Spelling suggestions: "subject:"tags"" "subject:"bags""
21 |
Avaliação da decomposição de plantas C3 e C4 em rios sob diferentes condições ambientais / Evaluation of breakdown of C3 and C4 litterfall in river under different environmental conditionsAline Fernandes Figueiredo 30 September 2015 (has links)
A matéria orgânica particulada (MOP) é a principal fonte de energia em ecossistemas lóticos, podendo ser gerada dentro ou fora do ecossistema. Os processos de produção e decomposição são particularmente importantes para a ciclagem dos nutrientes no ecossistema, afetando as relações entre biodiversidade e suas funções e propriedades. No Brasil existem poucas informações sobre a dinâmica deste material orgânico nos sistemas aquáticos, apesar das grandes dimensões das bacias hidrográficas brasileiras, e da associação destas com a vegetação ripária. Sendo assim, o presente trabalho tem como objetivo a avaliação dos efeitos dos fatores reguladores da decomposição de matéria orgânica alóctone em sistemas aquáticos, bem como os padrões de retenção, acúmulo de detritos e ciclagem de nutrientes em três rios localizados em áreas distintas, sendo dois em área florestada conservada e outro localizado em área de pastagem. Os resultados obtidos contradizem as duas hipóteses iniciais na qual a espécie de gramínea C4 (B. brizantha), devido a alta relação C:N, alto teor de lignina e baixa concentração de nitrogênio, apresentaria menores taxas de decomposição quando comparada a espécie C3 (M. schottiania) e que a decomposição de ambas as espécies seria maior no rio situado na áreas de pastagem, devido a maior temperatura causada pela maior incidência de sol neste área, que estimularia a atividade microbiana e, portanto a decomposição do resíduo. A temperatura, frequentemente relatada na literatura como principal parâmetro ambiental regulador da decomposição, não se mostrou determinante no processo de decomposição, uma vez que as maiores de perda dos detritos ocorrem no rio situado na floresta, onde os menores valores de temperatura da água foram encontrados. Sendo assim, outros fatores se mostraram mais atuantes neste processo, como as características dos substratos e a concentração de nitrato dissolvido na água. Com relação à decomposição das espécies, a B. brizantha, apesar de nutricionalmente pobre, com baixa concentração inicial de nitrogênio e alta razão C:N, foi a espécie que teve maior perda de massa nos três rios analisados, devido sua baixa concentração de lignina, composto mais recalcitrante encontrado no tecido vegetal. A lignina também se mostrou determinante na dinâmica de perdas dos demais nutrientes das duas espécies, visto que este composto pode interagir com demais constituintes celulares, formando complexos que \"mascaram\" a decomposição dos compostos mais lábeis. Sendo assim, a interação entre quantidade de nutrientes e a forma na qual este estão disponíveis será de extrema importância para a definição da velocidade de decomposição dos detritos foliares no meio ambiente / The particulate organic matter (POM) is the main energy source in stream ecosystems, which may be generated inside or outside the ecosystem. The production and decomposition processes are particularly important for nutrient cycling at the ecosystem, affecting the relationships between biodiversity and its functions and properties. In Brazil, there is little information on the dynamics of organic matter in aquatic systems, besides the great dimensions of Brazilian watersheds, and its association of those with riparian vegetation. Thus, the present study aims to evaluate the effects of factors that regulate decomposition of allochthonous organic matter in aquatic systems, as well as the patterns of retention, accumulation of debris and nutrient cycling in three rivers located in different areas, two in a preserved forest area and one in a pasture area. Our results contradict the two initial hypothesis that decomposition would be slower for C4 plants (grass), due its higher C:N, higher lignin content and low nitrogen ratios, in any environment, and that decomposition rates would be faster in the pasture streams due to the higher water temperature caused by the high incidence of sun in this area, which would stimulate microbial activity, and thus the decomposition of the residue. Temperature, commonly reported in the literature as the main environmental regulator of decomposition, was not decisive in the decomposition process, since the larger losses of mass leaf occurred at the river located at the forest, where the lowest water temperature values were found. Therefore, other factors were more effective to determine the decomposition process, such as the characteristics of the substrate and the concentration of dissolved nitrate in the water. Regarding the differences at the decomposition rates of the species, B. brizantha, although nutritionally poor, with low initial nitrogen concentration and high C: N ratio, was the species with greater weight loss at the three rivers studied, due to its low lignin concentration, which is the most recalcitrant compound found in the plant tissue. Lignin also influenced the dynamic of nutrient losses of the two species, since this compound can interact with other cellular constituents, preventing the decomposition of the most labile compounds. Thus, the balance between the amount of nutrients and the form in which they are available will be extremely important to define the decomposition rate of leaf litter at the environment
|
22 |
A decomposição de detritos foliares de espécies nativas e exótica e a colonização de macroinvertebrados em um riacho tropical localizado na Floresta Nacional de Ipanema, SP, Brasil / The leaf litter decomposition in native and exotic species and the macro invertebrate colonization in a tropical river placed in the Floresta Nacional de Ipanema, SP, BrazilSuarez Robayo, Heidi Marcela 01 July 2016 (has links)
