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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.
61

Biologia reprodutiva, distribuição espacial e conservação de Hadrolaelia coccinea (Lindl.) Chiron & V.P. Castro (Orchidaceae, Laeliinae) no Parque Estadual do Ibitipoca, Minas Gerais, Brasil

Delgado, Camila Nardy 19 February 2018 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-06-29T13:51:11Z No. of bitstreams: 1 camilanardydelgado.pdf: 2878569 bytes, checksum: 01348a6b4341b7dfc61de3398541bd78 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-07-03T14:25:28Z (GMT) No. of bitstreams: 1 camilanardydelgado.pdf: 2878569 bytes, checksum: 01348a6b4341b7dfc61de3398541bd78 (MD5) / Made available in DSpace on 2018-07-03T14:25:28Z (GMT). No. of bitstreams: 1 camilanardydelgado.pdf: 2878569 bytes, checksum: 01348a6b4341b7dfc61de3398541bd78 (MD5) Previous issue date: 2018-02-19 / As interações ecológicas são de extrema importância para todo ecossistema, as relações entre plantas e polinizadores possuem um papel estruturador para os sistemas naturais e agrícolas. A fase reprodutiva é um momento marcante na vida de qualquer organismo, influenciado pelas condições bióticas e abióticas, que desenha as características reprodutivas. Desta forma, a distribuição das espécies está altamente relacionada com os mecanismos de dispersão e condições do local para determinar a densidade e a alta diversidade de espécies, que encontramos no planeta. Além disso, muitas vezes o impacto antrópico é um fator marcante em toda essa relação. Orchidaceae é uma família cosmopolita encontrada em quase todos os continentes da Terra, exceto na Antártida, com cerca de 24500 espécies. No Brasil o domínio da Floresta Atlântica se destaca em número de espécies, chegando a 50% de todas as espécies encontradas no país. Laeliinae é a terceira maior subtribo de Orchidaceae, com cerca de 2080 espécies exclusivamente distribuídas na Região Neotropical, sendo muitas vezes desejadas por colecionadores devido à imensa diversidade morfológica e cromática de suas flores. Hadrolaelia coccinea (Lindl.) Chiron & V.P.Castro ocorre nas regiões Sul e Sudeste do Brasil, sendo endêmica do domínio Atlântico. As flores têm como característica principal sua coloração vermelho intenso, tendo grande apelo ornamental. No Parque Estadual do Ibitipoca esta espécie possui um histórico de coleta predatória, onde uma subpopulação está extinta no local. Deste modo, foi realizado um estudo avaliando aspectos da biologia reprodutiva, distribuição espacial e impacto antrópico no intuito de avaliar a situação da espécie no referido parque. No primeiro capítulo foi realizado um estudo de biologia reprodutiva avaliando fenologia, ocorrência de possíveis polinizadores, aspectos da biologia floral, sistema de cruzamentos, e sementes viáveis de frutos provenientes da polinização natural, através do teste do tetrazólio. O sistema de floração encontrado é anual com duração intermediária, como principal estratégia GFD – Generalized Food Deception, por não oferecer recompensa floral para seu polinizador, enganando-o pela semelhança cromática com outra espécie, a qual compartilha características morfológicas e que oferta néctar. Pelas características florais, o mecanismo de polinização é “Key-hole flower” tendo o beija-flor como potencial polinizador. Apresenta um sistema autocompatível e alogâmico, com a polinização cruzada como via de regra, visto que existe a presença de uma barreira física que evita a autopolinização. Por conseqüência, apresenta baixa taxa de frutificação, mas com elevado número de sementes. No segundo capítulo foi avaliada a distribuição espacial de H. coccinea através de transectos de 200 x 8 m distribuídos no interior e borda da nanofloresta nebular, na transição com o arbustal nebular. Sua distribuição espacial foi avaliada através do Índice Morisita (IM) e da Razão da Variância/Média (R). Os indivíduos nos dois ambientes foram contabilizados em grupos de jovens e adultos, registrando-se os forófitos. A significância estatística dos testes foi comparada pelo teste t. A correlação da circunferência do tronco com a abundância de indivíduos de H. coccinea foi feita através de uma regressão linear. Os resultados mostraram um padrão de distribuição agregada, com diferença de abundância entre os ambientes de interior e borda da nanofloresta nebular, mas a densidade de indivíduos jovens e adultos não teve diferença significativa. Há preferência por uma espécie de forófito, Eremanthus erythropappus (DC.) MacLeish (Asteraceae), popularmente chamada de candeia, com o CAP apresentando uma pequena influência na densidade de indivíduos nos forófitos. No terceiro capítulo foi avaliado o impacto antrópico sobre H. coccinea pela