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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

Factors affecting the species richness of old permanent semi-natural grasslands in North-East Scotland

Wilson, Frederick January 2003 (has links)
The successful management for conservation and restoration of semi-natural ecosystems may be achieved only after the factors which regulate plant biodiversity and species composition have been identified. This study investigates the floristic composition and site characteristics of old permanent semi-natural grasslands in North-east Scotland and tests using pot and field experiments the role of soil fertility in determining vascular plant species richness, relative abundance and dynamics of communities. Results from field surveys show that, of the site characteristics quantified, vascular plant species richness is most strongly correlated (negative relationship) with extractable soil phosphorus. Where species richness is high (>40 in a study stand and >17 in a 1 m2 quadrat) extractable soil phosphorus levels (determined by ammonium acetate-acetic acid/polyacrylamide solution extraction and using inductively coupled radio frequency plasma spectrometry by the atomic emission method) are consistently very low (<1.9 mg 1-1 soil) by local agricultural standards. In pot experiments using soil from a site where high species richness is maintained, the loss of forb and graminoid species from synthesised communities may be shown to increase along a nutrient gradient created by incorporating increments of phosphorus. Despite a general increase in the above ground biomass of species which survive, those with the ability to form nitrogen-fixing nodules grow to dominate the community. By comparison, a nutrient gradient created by the incorporation of potassium has little effect on the species richness of synthesised communities. At field sites where the level of extractable soil phosphorus approaches that above which species-rich semi-natural grassland communities are not found to exist, the addition of nitrogen leads to species loss through the dominance of graminoid species. This effect may be intensified by applying phosphorus.
2

Plant Biodiversity across Three Successional Stages in Forests of Southern Illinois

Harper, Leah Wheelbarger 01 December 2020 (has links)
Since the time of European settlement, land-use history, management practices, the introduction of non-native invasive species (NNIS), and climate change have dramatically changed the successional pathways of Southern Illinois forests. Biodiversity is considered essential for ecosystem health and resiliency, so understanding the impact theses forest changes have on biodiversity is necessary to guide future management decisions. This study was conducted at Touch of Nature Environmental Center (TONEC) in Southern Illinois using the Shannon diversity index (H') to compare the levels of biodiversity in the overstory, shrub, seedling, and herbaceous layers across early, mid, and mature successional stages. Twenty plots were randomly placed within early, mid, and mature forest successional stages for a total of 60 plots. Four circular nested vegetation plots were recorded at each plot location. In the overstory plots (area 314.16 m2), woody stems above 6.5 cm diameter at breast height (dbh), age class, and crown were all recorded. In the shrub layer (area 28.27 m2), all woody stems between 2.5 and 6.5 cm dbh were recorded, while in the seedling layer (area 3.14 m2), all woody stems < 1 cm dbh were recorded. In the herbaceous layer, (area 1 m2) species were measured by percent cover. Shannon diversity index (H') was calculated for each plot. When vegetation layers were combined and mean H' within forest successional stages were compared, no differences were found. However, when successional stages were combined within each vegetation layer, the shrub layer had the least H' increasing to seedling, increasing again to overstory and herbaceous; these being equal. When breaking down the vegetation layers separately and comparing H' across successional stages within each, both the overstory and shrub layers had no difference. Early successional was the least diverse in seedling, rising to mid and mature, which were equal. The herbaceous layer showed an opposite trend with early having the highest H' decreasing to mid and decreasing again to mature. Finally looking at the differences across vegetation layers within early, mid, and mature successional stages. Early-successional had the most variability with the highest H' in herbaceous; this decreased progressively to overstory then to shrub and seedling, which were equal. In mid-successional plots, overstory, seedling, and herbaceous layers were equal with H' decreasing in shrub. In mature plots, all vegetation layers had the same H'. Across all vegetation layers, the highest percentage of NNIS was in early-successional, followed by mid, with notably less found in mature forest. Even in instances where H' values were the same, species composition across forest successional stages were quite different. While overall biodiversity is the same across successional stages, differences in H' can be seen when looking at the vegetation layers. Management should focus on removing NNIS in the early and mid-successional forests paying particular attention to the shrub layer, which has the overall lowest H' with the most dramatic differences in composition and the presence of NNIS across all successional stages. Also of concern is the low H' in the seedling layer in early-successional forest, which reduces the likelihood of successful regeneration of these hardwood stands in the future.
3