As matas riparias tem efeitos positivos sobre a qualidade da água em rios de baixa ordem. O cultivo e a substituição de plantas de espécies nativas por espécies exóticas, tem efeitos e impactos significativos na biodiversidade de ambientes aquáticos e terrestre. O cultivo de Eucalyptus ocupam áreas de importância biológica e ambiental, causando impactos que ainda são pouco estudados, interferindo no funcionamento dos cursos de água que são dependentes do material foliar disponível nas margens dos rios como fonte de energia e nutrientes. O presente trabalho comparou a decomposição de folhas de espécies nativas (Inga marginata e Matayba elaeagnoides) e folhas de uma espécie exótica (Eucalyptus grandis) durante as estações seca e chuvosa, num riacho localizado no interior da Floresta Nacional de Ipanema, unidade de conservação situada no sudeste do estado de São Paulo. Para a comparação foi utilizado o método de litter bags usando sacos de malha grossa plástica de 10 mm de abertura, por períodos de no máximo 60 dias. Neste período também foi avaliada a colonização de macroinvertebrados bentônicos em cada um dos tratamentos testados. Entre as estações (seca e chuvosa), as perdas de massa foliar foram distintas, assim também existiram diferenças entre as espécies de plantas testadas (Inga marginata, Matayba elaeagnoides e Eucalyptus grandis), sendo sempre maior a perda nas folhas de Inga marginata, seguida das folhas de Eucalyptus grandis e Matayba elaeagnoides, e obtendo os maiores valores de perda de massa na estação chuvosa. Foram identificados 801 indivíduos que colonizaram nos três tratamentos testados na época seca e 556 indivíduos que colonizaram nos tratamentos na época chuvosa, existindo uma relação entre os valores de perda de massa e a abundância de organismos macroinvertebrados para cada um dos tratamentos, sendo os tratamentos com maiores perdas os que tiveram maiores valores de organismos colonizados. Os maiores valores de perda de massa para a folha de Inga marginata foi maior em comparação dos outros tratamentos além de apresentar a maior quantidade de macroinvertebrados aquáticos colonizados nas duas épocas avaliadas. As famílias mais representativas foram: Chironomidae, Hyalellidae, Gomphidae, Calamoceratidae, Leptophlebiidae e Elmidae. Assim os grupos funcionais com maior presença foram os grupos coletor e predador, não existindo diferenças significativas na presença destes grupos. O grupo fragmentador foi o terceiro grupo mais representativo para os três tratamentos e nas duas épocas avaliadas. Nesse tipo de ambiente tropical, a comunidade de fungos e bactérias é rico e diverso, fazendo esse processo biológico, importante para a transformação das folhas em um recurso de maior facilidade de assimilação para seu aproveitamento, tornando assim as folhas mais acessíveis para os organismos invertebrados. Deste modo, por exemplo transformando as folhas de eucalipto em um recurso, sendo estas folhas também acondicionadas para o consumo dos organismos e podendo-se constituir como um recurso adicional para a biota e os organismos se adaptando para a assimilação deste recurso. A presença de folhas de eucalipto pode influenciar na colonização dos organismos invertebrados, podendo interferir no processo natural da colonização de macroinvertebrados aquáticos e alterando a disponibilidade de nutrientes dentro das teias tróficas destes sistemas aquáticos. / The crumbled vegetation has positive effects on water quality in a low river. The crop plants and replacement of native species by exotic species, has significant effects and impacts on biodiversity of aquatic and terrestrial environments. Eucalyptus cultivation occupies areas of biological and environmental importance, causing impacts that are still poorly studied, interfering with the operation of the waterways that depend on available vegetable waste on the banks of rivers as a source of energy and nutrients. This study compared the decomposition of leaves of native species (Inga marginata and Matayba elaeagnoides) and leaves of an exotic species (Eucalyptus grandis) during the dry and rainy seasons in a river located within of the Floresta Nacional de Ipanema, conservation unit located in the southeastern state of São Paulo. For the comparison, the litter bags method was used. Thus, networks of plastic coarse mesh with an opening of 10 mm maximum were used for periods of 60 days. In this period the colonization of bentic macroinvertebrates in each of the treatments was also evaluated. Between the seasons (dry and rainy), losses of plant mass were different among different species of evaluated plants (Inga marginata, Matayba elaeagnoides and Eucalyptus grandis), considering that the loss of leaves of Inga marginata was higher, followed by the Eucalyptus grandis and Matayba elaeagnoides leaves. As a result, the loss of mass in the rainy season was evident. Thus, 801 individuals that colonized the three treatments evaluated in the dry season and 556 individuals that colonized treatments in the rainy season were identified. As consequence, there is a relationship between the values of loss of plant material and abundance of macroinvertebrates organisms for each of the treatments. The treatments with higher losses those who had higher values of colonized organisms. The largest mass loss values for Inga marginata sheet was higher in comparison of other treatments as well as presenting the greatest amount of aquatic macroinvertebrates colonized in the two seasons evaluated. The most representative families were: Chironomidae, Hyalellidae, Gomphidae, Calamoceratidae, Leptophlebiidae and Elmidae. Thus, the functional groups with the largest presence were collectors and predators groups, with no significant differences in the presence of these groups, the shredder group was the third most representative group for the three treatments and two periods evaluated. In this type of tropical environment, the community of fungi and bacteria is abundant and diverse, making of this biological process, an important aspect for the transformation of leaves in a resource ease of assimilation for its use, allowing these to become more accessible for invertebrate organisms. Considering the previous information, this allowed the Eucalyptus leaves transform in a resource available for consumption of organisms and being able to be as an additional resource for biota and organisms adapting to the assimilation of this resource. Thus, the presence of Eucalyptus leaves can influence the colonization of invertebrate organisms, it may interfere with the natural process of colonization of aquatic macroinvertebrates and altering the availability of nutrients in the food chains of these aquatic ecosystems.
