evaluate the emergency, the initial growth and survival of seedlings for different substrates and environments in arboretum conditions. In the first chapter, the Qualea multiflora seeds were subjected to disinfection with sodium hypochlorite in different concentrations and immersion times for its introduction in vitro. The percentage of germination and contamination was evaluated. Using the best treatment of disinfestation experiment, it was installed another experiment to compare the different compositions of MS (Murashige and Skoog, 1962) and WPM (Lloyd & McCown, 1981) on the ?pau-terra-liso? germination. It was evaluated the percentage of germination and normal seedlings. In the multiplication phase it was used two types of explants (nodal segments and cotyledon segment) taken from seedlings germinated in vitro which were inoculated in WPM culture. This one was supplemented with ?BAP? and ?ANA? in different concentrations. The stage was set for the initial culture and two subcultures. It was evaluated the shoot numbers per explant and the height of the larger shoot. It was found that the concentration of 5% sodium hypochlorite for 20 minutes immersion gave the best results of disinfestation and in vitro germination. It was observed that the type of culture environment and the concentration influence the germination and quality of seedlings of Qualea multiflora, so it is recommended a WPM environment with 100% salts and vitamins for this species. The best multiplication results were achieved using cotyledon explants and concentration of 0.6 mg L-? of BAP. In Chapter 2, the experiments were conducted in shade house and greenhouse environment using four types of substrates, as follows: 1) 100% commercial substrate Bioplant?, 2) 70% of average grain size of vermiculite + 30% coconut fiber, 3) 70% of vermiculite + 30% Bioplant?, and 4) 40% of vermiculite and 30% coconut fiber + 30% Bioplant?. Evaluations were performed at 60, 90, 120 and 150 days to verify the emergence, growth in height and diameter and survival of seedlings. At the end of the experiment, it was obtained the dry matter weight of the aerial part, the dry matter weight of the roots, the entire dry matter weight and the relation between the weight of dry matter of aerial part and weight xiv of dry matter of the roots. In a greenhouse, the emergency Qualea multiflora obtained the highest percentages with the use of VB substrate (70% vermiculite and 30% of Bioplant ?). There was no difference in height growth among the seedlings that were in the greenhouse and in the shade house. To the environment shade house, there were no significant differences among the characteristics of the analyzed dry matter, according to the substrates. With the survival data in both environments, it is concluded that the Qualea multiflora is difficult to spread in arboretum conditions; further research is needed for the production of seedlings of the species.

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