atividade de turistas, através do estabelecimento de quatro transectos de 200 x 8 m em dois ambientes, onde a passagem dos turistas não é permitia (ST) e em que a passagem é permitida (T), e registrada a abundância de indivíduos nos forófitos. A significância estatística foi realizada pelo teste Mann-Whitney. A subpopulação onde a passagem dos turistas é permitida está com uma baixa taxa de indivíduos, contrapondo o que ocorre no ambiente em que a passagem de turistas não é permitida (ST), apresentando uma subpopulação com elevado número de indivíduos. / Ecological interactions are of extreme importance to every ecosystem, once the relationships between plants and pollinators have a structuring role for natural and agricultural systems. The reproductive phase is a defining moment in the lifecycle of any organism, influenced by the biotic and abiotic conditions, that draws the reproductive characteristics. In this way the distribution of the species is highly related to the mechanisms of dispersion and conditions of the place to determine the density and the high diversity of species that we find in the planet. Furthermore, often the anthropogenic impact is a striking factor in this whole relationship. Orchidaceae is a cosmopolitan family found in almost all continents of the Earth, except in Antarctica, with about 24500 species. In Brazil the domain of the Atlantic Forest stands out in number of species, reaching 50% of all species found in the country. Laeliinae is the third largest subtribe of Orchidaceae, with about 2080 species exclusively distributed in the Neotropical Region, being often desired by collectors due to the morphological and chromatic diversity of their flowers. Hadrolaelia coccinea (Lindl.) Chiron & V.P.Castro occurs in the South and Southeast regions of Brazil, being endemic to the Atlantic Domain. The flowers are main characteristic is its intense red color, with great ornamental appeal. In the Parque Estadual do Ibitipoca this species has a predatory collection history, where a subpopulation is extinct in the place. In this way, a study was carried out evaluating aspects of the reproductive biology, spatial distribution and anthropogenic impact in order to evaluate the situation of the species in said park. In the first chapter the study of biology reproductive was fullfiled assessing phenology, possible pollinators, aspects of floral biology, crossing systems and viable sees of natural pollinations, through the tretazolium test. The system is described annual - flowering patterns, with main strategy - GFD – Generalized Food Deception, for not offering floral reward for its pollinator, deceiving him through the another species with which she shares morphological characteristics and which offer nectar. By the floral characteristics the mechanism of pollination is "Key- hole flower" having the hummingbird as a potential pollinator. It presents a self- compatible and allogamic system, with cross-pollination as a rule, since there is the presence of a physical barrier that avoids self-pollination. Consequently, it presents a low fruiting rate, but with a high number of seeds. In the second chapter was evaluated the spatial distribution through of four transects of 200 x 8 m distributed inside and border of dwarf cloud forest, in transition cloud shrub. Your spatial distribution was evaluates through os Índice Morisita (IM) Variance/Avarage rate (R). The individuals in the both environment were accounted in groups of youth and adults, registering the forophytes. The statistical significance of test was compared by test t. The correlation of circumference of the trunks with the abundance of individuals of H. coccinea was done through of a linear regression. The results showed an aggregate distribution pattern, with differences of abundance between the interior and border environments of the dwarf cloud forest, but the density of young and mature individuals did not have significant difference. There is a preference for a species of phorophyte, Eremanthus erythropappus (DC.) MacLeish (Asteraceae), popularly called candeia, with CAP having a small influence on the density of individuals on the phorophytes. In the third chapter we evaluated the anthropogenic impact on H. coccinea in areas where the circulation of tourists, through the establishment of four transects of 200 x 8 m in two environment, at where tourists pass are allowed (T) and circulation is not allowed (ST), and registrer the abundance of individuals in the forophytes. The statistical significance was fulfill of Mann-Whitney. The subpopulation of T presents a low rate of individuals, opposing what occurs in the environment ST, which presents a subpopulation with high number of individuals.
62