|
23 |
Environmental levy and green citizenship on plastic shopping bags behaviours in Hong KongWong, Wing-sum., 黃詠森. January 2012 (has links)
The Environmental Levy Scheme on Plastic Shopping was enforced in July 2009. The Levy aimed to create a direct fiscal disincentive to reduce the indiscriminate use of Plastic Shopping Bags and encourage consumers to switch to reusable shopping bags. In theory, fiscal instruments are more efficient and effective to change people’s behaviour, but its impacts towards attitude are still in question. Also, the level of green citizenship, which emphasising that people have the responsibility to protect and sustain the environment, is a good indicator to know people’s attitudes towards the environment, but the Hong Kong government tends to rely on fiscal disincentives to change people’s behaviour, Green Citizenship had never been addressed. Green citizenship is a personal commitment to learn more about the environment and to take responsible environmental action. Environmental citizenship encourages individuals, communities and organizations to think about the environmental rights and responsibilities we all have as residents of the planet Earth (Environmental Canada, 2006). This study carried out a questionnaire research to identify the policy effect that the Levy in Hong Kong have on environmental attitudes and behaviours, as well as to identify the relative impact of economic incentive versus Green Citizenship on green attitudes and behaviours. The survey was conducted from 25th April to 9th May 2012 for two weeks in the form of internet survey. The research found that the Environmental Levy Scheme on Plastic Shopping Bags affected citizens’ behaviour and attitude to reduce the use of plastic shopping bags, and also changed people’s behavioural intention to act pro-environmentally, if their beliefs are strong enough to override the disadvantages brought by pro-environmentally actions. However, the level of green citizenship in Hong Kong is still in a private level, the sense of green citizenship of the society is still weak, thus, a comprehensive education programme should be carried out by both the society (bottom-up) and the government (top-bottom) to raise the level of green citizenship of the society. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
|
24 |
A decomposição de detritos foliares de espécies nativas e exótica e a colonização de macroinvertebrados em um riacho tropical localizado na Floresta Nacional de Ipanema, SP, Brasil / The leaf litter decomposition in native and exotic species and the macro invertebrate colonization in a tropical river placed in the Floresta Nacional de Ipanema, SP, BrazilHeidi Marcela Suarez Robayo 01 July 2016 (has links)
As matas riparias tem efeitos positivos sobre a qualidade da água em rios de baixa ordem. O cultivo e a substituição de plantas de espécies nativas por espécies exóticas, tem efeitos e impactos significativos na biodiversidade de ambientes aquáticos e terrestre. O cultivo de Eucalyptus ocupam áreas de importância biológica e ambiental, causando impactos que ainda são pouco estudados, interferindo no funcionamento dos cursos de água que são dependentes do material foliar disponível nas margens dos rios como fonte de energia e nutrientes. O presente trabalho comparou a decomposição de folhas de espécies nativas (Inga marginata e Matayba elaeagnoides) e folhas de uma espécie exótica (Eucalyptus grandis) durante as estações seca e chuvosa, num riacho localizado no interior da Floresta Nacional de Ipanema, unidade de conservação situada no sudeste do estado de São Paulo. Para a comparação foi utilizado o método de litter bags usando sacos de malha grossa plástica de 10 mm de abertura, por períodos de no máximo 60 dias. Neste período também foi avaliada a colonização de macroinvertebrados bentônicos em cada um dos tratamentos testados. Entre as estações (seca e chuvosa), as perdas de massa foliar foram distintas, assim também existiram diferenças entre as espécies de plantas testadas (Inga marginata, Matayba elaeagnoides e Eucalyptus grandis), sendo sempre maior a perda nas folhas de Inga marginata, seguida das folhas de Eucalyptus grandis e Matayba elaeagnoides, e obtendo os maiores valores de perda de massa na estação chuvosa. Foram identificados 801 indivíduos que colonizaram nos três tratamentos testados na época seca e 556 indivíduos que colonizaram nos tratamentos na época chuvosa, existindo uma relação entre os valores de perda de massa e a abundância de organismos macroinvertebrados para cada um dos tratamentos, sendo os tratamentos com maiores perdas os que tiveram maiores valores de organismos colonizados. Os maiores valores de perda de massa para a folha de Inga