Browsing Damage of Moose in relation to plant diversity in Gävleborg County, Sweden

Ramirez, Bernabe January 2018 (has links)
For several decades, Moose population (Alces alces) in Sweden has been growing considerably. This increase has resulted in a greater impact and damage in trees, especially in Scots pine (Pinus sylvestris) which is the basis of Swedish forestry and, therefore the economical losses are considerable. For this reason, for several years, to know Moose feeding behaviour and to look for measures to reduce it is impact on forestry have marked the guidelines of research. The Moose damages the pine mainly in winter, when there are no herbaceous plants and deciduous trees to eat. This project has focused on reducing the moose damage from a biodiversity point of view, following a line similar to the "Optimal forage theory". According to this theory, a moose selects the food according to the composition and the richness of the species. Results have conducted to relation plant-richness with Moose Browsing Damage on Scots pine and with more abundance of trees around a Scots pine, Moose Browsing Damage decreases considerably. In this project I also study the association between Moose activity and the plant-richness. Both (Moose Browsing damage on Scots pine and Moose activity) were tested with Shannon´s and Simpson´s index, two biodiversity indexes. The amount of different plants species nearby a Scots pine were measured and studied, as well. Also, I did the Pearson´s coefficient as an initial relationship between the variables (and observed if it is negative or positive) and ANOVA analysis. Although the conclusions weren´t as clear as I expected, in my opinion this study offered another tool to reduce the before mentioned impact.
4

Dinâmica da regeneração natural de um cerrado stricto sensu no nordeste do Estado de São Paulo / Dynamics of the natural regeneration of a cerrado stricto sensu in the Northeast of the State of São Paulo