Biomassa de epífitas vasculares em floresta de restinga na Mata Atlântica / Biomass of vascular epiphytes in seasonally flooded coastal forest (restinga) in the Atlantic Forest

Bakker, Yvonne Vanessa, 1975- 27 August 2018 (has links)
Orientador: Simone Aparecida Vieira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T10:19:45Z (GMT). No. of bitstreams: 1 Bakker_YvonneVanessa_M.pdf: 1853475 bytes, checksum: 2ff87ee7761a486f4b4ef47d5be567c8 (MD5) Previous issue date: 2015 / Resumo: A Mata Atlântica é um dos principais biomas do mundo sendo considerada um dos 25 hotspots de biodiversidade. Dentre os ecossistemas associados à Mata Atlântica, a Floresta de Restinga foi quase totalmente dizimada, restando apenas 0,5% de sua área original. A Restinga se caracteriza por ocorrer nos cordões arenosos ao longo da costa onde o solo é distrófico e sujeito a inundações sazonais. Entre as comunidades que ocorrem nas florestas de restinga, destacam-se as epífitas vasculares que, por não terem contato com o solo, possuem adaptações ecológicas que garantem a aquisição de nutrientes via deposição seca e úmida. Para avaliar o papel das epífitas vasculares no funcionamento das Florestas de Restinga realizou-se o levantamento quantitativo da biomassa das epífitas vasculares em uma área de um hectare de Floresta de Restinga, no Núcleo Picinguaba do Parque Estadual da Serra do Mar (PESM), no litoral norte paulista, município de Ubatuba. Para tanto, foi coletado todo o material epifítico presente em 23 forófitos com DAP entre 4,9 e 41,7 cm, previamente selecionados. Cada forófito foi dividido por zonas ecológicas (copa, galhos e tronco), buscando amostrar os indivíduos arbóreos com diferentes (a) arquitetura de copa (A, para palmeiras; B para copa pequena e C, para copa grande) e (b) índice de cobertura por epífitas (ICE) que classifica os indivíduos arbóreos de acordo com o porte e a biomassa das epífitas. Esse material foi então separado e determinado o peso seco por grupos de epífitas: Arácea (Araceae, Gesneriaceae e Piperaceae), Bromeliacea, Orchidaceae e Miscelânia (Cactaceae, Pteridófitas, raízes, e solo aéreo). A zona ecológica que apresentou maior biomassa epifítica foi o tronco, com 54% do total, seguida pelos galhos com 45% do total. A biomassa epifítica variou de 0,01 kg a 28,9 kg por forófito. A biomassa epifítica total de um hectare de floresta, foi estimada em 2,32 Mg ha-1 representando apenas 1,34% de toda biomassa viva acima do solo, no entanto sua contribuição é de 18% da biomassa fotossintetizante da floresta e de mais de 10 Mg ha-1 de biomassa fresca evidenciando a importante contribuição do componente para o funcionamento do ecossistema. A estimativa de biomassa através do modelo alométrico desenvolvido neste estudo, utilizando-se como variáveis preditoras o índice de cobertura por epífitas e o DAP do forófito, representa um importante avanço nos estudos que envolvem a quantificação da biomassa de epífitas vasculares, sendo de fácil utilização e passível de aplicação em diferentes fitofisionomias, permitindo a comparação entre estudos distintos / Abstract: The Atlantic Forest is one of the most important biomes of the world and is considered one of the 25 hotspots of biodiversity. Among the ecosystems associated with the Atlantic Forest, one of the more endangered is the Restinga Forest with only 0,5% of its original area preserved. Restinga is the seasonally flooded coastal forest that occurs in sandy ridges along the coast where the soil is extremely poor in nutrients, very acid and subject to seasonal flooding. Among the communities that occur in Restinga forest, we highlight the vascular epiphytes that by not depending on soil nutrients, may play an important role in nutrient dynamics in these systems. To evaluate the role of vascular epiphytes in Restinga Forests, this study proceeded a quantitative survey of the biomass of vascular epiphytes in an area of one hectare of Restinga forest, in Picinguaba at the Serra do Mar State Park (PESM), Ubatuba, north coast of São Paulo State. On 23 phorophytes with diameter at breast height (DBH) ? 4.8 cm, previously selected, was all the epiphytic material collected, divided by ecological zones (canopy, branches and trunk). The trees were sample trees with different (a) canopy architecture (A, to palm trees; B, to small crown; and C, for large crown) and (b) coverage ratio by epiphytes (ICE), which classifies individual trees according to the size and biomass of epiphytes. This material was separate and determined the dry weight per epiphytes groups: Arácea (Araceae, Gesneriaceae and Piperaceae), Bromeliacea, Orchidaceae and Miscellany (Cactaceae, Pteridophytes, roots, organic matter). The ecological zone with the highest biomass epiphytic was the trunk, with 54% of the total, followed by branches with 45%. An allometric model for the estimation of epiphytes biomass as a function of the host tree DBH, ICE and dry weight of epiphytes was develop based in the information collected. From this model, biomass of vascular epiphytes was estimate in 2,32 Mg ha-1 for 1ha of Restinga forest. The epiphytic biomass per host tree varied from 0.01 kg to 28.9 kg. The total epiphytic biomass represent only 1.34% of all living biomass above ground (AGB), but its contribution is 18% of the photosynthetic biomass of the forest and more than 10 Mg ha-1 of wet biomass, showing the importance of this component to the functioning of the ecosystem. The estimate of biomass through allometric model developed in this study, using as predictors the epiphyte coverage index and the DAP of the host tree, represents an important advance in studies involving the quantification of biomass of vascular epiphytes, being easy to use and applicable in different vegetation types, allowing comparison between different studies / Mestrado / Ecologia / Mestra em Ecologia
63