marginata foi maior em comparação dos outros tratamentos além de apresentar a maior quantidade de macroinvertebrados aquáticos colonizados nas duas épocas avaliadas. As famílias mais representativas foram: Chironomidae, Hyalellidae, Gomphidae, Calamoceratidae, Leptophlebiidae e Elmidae. Assim os grupos funcionais com maior presença foram os grupos coletor e predador, não existindo diferenças significativas na presença destes grupos. O grupo fragmentador foi o terceiro grupo mais representativo para os três tratamentos e nas duas épocas avaliadas. Nesse tipo de ambiente tropical, a comunidade de fungos e bactérias é rico e diverso, fazendo esse processo biológico, importante para a transformação das folhas em um recurso de maior facilidade de assimilação para seu aproveitamento, tornando assim as folhas mais acessíveis para os organismos invertebrados. Deste modo, por exemplo transformando as folhas de eucalipto em um recurso, sendo estas folhas também acondicionadas para o consumo dos organismos e podendo-se constituir como um recurso adicional para a biota e os organismos se adaptando para a assimilação deste recurso. A presença de folhas de eucalipto pode influenciar na colonização dos organismos invertebrados, podendo interferir no processo natural da colonização de macroinvertebrados aquáticos e alterando a disponibilidade de nutrientes dentro das teias tróficas destes sistemas aquáticos. / The crumbled vegetation has positive effects on water quality in a low river. The crop plants and replacement of native species by exotic species, has significant effects and impacts on biodiversity of aquatic and terrestrial environments. Eucalyptus cultivation occupies areas of biological and environmental importance, causing impacts that are still poorly studied, interfering with the operation of the waterways that depend on available vegetable waste on the banks of rivers as a source of energy and nutrients. This study compared the decomposition of leaves of native species (Inga marginata and Matayba elaeagnoides) and leaves of an exotic species (Eucalyptus grandis) during the dry and rainy seasons in a river located within of the Floresta Nacional de Ipanema, conservation unit located in the southeastern state of São Paulo. For the comparison, the litter bags method was used. Thus, networks of plastic coarse mesh with an opening of 10 mm maximum were used for periods of 60 days. In this period the colonization of bentic macroinvertebrates in each of the treatments was also evaluated. Between the seasons (dry and rainy), losses of plant mass were different among different species of evaluated plants (Inga marginata, Matayba elaeagnoides and Eucalyptus grandis), considering that the loss of leaves of Inga marginata was higher, followed by the Eucalyptus grandis and Matayba elaeagnoides leaves. As a result, the loss of mass in the rainy season was evident. Thus, 801 individuals that colonized the three treatments evaluated in the dry season and 556 individuals that colonized treatments in the rainy season were identified. As consequence, there is a relationship between the values of loss of plant material and abundance of macroinvertebrates organisms for each of the treatments. The treatments with higher losses those who had higher values of colonized organisms. The largest mass loss values for Inga marginata sheet was higher in comparison of other treatments as well as presenting the greatest amount of aquatic macroinvertebrates colonized in the two seasons evaluated. The most representative families were: Chironomidae, Hyalellidae, Gomphidae, Calamoceratidae, Leptophlebiidae and Elmidae. Thus, the functional groups with the largest presence were collectors and predators groups, with no significant differences in the presence of these groups, the shredder group was the third most representative group for the three treatments and two periods evaluated. In this type of tropical environment, the community of fungi and bacteria is abundant and diverse, making of this biological process, an important aspect for the transformation of leaves in a resource ease of assimilation for its use, allowing these to become more accessible for invertebrate organisms. Considering the previous information, this allowed the Eucalyptus leaves transform in a resource available for consumption of organisms and being able to be as an additional resource for biota and organisms adapting to the assimilation of this resource. Thus, the presence of Eucalyptus leaves can influence the colonization of invertebrate organisms, it may interfere with the natural process of colonization of aquatic macroinvertebrates and altering the availability of nutrients in the food chains of these aquatic ecosystems.