Souto, Marco Antonio Gomes 19 October 2017 (has links)
A savana pode ser definida, em linhas gerais, como um ambiente com características intermediárias entre campo e floresta. Em virtude de sua grande distribuição geográfica, sendo encontrada em aproximadamente 30% das áreas com estações secas do planeta, existem cerca de 200 definições diferentes para o conceito de savana. O Cerrado brasileiro, classificado como um tipo de savana, acompanha a tendência de apresentar inúmeras definições de acordo com o autor ou região. Apesar disso, pode-se afirmar que o Cerrado é o segundo maior bioma brasileiro ocupando cerca de 21% do território nacional, distribuindo-se em grande extensão norte-sul, apresentando desde formações florestais até campos abertos. No presente estudo define-se cerrado stricto sensu como o ambiente com a presença de árvores de pequeno porte, retorcidas e com ramificações irregulares, geralmente com cascas com cortiça e folhas xeromórficas. O atual estado de conservação das savanas é crítico e, especificamente no estado de São Paulo, essa situação não é diferente, sendo que os remanescentes de cerrado estão sob grandes pressões antrópicas, principalmente a pressão das atividades agrícolas que convertem a paisagem natural por meio da modificação da cobertura vegetal, comprometendo a conservação das áreas naturais, extremamente fragmentadas e alteradas. Dado o atual estado de conservação do cerrado, é fundamental o conhecimento da situação de conservação dos remanescentes e como estão ocorrendo os processos de regeneração natural dessas áreas contribui neste processo, pois para fundamentar qualquer ação de conservação, manejo ou intervenção direta as informações sobre a biodiversidade vegetal são essenciais. Assim, o objetivo deste estudo foi estudar aspectos da dinâmica da regeneração natural da vegetação de um remanescente de cerrado stricto sensu localizado no município de Patrocínio Paulista - SP. Para isso, caracterizou-se a composição do estrato adulto do remanescente, o estrato juvenil, a chuva e banco de sementes, complementando essas informações com dados fenológicos de seis espécies arbóreas, todos estudos realizados em um fragmento de cerrado stricto sensu com 100 ha localizado na Fazenda Santa Cecília, Patrocínio Paulista SP. Os resultados obtidos indicam claramente uma diminuição da biodiversidade vegetal local, onde os estratos regenerativos representam uma amostra muito pequena do estrato adulto atual. Aumentando-se a escala temporal da análise, utilizando os resultados apresentados pelo único estudo fitossociológico realizado no mesmo fragmento no ano de 2004, essa tendência fica ainda mais evidente, reforçando os resultados encontrados no presente estudo. A composição florística do estrato regenerativo com uma diversidade muito aquém do esperado, não apresentando uma biodiversidade compatível com o esperado, indica o fracasso do processo de regeneração no fragmento analisado. O processo de diminuição da biodiversidade vegetal local, com a possível extinção de muitas espécies vegetais em médio e longo prazos, caracteriza o fragmento analisado como um escoadouro de biodiversidade. Esse processo representa um enorme risco para a biodiversidade local e regional, alterando características estruturais e relacionadas à dinâmica da área. Estudos mais detalhados precisam ser desenvolvidos com o intuito de se verificar como as ações (naturais ou antrópicas) estão afetando diferentes componentes naturais (polinizadores, dispersores, aspectos fisiológicos das espécies vegetais etc.) provocando tão rápida diminuição da biodiversidade local. A manutenção em longo prazo da cobertura vegetal de uma área depende, diretamente, da capacidade de conservação e desenvolvimento dos complexos processos relacionados à regeneração natural da comunidade e, se de alguma maneira, esses processos forem afetados, toda a dinâmica natural de uma área pode ser comprometida. / The savanna can be broadly defined as an environment with intermediate characteristics between field and forest. Due to its great geographical distribution, being found in approximately 30% of the dry areas of the planet, there are about 200 different definitions for the savanna concept. The Brazilian Cerrado, classified as a type of savannah, accompanies the tendency to present numerous definitions according to the author or region. In spite of this, it can be affirmed that the Cerrado is the second largest Brazilian biome occupying about 21% of the national territory, being distributed in great north-south extension, presenting from forest formations to open fields. In the present study cerrado stricto sensu is defined as the environment with the presence of small trees, twisted and with irregular branches, usually with bark with cork and xeromorphic leaves. The current conservation status of the savannas is critical and, specifically in the state of São Paulo, this situation is not different, being that the remnants of cerrado are under great anthropic pressures, mainly the pressure of the agricultural activities that convert the natural landscape through the modification of the vegetal cover, compromising the conservation of the natural areas, extremely fragmented and altered. Given the current state of conservation of the cerrado, it is essential to know the conservation status of the remnants and to know how natural regeneration processes are taking place in these areas, since in order to substantiate any conservation action, management or direct intervention information on plant biodiversity are essential. Thus, the objective of this study was to study aspects of the dynamics of the natural regeneration of the vegetation of a remnant of cerrado stricto sensu located in the municipality of Patrocínio Paulista - SP. For this, the composition of the adult stratum of the remnant, the juvenile stratum, rainfall and seed bank were characterized, complementing this information with phenological data of six tree species, all studies carried out on a fragment of cerrado stricto sensu with 100 ha in Fazenda Santa Cecília, Patrocínio Paulista - SP. The results clearly indicate a decrease in local plant biodiversity, where the regenerative strata represent a very small sample of the current adult stratum. Increasing the time scale of the analysis, using the results presented by the only phytosociological study carried out in the same fragment in the year 2004, this trend is even more evident, reinforcing the results found in the present study. The floristic composition of the regenerative stratum with a diversity that is much lower than expected, does not present a biodiversity compatible with the expected, indicates the failure of the regeneration process in the analyzed fragment. The process of decreasing local plant biodiversity, with the possible extinction of many plant species in the medium and long term, characterizes the fragment analyzed as a drainage of biodiversity. This process poses a huge risk to local and regional biodiversity, altering structural characteristics and related to the dynamics of the area. More detailed studies have to be carried out in order to verify how natural or anthropogenic actions are affecting different natural components (pollinators, dispersers, physiological aspects of plant species, etc.), causing a rapid reduction of local biodiversity. The long-term maintenance of the vegetative cover of an area depends directly on the conservation and development capacity of the complex processes related to the natural regeneration of the community and, if in any way, these processes are affected, all the natural dynamics of an area can be compromised.
5

Biodiversité végétale et délaissés dans l'aménagement urbain. Contribution potentielle des délaissés urbains aux continuités écologiques / Plant diversity and wastelands in urban planning. Urban wastelands' potential contribution to ecological connectivities