Epiphyte diversity and microclimate of the tropical lowland cloud forest in French Guiana

Gehrig-Downie, Christine 30 May 2013 (has links)
No description available.
64

Bekämpning av almsjuka med vaccinpreparat : konsekvenser för den biologiska mångfalden i almar / Control of Dutch elm disease with vaccine preparation : consequences of biodiversity in elm trees

Hansson, Tobias January 2022 (has links)
Biodiversitet innebär en hög artsammansättning och är viktigt för fungerande ekosystem. Almar (Ulmus-arter) är ett träd som hyser en mängd andra arter och som värderas högt i urbana miljöer. Almar drabbas tyvärr av svampsjukdomen almsjukan som leder till att trädet dör. Detta kan dock motverkas med hjälp av vaccinet Dutch Trig®. Det är känt att vaccinet motverkar almsjukan men kunskapen om vaccinet möjligen påverkar andra arter och organismer än almsjukan är låg. Denna studie utfördes i syfte att undersöka och jämföra om epifyters mångfald och allmäntillståndet mellan ovaccinerade och vaccinerade almar skiljde sig. Metoden för studien delades upp i två delar, en tillväxtmätning och visuell granskning samt en kartläggning av epifyter. Resultatet och analysen visade att skillnaden mellan grupperna hos en variabel var signifikant, hos resterande variabler kunde skillnaderna bero på slumpen. Trots detta kunde ändå vissa mönster utläsas och slutsatsen att det fanns en skillnad både i allmäntillstånd och biodiversitet kunde dras.
65

Response of epiphytic lichens to 21st Century climate change and tree disease scenarios

Ellis, C.J., Eaton, S., Theodoropoulos, M., Coppins, B.J., Seaward, Mark R.D., Simkin, J. 25 October 2014 (has links)
No / Characterising the future risk to biodiversity across multiple environmental drivers is fraught with uncertainty and is a major conservation challenge. Scenario planning - to identify robust decisions across a range of plausible futures - can aid biodiversity conservation when tactical decisions need to be made in the present-day, yet consequences are realised over many decades. Management responses to the impact of tree disease are an excellent candidate for scenario planning, because actions to reduce an imminent biodiversity threat need to be effective in the long-term by accounting for concomitant factors such as a changing climate. Lichen epiphytes were used to exemplify a guild sensitive to woodland change, such as a tree disease impact. Bioclimatic models for 382 British epiphytes were combined with species-specific tree association values, to explore scenarios of tree disease (ash dieback), climate change, and range-filling under a lower SO2 pollution regime, for northern Britain focussed on Scotland. Results indicated: 1. Exposure of lichen diversity to projected climate change is spatially structured and expected to be greater in continental northeast Scotland, compared to oceanic western Scotland. 2. Impact of tree disease showed analogous geographic trends, evidencing a critical interaction between the climatic and local ecological setting. On average, the loss of ash could have an effect on epiphyte assemblages comparable in magnitude to that of climate change under a 2080s high emissions scenario. 3. In general, tree disease impacts can be mitigated by increasing the diversity of substitute tree species within a stand, to generate complementarity among epiphyte communities. However, the effectiveness of alternate management scenarios varied locally between sites and temporally with the progression of climate change. Given this variability, scenario analysis is recommended to effectively manage for resilience, by scoping how local factors (e.g. managed woodland composition) can reduce epiphyte assemblage turnover beyond that uniquely associated with larger-scale environmental impacts. (C) 2014 Elsevier Ltd. All rights reserved.
66

Investigating the response of subtropical forests to environmental variation through the study of the Abies kawakamii treelines in Taiwan