|
25 |
"Fatores determinantes no processo de decomposição em florestas do Estado de São Paulo". / Determinant factors of decomposition process in São Paulo State forestsCastanho, Camila de Toledo 05 August 2005 (has links)
A atividade de decomposição constitui-se em importante indicador do padrão funcional dos ecossistemas, pois controla processos básicos relacionados à disponibilidade de nutrientes e produtividade. Salienta-se a importância das características climáticas, edáficas, da qualidade da serapilheira e da fauna do solo como determinantes no processo de decomposição. No entanto, a importância de cada um destes fatores varia em escalas de tempo e espaço. O objetivo deste trabalho foi avaliar a importância de alguns fatores determinantes na decomposição em trechos representativos dos principais ecossistemas florestais do Estado de São Paulo. Para tanto foram conduzidos dois experimentos independentes. O primeiro, aqui denominado Experimento Exóticas, examinou os efeitos do tipo florestal e da fauna do solo sobre a decomposição de folhas de uma espécie exótica (Laurus nobilis L.) em duas florestas úmidas (Floresta de Restinga do Parque Estadual da Ilha do Cardoso e Floresta Atlântica de Encosta do Parque Estadual Carlos Botelho) e uma floresta estacional (Floresta Estacional Semidecidual da Estação Ecológica de Caetetus). Os efeitos destes fatores foram testados em duas situações: acima e abaixo da superfície simulando então o ambiente de decomposição de folhas e raízes respectivamente. O tipo florestal apresenta efeito superior à fauna acima da superfície, enquanto abaixo apenas o efeito da fauna é significativo. Esses resultados indicam que a hierarquia dos fatores determinantes na decomposição difere para folhas e raízes. Se por um lado a decomposição de folhas é muito mais susceptível às mudanças climáticas do que a de raízes, por outro, alterações na comunidade afetam a decomposição em ambas as condições. Acima da superfície, a fauna apresentou efeito significativo apenas na Floresta Atlântica de Encosta, sendo essencial na diferenciação das duas florestas úmidas. Abaixo da superfície e na ausência da fauna, a porcentagem de massa remanescente foi muito similar nas três florestas. No entanto, diferenças entre as florestas, na presença da fauna, tornam-se aparentes sugerindo que há contribuição específica da fauna na decomposição de raízes destas florestas. A Floresta de Restinga apresentou o efeito mais pronunciado da fauna abaixo do solo. Esses resultados indicam que a fauna é um fator de notável importância na determinação da decomposição de raízes, particularmente em florestas tropicais úmidas arenosas. Outro experimento, aqui denominado Experimento Nativas, foi desenvolvido para avaliar o efeito do substrato e da formação florestal na decomposição de folhas de quatro espécies nativas em trechos das quatro principais formações florestais do Estado de São Paulo. Para tanto, o experimento foi desenvolvido nos três trechos florestais do experimento Exóticas incluindo ainda o Cerradão da Estação Ecológica de Assis. Foi escolhida uma espécie de árvore, em cada um dos tipos florestais, para que suas folhas fossem usadas como substrato nas bolsas de serapilheira. Tipo florestal e substrato demonstraram efeito significativo sobre a quantidade de massa remanescente ao longo do experimento. A maior parte das espécies sofreu maiores perdas na Floresta Atlântica, seguida da Floresta de Restinga, Floresta Estacional e Cerradão. Esses resultados sugerem que o total de precipitação associado a sua distribuição são importantes determinantes no processo de decomposição, de forma que as duas florestas mais úmidas apresentam, em média, taxas de decomposição duas vezes maiores do que as duas florestas estacionais. As demais diferenças encontradas entre as formações florestais devem ser explicadas por características edáficas e bióticas. Em relação ao efeito das espécies, observaram-se as maiores perda de massa em Esenbeckia leiocarpa Engl., seguida de Copaifera langsdorfii Desf., Guapira opposita Vell. e Calophyllum brasiliensis Camb.. Os parâmetros químicos só mostram correlação negativa significativa com as taxas de decomposição quando G. opposita é excluída da análise. Neste caso a porcentagem de lignina foi o parâmetro que apresentou melhor correlação (r2= 0,59). Apesar dos padrões gerais apresentados acima, a interação entre tipo florestal e substrato evidencia algumas variações, que se relacionam principalmente ao aumento relativo na perda de massa de C. langsdorfii em sua área de origem, o Cerradão. Quando comparadas as taxas de decomposição (k) encontradas na Floresta Estacional e no Cerradão, C. langsdorfii apresenta decaimento 40% maior no Cerradão, enquanto as demais espécies apresentam, em média, taxas 28% menores no Cerradão do que na Estacional. Esses resultados sugerem estreita correlação entre a comunidade decompositora e a serapilheira local. O estudo do processo de decomposição, reconhecendo seus fatores determinantes e a variação na hierarquia desses fatores em diferentes condições ambientais, como apresentado nesse trabalho, é de fundamental importância, não só para o entendimento dos ecossistemas florestais de São Paulo, mas para o planejamento de atividades de manejo, restauração e conservação. / Composition is an important indicator of functional patterns of ecosystems, as it controls basic processes related to the availability of nutrients and to ecosystem