Brun, Marion 07 December 2015 (has links)
Cette thèse se propose d’éclairer les connaissances sur les délaissés urbains, définis comme temporaires et abandonnés au sein de l’urbain, ne présentant pas de projet d’aménagement immédiat, laissant place à une végétation spontanée. Notre objectif est de caractériser la biodiversité végétale des délaissés urbains afin de comprendre en quoi ils peuvent avoir un rôle en tant qu’espaces de nature en ville et plus spécifiquement dans les politiques de préservation des continuités écologiques, notamment les Trames Vertes et Bleues (TVB). Etant étudiés dans le milieu urbain, il est nécessaire de considérer les délaissés au sein de l’espace géographique qu’est la ville. D’un point de vue écologique, la mise en relation des dynamiques écologiques et des caractéristiques du milieu urbain permet non seulement d’analyser leur intérêt écologique intrinsèque, mais aussi leur rôle potentiel pour les continuités écologiques en ville. Afin d’appréhender ce rôle, il est également nécessaire de saisir la façon dont ces espaces sont pris en compte dans les politiques d’aménagement du territoire et de conservation de la nature. Enfin, les résultats de cette caractérisation pluridisciplinaire des délaissés urbains porteront sur les outils d’aménagement du territoire mobilisables pour améliorer la prise en compte des délaissés au sein des politiques environnementales. / This PhD aims to enlighten knowledge on urban wastelands, defined as abandoned and temporary lots within urban areas that are not included into immediate planning project, allowing spontaneous vegetation to develop. Our goal is to characterize urban wastelands’ biodiversity in order to understand their role as natural spaces in the city and more specifically, with the accession of sustainable development, in ecological continuity preservation policies, including the “Trame Verte et Bleue” tool (TVB). Given that our research is an urban study, it is necessary to consider wastelands within the urban geographical area. From an ecological point of view, linking ecological dynamics with urban characteristics allows to understand their intrinsic ecological value, and their potential role in TVB. To understand this role, it is also necessary to embrace how these spaces are considered in urban planning and conservation policies. Finally, the results of this wastelands’ multidisciplinary characterization focus on the development of tools to improve wastelands’ inclusion in environmental policies.
6

Dinâmica da regeneração natural de um cerrado stricto sensu no nordeste do Estado de São Paulo / Dynamics of the natural regeneration of a cerrado stricto sensu in the Northeast of the State of São Paulo

Marco Antonio Gomes Souto 19 October 2017 (has links)
A savana pode ser definida, em linhas gerais, como um ambiente com características intermediárias entre campo e floresta. Em virtude de sua grande distribuição geográfica, sendo encontrada em aproximadamente 30% das áreas com estações secas do planeta, existem cerca de 200 definições diferentes para o conceito de savana. O Cerrado brasileiro, classificado como um tipo de savana, acompanha a tendência de apresentar inúmeras definições de acordo com o autor ou região. Apesar disso, pode-se afirmar que o Cerrado é o segundo maior bioma brasileiro ocupando cerca de 21% do território nacional, distribuindo-se em grande extensão norte-sul, apresentando desde formações florestais até campos abertos. No presente estudo define-se cerrado stricto sensu como o ambiente com a presença de árvores de pequeno porte, retorcidas e com ramificações irregulares, geralmente com cascas com cortiça e folhas xeromórficas. O atual estado de conservação das savanas é crítico e, especificamente no estado de São Paulo, essa situação não é diferente, sendo que os remanescentes de cerrado estão sob grandes pressões antrópicas, principalmente a pressão das atividades agrícolas que convertem a paisagem natural por meio da modificação da cobertura vegetal, comprometendo a conservação das áreas naturais, extremamente fragmentadas e alteradas. Dado o atual estado de conservação do cerrado, é fundamental o conhecimento da situação de conservação dos remanescentes e como estão ocorrendo os processos de regeneração natural dessas áreas contribui neste processo, pois para fundamentar qualquer ação de conservação, manejo ou intervenção direta as informações sobre a biodiversidade vegetal são essenciais. Assim, o objetivo deste estudo foi estudar aspectos da dinâmica da regeneração natural da vegetação de um remanescente de cerrado stricto sensu localizado no município de Patrocínio Paulista - SP. Para isso, caracterizou-se a composição do estrato adulto do remanescente, o estrato juvenil, a chuva e banco de sementes, complementando essas informações com dados fenológicos de seis espécies arbóreas, todos estudos realizados em um fragmento de cerrado stricto sensu com 100 ha localizado na Fazenda Santa Cecília, Patrocínio Paulista SP. Os resultados obtidos indicam claramente uma diminuição da biodiversidade vegetal local, onde os estratos regenerativos representam uma amostra muito pequena do estrato adulto atual. Aumentando-se a escala temporal da análise, utilizando os resultados apresentados pelo único estudo fitossociológico realizado no mesmo fragmento no ano de 2004, essa tendência fica ainda mais evidente, reforçando os resultados encontrados no presente estudo. A composição florística do estrato regenerativo com uma diversidade muito aquém do esperado, não apresentando uma biodiversidade compatível com o esperado, indica o fracasso do processo de regeneração no fragmento analisado. O processo de diminuição da biodiversidade vegetal local, com a possível extinção de muitas espécies vegetais em médio e longo prazos, caracteriza o fragmento analisado como um escoadouro de biodiversidade. Esse processo representa um enorme risco para a biodiversidade local e regional, alterando características estruturais e relacionadas à dinâmica da área. Estudos mais detalhados precisam ser desenvolvidos com o intuito de se verificar como as ações (naturais ou antrópicas) estão afetando diferentes componentes naturais (polinizadores, dispersores, aspectos fisiológicos das espécies vegetais etc.) provocando tão rápida diminuição da biodiversidade local. A manutenção em longo prazo da cobertura vegetal de uma área depende, diretamente, da capacidade de conservação e desenvolvimento dos complexos processos relacionados à regeneração natural da comunidade e, se de alguma maneira, esses processos forem afetados, toda a dinâmica natural de uma área pode ser comprometida. / The savanna can be broadly defined as an environment with intermediate characteristics between field and forest. Due to its great geographical distribution, being found in approximately 30% of the dry areas of the planet, there are about 200 different definitions for the savanna concept. The Brazilian Cerrado, classified as a type of savannah, accompanies the tendency to present numerous definitions according to the author or region. In spite of this, it can be affirmed that the Cerrado is the second largest Brazilian biome occupying about 21% of the national territory, being distributed in great north-south extension, presenting from forest formations to open fields. In the present study cerrado stricto sensu is defined as the environment with the presence of small trees, twisted and with irregular branches, usually with bark with cork and xeromorphic leaves. The current conservation status of the savannas is critical and, specifically in the state of São Paulo, this situation is not different, being that the remnants of cerrado are under great anthropic pressures, mainly the pressure of the agricultural activities that convert the natural landscape through the modification of the vegetal cover, compromising the conservation of the natural areas, extremely fragmented and altered. Given the current state of conservation of the cerrado, it is essential to know the conservation status of the remnants and to know how natural regeneration processes are taking place in these areas, since in order to substantiate any conservation action, management or direct intervention information on plant biodiversity are essential. Thus, the objective of this study was to study aspects of the dynamics of the natural regeneration of the vegetation of a remnant of cerrado stricto sensu located in the municipality of Patrocínio Paulista - SP. For this, the composition of the adult stratum of the remnant, the juvenile stratum, rainfall and seed bank were characterized, complementing this information with phenological data of six tree species, all studies carried out on a fragment of cerrado stricto sensu with 100 ha in Fazenda Santa Cecília, Patrocínio Paulista - SP. The results clearly indicate a decrease in local plant biodiversity, where the regenerative strata represent a very small sample of the current adult stratum. Increasing the time scale of the analysis, using the results presented by the only phytosociological study carried out in the same fragment in the year 2004, this trend is even more evident, reinforcing the results found in the present study. The floristic composition of the regenerative stratum with a diversity that is much lower than expected, does not present a biodiversity compatible with the expected, indicates the failure of the regeneration process in the analyzed fragment. The process of decreasing local plant biodiversity, with the possible extinction of many plant species in the medium and long term, characterizes the fragment analyzed as a drainage of biodiversity. This process poses a huge risk to local and regional biodiversity, altering structural characteristics and related to the dynamics of the area. More detailed studies have to be carried out in order to verify how natural or anthropogenic actions are affecting different natural components (pollinators, dispersers, physiological aspects of plant species, etc.), causing a rapid reduction of local biodiversity. The long-term maintenance of the vegetative cover of an area depends directly on the conservation and development capacity of the complex processes related to the natural regeneration of the community and, if in any way, these processes are affected, all the natural dynamics of an area can be compromised.
7