productivity. Climatic and edaphic conditions and the quality of the litter and soil fauna as determining factors are of particular importance in the process of decomposition. The significance of each one of these varies with spatial and temporal scale. The objective of this work was to evaluate the importance of certain determining factors of decomposition in sites representing the main forest ecosystems of the state of São Paulo, Brazil. To accomplish this, two independent experiments were conducted. The first, denoted here as the Exotics" experiment, was to examine the effects of the type of forest and the soil fauna on the decomposition of leaves of an exotic species (Laurus nobilis L.) in two humid forests (Restinga Forest of the Parque Estadual da Ilha do Cardoso e Atlantic Forest of the Parque Estadual Carlos Botelho) and a seasonal forest (Semideciduous Forest of the Estação Ecológica de Caetetus). The effects of these factors were tested above and belowground, to simulate the environment of decomposition among leaves and roots respectively. The type of forest had a significant effect over fauna above the surface, while below the surface, only fauna had significant effect. These results indicate that the hierarchy of determining factors in decomposition differs between leaves and roots. If on the one hand decomposition in leaves is much more susceptible to variation in climate than are roots, on the other hand changes in the soil fauna affect decomposition in both environments. Above the surface, fauna had a significant effect only in the Atlantic Forest, emphasizing the difference between two humid forests. Under the surface, and in the absence of fauna, the percentage of remaining biomass was very similar in the three forests. Notwithstanding differences in the forests, the presence of fauna was apparent, suggesting that there is a specific contribution of fauna in decomposition among roots in these forests. The Restinga Forest produced the most pronounced effect of fauna below the soil surface. These results indicate that fauna is a factor of notable importance in the decomposition of roots, especially in humid sandy tropical forests. The other experiment, here called the Native" experiment, was developed to evaluate the effects of the substrate and the forest type on the decomposition of leaves of four native species in sites of the four major forest types in São Paulo state. The experiment was conducted in the same three forest sites as the Exotics" experiment, including the Cerradão da Estação Ecológica de Assis. A tree species was chosen in each forest type, the leaves of which were used as substrate for the litter bags. The type of forest and the substrate demonstrated a significantly greater effect on the quantity of remaining mass throughout the experiment. The majority of the species suffered greater losses in the Atlantic Forest, followed by the Restinga Forest, the Semideciduous Forest, and the Cerradão. These results suggest that the total associated precipitation and its distribution are important determinants in the process of decomposition. As such, the two most humid forests show, on average, decomposition rates twice as great as the two seasonal forests. The rest of the differences encountered between forest types can be explained by edaphic and biotic factors. With respect to the effect of the species, the greatest biomass losses were observed in Esenbeckia leiocarpa Engl., followed by Copaifera langsdorfii Desf., Guapira opposita Vell. and Calophyllum brasiliensis Camb. Chemical parameters only show significant negative correlation with decomposition rates when G. opposita is excluded from the analysis. In this case the percentage of lignin was the parameter that showed the greatest correlation (r2= 0,59). In spite of the general patterns presented above, the interaction between forest type and substrate showed some variation, principally related to the loss of mass of C. langsdorfii in its native habitat, the Cerradão. Comparing decomposition rates (k) found in the Semideciduous Forest and Cerradão, C. langsdorfii shows a decrease of 40% more in the Cerradão, while the other species show, on average rates 28% lower in the Cerradão than in the Semideciduous Forest. These results suggest a strict correlation between the decomposition community and the local litter. Understanding processes of decomposition, is of fundamental importance and includes recognizing the determining factors and the variation in the importance of these factors under different environmental conditions, as presented in this study. This is true not only for our understanding of the forest ecosystems of São Paulo, but also for management planning, restoration, and conservation.
|
26 |
Digest?o Total e Parcial de Forrageiras em Equinos / Total and partial forage digestion in horsesRodrigues, Liziana Maria 29 October 2009 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-09-12T16:46:41Z
No. of bitstreams: 1
2009 - Liziana Maria Rodrigues.pdf: 560442 bytes, checksum: 3ed65532525d106ac2a5c430b0f2059b (MD5) / Made available in DSpace on 2018-09-12T16:46:41Z (GMT). No. of bitstreams: 1
2009 - Liziana Maria Rodrigues.pdf: 560442 bytes, checksum: 3ed65532525d106ac2a5c430b0f2059b (MD5)