Relative vegetation height variation and reflectance of herbaceous-dominated patches in Central Sweden

Santiago, Jo January 2020 (has links)
Semi-natural landscapes are recognized as suitable habitats for different plant species and provide ecosystem services that contribute to increased plant biodiversity. At the stand level, plant biodiversity is influenced by vegetation structure, of which vegetation height is an important parameter. Photogrammetry from drone captured images has the potential to provide a quick and cost-effective analysis of vegetation height. In addition, the relation between spectral signatures and species distribution can indicate where higher plant biodiversity can be found, as species can be identified based on their spectral signature. Spectral signatures are thus used in the current study in conjunction with vegetation height as a proxy for plant biodiversity in herbaceous-dominated patches. Two field surveys were conducted to collect drone data and reflectance data in July and August 2019. Twelve plots of ten metres diametre were delimited in the drone-derived orthophotos around the reflectance readings coordinates. In order to assess vegetation height, the difference between the digital surface model derived from the orthophotos and the national digital elevation model was determined. Two statistical indices were calculated: the modified soil-adjusted vegetation index (MSAVI) and the coefficient of variation of heights (CV). The relationship between the two indices was evaluated as a proxy for plant biodiversity. Drone-derived point clouds can be used to measure vegetation height in herbaceous-dominated environments due to the very fine scale of drone imagery. A possible negative correlation was found between MSAVI and CV on both surveyed months (July r2 = 0.675; August r2 = 0.401) if the outlier plots were removed from the analysis. There is not enough evidence to clearly explain the anomalous behaviour of the outlier plots. Further research is needed to confirm the use of the relationship between vegetation height variability and reflectance as a proxy for plant biodiversity assessment in herbaceous-dominated environments.
8

La biodiversité végétale au service des ingrédients naturels : étude des propriétés antimicrobiennes et antioxydantes d’extraits végétaux et développement d’un conservateur naturel pour l’industrie cosmétique / Plant biodiversity serving natural ingredients : study of antimicrobial and antioxidant properties of plant extracts and development of a natural preservative for the cosmetics industry

Merck, Florence 14 December 2017 (has links)
Cette thèse de doctorat a été réalisée dans le cadre du projet NATUBAVAL visant à découvrir de nouveaux conservateurs naturels pour l’industrie cosmétique, à partir de plantes issues d’un des hotspots mondiaux de biodiversité : le bassin méditerranéen. Dix-sept extraits ont ainsi été obtenus et évalués quant à leurs propriétés antimicrobiennes contre Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus brasiliensis et Candida albicans, ainsi que leur capacité antioxydante. Santolina chamaecyparissus a démontré des propriétés remarquables, et a été sélectionnée pour une étude plus approfondie. Une approche par fractionnement bioguidé a permis l’isolement du composé majoritaire de la fraction la plus active, également identifié comme actif : un spirokétal énol connu de la famille des polyacétylènes. Une optimisation de l’extrait brut d’intérêt a alors été entreprise dans le but de maximiser son activité et de faire face au challenge d’une transposition industrielle et de son incorporation dans un produit cosmétique. En définitive, cette étude introduit une stratégie de développement d’un ingrédient naturel pouvant potentiellement être utilisé comme une alternative aux conservateurs de synthèse dans les produits cosmétiques. / This PhD thesis is part of the NATUBAVAL project that aims at discovering new natural preservatives for the cosmetics industry, issued from one of the world’s biodiversity hotspots: the Mediterranean Basin. Seventeen plant extracts were obtained and screened for their antimicrobial properties against Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus brasiliensis and Candida albicans and their antioxidant capacity. Santolina chamaecyparissus extract was found to present superior properties and selected for further investigation. A bioguided fractionation permitted to isolate the major compound of the most active fraction, that was identified as the active compound, a known spiroketal enol from the polyacetylenes family. An optimization of the crude extract of interest was then performed in order to maximize its activity and to face the challenge of an industrial scale-up and its incorporation in a cosmetic formulation. Finally, this study introduces a natural ingredient development strategy that might potentially be used as an alternative to synthetic preservatives in cosmetics.
9