Previous issue date: 2009-10-29 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / This study was carried out to estimate the prececal and total nutrient?s digestibility of forages by total feces collection and mobile bag techniques and evaluate the passage kinetics in the digestive tract of horses using mobile bags. This work was conducted with three assays. The first was carried out to estimate nutrient?s digestibility of coast cross hay (Cynodon dactylon cv. coastcross) with the total feces collection technique. The second assay was carried out to estimate nutrient?s digestibility of lucerne hay (Medicago sativa), coast cross hay, and peanut forage (Arachis pintoi) with the mobile bag technique. The last one was carried out to evaluate the prececal nutrient?s digestibility of the same forages used at second assay with the mobile bag technique in a horse cannulated at cecum. The two first assays were simultaneously, with four horses with average weight of 300kg fed coast cross hay only. Water and mineral salt was offered ad libitum. The nylon bags has 45? of porosity and 6.5x 3.0cm of internal dimension and were fill with 663 mg of forage samples ground at 1mm. These assays had duration of 19 days, 10 days for adaptation and regulation of intake, and the last five days to introduce the bags in the stomach and, bags collections in the feces. Two insertions of bags were made at day with 25 bags, eight bags per forage and one empty bag. The feces and the bags were kept on the floor quickly after the horses crap, the bags were separate and the time noted. The assay of prececal digestibility had duration of 20 days which the first 5 days were to horse adaptation and the last 15 days were to insert and recovery the bags in the cecum. In this assay the bags were similar of those used in the first assay, but with a little washer in the border of the bags to possibility the recovery them in the cecum with a magnet. The magnet was place into the cannula near the ileocaecal junction, and at every 30 minutes beginning one hour after bag?s insertion in the stomach, the magnet was withdraw and the bags was removed until 7 hours later. Values of total digestibility with feces collection and mobile bags were similar with the possibility to use the mobile bag technique as alternative to feces collection. There wasn?t differences between digestibility of nutrients of lucerne and peanut forage with mobile bags technique (P<0.05), nevertheless those were higher than the coast cross hay. The use of mobile bag in cannulated horses allow to estimate the digestibility from different segments of the intestine, show to be a good alternative to study the digestion in horses / Este trabalho teve como objetivo estimar a digestibilidade parcial e total dos nutrientes de forrageiras atrav?s das t?cnicas de coleta total de fezes e sacos de n?ilon m?veis e avaliar a cin?tica de passagem de sacos de n?ilon m?veis no trato digest?rio de equinos. O experimento foi dividido em tr?s ensaios. O primeiro ensaio estimou a digestibilidade dos nutrientes do feno de coastcross (Cynodon dactylon cv. coastcross) atrav?s da coleta total de fezes. O segundo ensaio estimou a digestibilidade dos nutrientes do feno de alfafa (Medicago sativa), do feno de coastcross e do amendoim forrageiro (Arachis pintoi) com a t?cnica de sacos de n?ilon m?veis. O terceiro ensaio foi realizado utilizando as mesmas forrageiras do segundo ensaio, avaliando a digestibilidade pr?-cecal com a t?cnica dos sacos de n?ilon m?veis em equino fistulado no ceco. Os dois ensaios de digest?o iniciais foram realizados simultaneamente, com quatro equinos adultos com peso m?dio de 300kg alimentados com dieta exclusiva de feno de coastcross. A ?gua e o sal mineral foram fornecidos ad libitum. Foram utilizados sacos de n?ilon com porosidade de 45? com dimens?es internas de 6,5x 3cm, e preenchidos com 663mg de amostra das forrageiras mo?das a 1mm. Os dois ensaios iniciais tiveram dura??o de 19 dias, sendo 10 dias de adapta??o e regula??o do consumo da dieta, cinco dias para inser??o g?strica dos sacos, coleta total de fezes e dos sacos de n?ilon nas fezes. Para inser??o g?strica dos sacos de n?ilon, foram feitas duas sondagens ao dia, com 25 sacos, oito com amostras de cada alimento e um em branco. As fezes e os sacos foram coletados do piso das baias imediatamente ap?s a excre??o, os sacos foram separados manualmente e anotado o tempo de tr?nsito. O ensaio de digest?o pr?-cecal teve dura??o de 20 dias sendo os cinco primeiros para adapta??o do animal ao manejo e 15 dias de sondagens e recupera??o dos sacos. Neste ensaio foram utilizados sacos semelhantes ao ensaio anterior, por?m em uma das extremidades dos sacos foi afixada uma arruela met?lica para permitir que o saco fosse recuperado no ceco com aux?lio de um im?. Este im? foi posicionado pr?ximo a jun??o ?leo-cecal e, a intervalos de 30 minutos, iniciando uma hora ap?s a inser??o dos sacos no estomago e, o im? foi retirado da c?nula e os sacos aderidos foram coletados at? 7 horas ap?s a inser??o g?strica. Os valores de digestibilidade total atrav?s da coleta de fezes e dos sacos m?veis foram semelhantes confirmando a possibilidade de utiliza??o dos sacos m?veis como alternativa a coleta de fezes. N?o houve diferen?a entre os coeficientes de digestibilidade do feno de alfafa e do amendoim forrageiro com os de sacos de n?ilon m?veis (P<0,05), no entanto estes foram maiores que o do feno de coastcross. O uso da t?cnica de sacos de n?ilon m?veis em animais fistulados permitiu estimar a digestibilidade pr?-cecal e p?s-ileal em equinos, mostrando ser uma alternativa vi?vel no estudo dos processos digestivos desta esp?cie.
|
27 |
No Plastic Bags : The Influence of Different Factors on Consumer Attitudes towards an Environmental InitiativeBovinder Ylitalo, Linnéa, Peter, Gerdin January 2009 (has links)
<p>Environmental issues have within the recent years become a frequently debated matter and corporate social responsibility (CSR) has become a new determinant for consumers purchase decisions. As a consequence of this, ever more companies have begun to implement different CSR initiatives in order to take responsibility for the environment. The arguments differ among researchers whether it is actually profitable for companies to invest in CSR initiatives.</p><p>In this study we have based upon the functional theory of attitudes and identified different factors that are likely to affect consumer attitudes towards an environmental CSR initiative and formed a model for this. The model postulates four main factors that are likely to affect consumers attitudes towards an environmental initiative; which attitude a consumer holds towards the actual product (in this case the paper bags) in question, the extent to which a consumer considers environmental responsibility to be important, the extent to which a consumer considers environmental issues to be a threat to her-/himself and the amount of information a consumer receives about the initiative. To test our model we used a quantitative approach and investigated the consumer attitudes towards the initiative <em>no plastic bags</em> at the shopping centre Strömpilen, Umeå.</p><p>We found that consumers in general are very positive towards the initiative. We then looked closer into what parts of our model that had significant impact on consumer attitudes towards the concept. The Chi-Square tests showed that three of four parts in the model could be verified. These parts were; the consumer’s attitude towards the actual product (in this case the paper bag), how important environmental responsibility is to a consumer and to what extent a consumer sees environmental issues as a threat to her-/himself. The fourth part of the model; the amount of information a consumer has received could not be verified. Thus the model was modified and was in the end constituted by the three parts that had been statistically verified.</p>
|
28 |
No Plastic Bags : The Influence of Different Factors on Consumer Attitudes towards an Environmental InitiativeBovinder Ylitalo, Linnéa, Peter, Gerdin January 2009 (has links)
Environmental issues have within the recent years become a frequently debated matter and corporate social responsibility (CSR) has become a new determinant for consumers purchase decisions. As a consequence of this, ever more companies have begun to implement different CSR initiatives in order to take responsibility for the environment. The arguments differ among researchers whether it is actually profitable for companies to invest in CSR initiatives. In this study we have based upon the functional theory of attitudes and identified different factors that are likely to affect consumer attitudes towards an environmental CSR initiative and formed a model for this. The model postulates four main factors that are likely to affect consumers attitudes towards an environmental initiative; which attitude a consumer holds towards the actual product (in this case the paper bags) in question, the extent to which a consumer considers environmental responsibility to be important, the extent to which a consumer considers environmental issues to be a threat to her-/himself and the amount of information a consumer receives about the initiative. To test our model we used a quantitative approach and investigated the consumer attitudes towards the initiative no plastic bags at the shopping centre Strömpilen, Umeå. We found that consumers in general are very positive towards the initiative. We then looked closer into what parts of our model that had significant impact on consumer attitudes towards the concept. The Chi-Square tests showed that three of four parts in the model could be verified. These parts were; the consumer’s attitude towards the actual product (in this case the paper bag), how important environmental responsibility is to a consumer and to what extent a consumer sees environmental issues as a threat to her-/himself. The fourth part of the model; the amount of information a consumer has received could not be verified. Thus the model was modified and was in the end constituted by the three parts that had been statistically verified.
|
29 |
An assessment of strategies for the management of plastic bag wastes in Hong KongNg, Ting-leung, Gordon., 吳庭亮. January 1994 (has links)
published_or_final_version / Surveying / Doctoral / Doctor of Philosophy
|
30 |
Children's Influence -Regarding Home Delivery Grocery Bags with Familyfood Optima AB in Focus.Haglund, Josefin, Stenberg, Sophie January 2012 (has links)
Background Children are influencing the family’s decision making process regarding food products. The children’s spending power is increasing and they become consumers in an early age. By influencing the parents, the children make them buy products that they had not planned to buy or make the parents avoid products that they usually would have bought. Online food shopping is increasing in Sweden and the home delivery grocery bag is the category of online food that has increased the most from 2010 to 2011. Familyfood Optima AB is one of the home delivery grocery bags companies that deliver grocery bags in the south of Sweden. Purpose The purpose of this thesis is to find how children affect their parents’ behavior of purchasing home delivery grocery bags. Method To understand how children affect their parents in the decision of home delivery grocery bags a qualitative approach was used where twelve semi-structured interviews were held. Seven of the interviews were held with customers to Familyfood Optima AB. Four interviews were held with non-customers that had been customers to Familyfood Optima AB and one interview was held with a respondent that never had been a customer of a home delivery grocery bag company. Conclusion Children are influencing their parents in the decision to purchase home delivery grocery bags. They also influence the parents in the decision of whether or not to continue purchasing the home delivery grocery bag. The decision of purchasing a home delivery grocery bag depends on the children’s influence and the extent of the parent’s yielding. To influence their parents, the child use both direct and indirect influence techniques and three of the five bases of power. The children’s influence is also dependent on the child’s age and the influence from peers.
|
Page generated in 0.0457 seconds