Soil Quality and Plant Diversity of a Discontinued Golf Course

Leonard, Chloe 03 August 2023 (has links)
No description available.
10

Ecologia e controle da invasão de Pinus elliottii no campo cerrado / Ecology of invasion and management of slash pine in a Brazilian savanna

Abreu, Rodolfo Cesar Real de 28 May 2013 (has links)
Os impactos negativos que as espécies invasoras causam aos ecossistemas naturais ou seminaturais são noticiados há pelo menos seis décadas em diferentes partes do mundo. Diversos estudos têm sido realizados visando diagnosticar o processo de invasão, conhecer a ecologia das espécies invasoras e gerar subsídios para o manejo, controle ou erradicação daquelas que causam problemas. No Brasil, a invasão de ecossistemas naturais começou a ser estudada recentemente e muito conhecimento ainda precisa ser gerado para basear a tomada de decisões sobre o problema. Este estudo teve por objetivo descrever o processo de invasão do Cerrado por Pinus elliottii e buscar técnicas de manejo viáveis ecológica e economicamente para o controle da invasora. O estudo foi realizado na Estação Ecológica de Santa Bárbara, no munícipio de Águas de Santa Bárbara, São Paulo, em duas frentes de pesquisa: uma para estudar a ecologia da espécie invasora, e a outra para verificar qual seria a técnica de controle mais vantajosa ecológica e economicamente. O estudo de ecologia baseou-se na amostragem de cinco blocos de 10 parcelas, cada uma com área de 10 x 10 m, para o estudo de plantas nativas com altura a partir de 50 cm e, dentro de cada parcela, cinco subparcelas de 1 x 1 m para o estudo de plantas com altura inferior a 50 cm. Em cada bloco as parcelas foram instaladas de forma que todo o gradiente de invasão por P. elliottii (desde 0 até 100% invadido) fosse contemplado. A densidade e a riqueza de espécies vegetais, agrupadas quanto à forma de vida, foram analisadas como variáveis resposta ao processo de invasão. Nessas parcelas foram caracterizadas, como variáveis explanatórias, a área basal da espécie invasora, a profundidade da camada de acículas e a abertura de dossel, que poderiam explicar as perdas de diversidade. O experimento de manejo foi realizado em uma área de 70 x 50 m, subdividida em 35 parcelas de 10 x 10 m. Sete tratamentos de erradicação (com cinco réplicas) foram testados, correspondendo a diferentes técnicas de manejo, que foram aplicadas isoladas ou combinadas. As técnicas de controle incluíram o corte raso com motosserra, a injeção de herbicida nos troncos e a aplicação de queimada prescrita. Após a aplicação dos tratamentos, a vegetação espontânea de cerrado foi monitorada por dois anos e comparados os tratamentos, utilizando-se a densidade e a riqueza de plantas nativas em regeneração como indicadores ecológicos de sucesso das técnicas. A viabilidade econômica foi analisada com base em todos os custos envolvidos em cada técnica, discutidos mediante a estimativa do custo do controle precoce da invasão. A pesquisa como um todo possibilitou a descrição, em detalhes, do processo de invasão, assim como a quantificação das perdas de diversidade e identificação dos filtros ecológicos envolvidos no processo. O estudo ecológico mostrou que a espessa camada de acículas depositada pela árvores invasoras quando a invasão se adensa é o principal fator responsável pelo desaparecimento de gramíneas, ciperáceas e indivíduos herbáceos, ou seja, quanto mais acículas depositadas no solo, maior a perda dessas formas de vida. Já o fechamento do dossel provocado pela entrada das árvores invasoras no ambiente savânico prejudicou especialmente os arbustos, fazendo com que desaparecessem em ambientes mais sombreados. Não foi notada nenhuma influência das variáveis estudadas sobre espécies arbóreas em regeneração na comunidade invadida. No experimento de manejo, diversos tratamentos foram economicamente viáveis, especialmente quando se prevê a comercialização da lenha das árvores invasoras. Isto porque a receita gerada com a venda da madeira pode cobrir os custos de manejo. Além da viabilidade econômica, ao longo dos dois anos de acompanhamento, o tratamento que combinou corte raso com queima das acículas foi o mais indicado, pois cobriu os custos de erradicação e, dentre os tratamentos testados, foi o que apresentou a melhor regeneração natural da vegetação nativa de cerrado. No entanto, a restauração passiva (regeneração natural) do ecossistema densamente invadido após a erradicação é um processo extremamente lento, de modo que os dois anos de estudo levam a crer que intervenções de restauração por meio de plantio serão necessárias para acelerar o processo. Com esta pesquisa, portanto, foi possível compreender os fatores e processos que levam à perda de biodiversidade decorrente da invasão por Pinus elliottii e, também, assegurar que é possível a erradicação da espécie invasora. Mas a restauração das áreas densamente invadidas ainda é um obstáculo a ser vencido. Os custos ecológicos e econômicos envolvidos na solução do problema são elevados, mas podem ser minimizados caso seja realizado o controle precoce da invasão. / Damages caused by invasive species in natural or semi-natural environments have been noticed for at least six decades in different parts of the world. Meanwhile around the world several studies aim to diagnose the invasion process, the ecology of invasive species and to generate knowledge about management, control, or eradication of these species. In Brazil, the studies about invasive species started recently and a lot of research is still needed to support the decision-making, and consequently strengthen the connections between scientists and decision makers. This work aims to describe the invasion process of slash pine in the Cerrado and seek for management solutions to deal with the invasion problem. The study took place at the Santa Bárbara Ecological Station, a reserve located at Águas de Santa Barbara municipality, São Paulo state. Two distinct types of research were performed: the first one focused on the study of the invasion ecology of slash pine, and the second aiming to seek for the ecologically and economically most viable management technique to remove the invasive species from this ecosystem. The ecological study was based on sampling of native plants taller than 50 cm, taken from five blocks of 10 plots (plot area = 10 x 10 m). To study the plants smaller than 50 cm height, samples were taken from five 1 x 1 m subplots placed inside each plot. In each block, the plots were placed with the aim of contemplating the whole range of invasion gradient (0% to 100% of invaded area) by P. elliottii. Native plant species were grouped according to their life form, and their density and richness were considered as response variables to the invasion process. In this plots, the basal area of the invasive species, pine needles depth and canopy openness were considered as the explanatory variables, as the oscillations of these variables could justify biodiversity losses. The management experiment was performed in a 70 x 50 m area, divided in 35 plots (10 x 10 m). Seven eradication treatments (with five replicates) were established according to different management techniques applied together or isolated. The control techniques included clear-cut with chainsaw, herbicide injection inside the trunks and prescribed burning. After the application of the treatments, the spontaneous recovery of the grassland vegetation was monitored, and the density and richness of native species were used as indicators of the ecological success of the management techniques. The economical viability was analyzed based on all the costs related to each one of the techniques and compared to an initial invasion control. In general, this work described in details the invasion process at the Cerrado vegetation, quantified biodiversity losses and identified the ecological filters in the invasion process. The increase of the pine needle layer thickness is the main driver of the disappearance of grasses, sedges and forbs. The canopy closure caused by the invasive trees in the open savanna environment was responsible for the decrease of shrubs. None of the explanatory variables influenced the native tree species under regeneration. The management experiment pointed several treatments as economically viable, especially when the timber of the invasive species can be commercialized and, thus, the profits obtained from the sold timber can cover the costs regarding the eradication procedure. In addition to the economical viability, over two years of monitoring the native vegetation, the best treatment was the one that combined clearcut and prescribed fire. Under this combination of treatments, the spontaneous regeneration of native vegetation had the best performance, and the eradication costs could be covered.. Meanwhile, the passive restoration (natural regeneration) from a densely invaded ecosystem is an extremely slow process. Therefore, after two years of research, it seems reasonable to assume that interfering in the restoration process through plantation is necessary in order to speed up the vegetation recovery. In this work, thus, it was possible to understand the factors and process that cause biodiversity losses promoted by slash pine (Pinus elliottii) invasion in the Cerrado, and also to ensure that the eradication of this invasive species is possible in this type of ecosystem. Nevertheless, the restoration of heavily invaded areas is still an issue. The ecological and economic costs related to this problem are high but can be reduced when the early control of the invasion is performed.

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