Greenwood, Sarah January 2014 (has links)
Altitudinal treeline advance represents a sensitive and well-studied example of species response to climate warming. Although a great deal of work has been conducted globally, few studies have considered subtropical alpine treelines and little is known about their structure and function. This research aims to investigate the response of high altitude forests in Taiwan to climate variation by characterising treeline advance in the area, exploring the mechanisms driving the advance, and considering the consequences of advance for the wider community. The thesis consists of a general introduction to the topic followed by a series of papers, exploring: (1) Possible consequences of treeline shifts for biodiversity and ecosystem function. (2) The advance of the Abies kawakamii treeline through aerial photograph analysis. (3) The changes in growth rate of Abies kawakamii at treeline and the influence of altitude and temperature on growth. (4) Regeneration patterns at treeline and the importance of microclimate and topographic sheltering. (5) Consequences of the range shift for the wider forest community. The work is then concluded with a general discussion and synthesis. The main aims of this work are therefore to characterise and understand the pattern and pace of treeline advance and forest structural change throughout the Central Mountain Range of Taiwan. Treeline advance is characterised through the study of repeat aerial photographs and the mechanisms behind the observed shift are explored through the study of two key responses associated with forest advance: tree growth at treeline and seedling establishment beyond treeline. The consequences of treeline advance for the wider subalpine community are investigated through the study of epiphytic lichen communities at treeline sites. This investigation of an understudied region will allow for improved understanding of treeline response at a global scale.
67

Die Bedeutung der Epiphyten im ökosystemaren Wasser- und Nährstoffumsatz verschiedener Altersstadien eines Bergregenwaldes in Costa Rica / The significance of epiphytes to water and nutrient fluxes in different successional stages of a montane rainforest in Costa Rica

Köhler, Lars 31 October 2002 (has links)
No description available.
68

Effects of forest structure and dynamics on vascular epiphyte assemblages - Functional trait analyses and modelling studies

Petter, Gunnar 02 May 2016 (has links)
No description available.
69

Spatial complexity and microclimatic responses of epiphyte communities and their invertebrate fauna in the canopy of northern rata (Metrosideros robusta A. Cunn.: Myrtaceae) on the West Coast of the South Island, New Zealand

Affeld, Kathrin January 2008 (has links)
Rain forest canopies are renowned for their very high biodiversity and the critical role they play in key ecological processes and their influence on global climate. Despite that New Zealand supports one of the most diverse and extensive epiphyte flora of any temperate forest system, few studies have investigated epiphyte communities and their invertebrate fauna along with factors that influence their distribution and composition. This thesis represents the first comprehensive study of entire epiphyte communities and their resident invertebrate fauna in the canopy of New Zealand’s indigenous forests. The aim of this study was to determine spatial patterns of epiphyte and invertebrate species richness, abundance and community composition in relation to abiotic variables, and in particular, the responses of these communities to elevated temperature and rainfall. This study was carried out in coastal lowland podocarp-broadleaved forests at two sites on the West Coast of the South Island of New Zealand. Samples from 120 mat-forming epiphyte assemblages located on inner canopy branches of 40 northern rata (Metrosideros robusta) trees were studied to characterise the component flora and fauna. Additionally, biomass, branch and tree characteristics and community responses to treatments designed to elevate temperature and rainfall to simulate predicted climate change were measured. This investigation revealed astonishing diversity and functional complexity of epiphyte and invertebrate life in this ecosystem. The 30.6 kg (dry weight) of epiphyte material collected contained a total of 567 species, 170 epiphyte and 397 invertebrate (excluding immature specimens and mites) species, including at least 10 species new to science and many undescribed species Epiphyte communities were found to be dominated by non-vascular plants (80 % of the total species richness), particularly liverworts and invertebrate communities were dominated with respect to abundance (~ 80 % of the total individuals) by Acari, Collembola and Hymenoptera (primarily ants) and functionally by scavengers and ants. Epiphyte and invertebrate communities were highly variable with respect to spatial patterning of species richness, abundance and composition across sites, among trees within sites and among branches within trees. Overall, a highly significant proportion, > 75 %, of the variance could be attributed to differences at the branch level, but these differences could not be explained by the environmental factors measured. There were no consistent relationships between the spatial pattern of epiphytes and invertebrates, or between vascular and non-vascular plants. However, there were significant positive correlations between epiphyte biomass and invertebrate species richness (r = 0.472; p < 0.0001) and abundance (r = -0.395; p < 0.0001), as well as non-living epiphyte biomass and scavenger species richness (r = 0.4; p < 0.0001). Microclimatic measurements taken on epiphyte mats were also highly variable with respect to temperature and relative humidity at similar physical locations within the same tree as well as across trees within sites. There was also considerable variation in the intensity and frequency of climatic extremes, although potentially harmful climatic conditions were experienced by all the epiphyte mats for which weather variables were measured. Negative correlations existed between both epiphyte and invertebrate community composition and increased temperatures expressed as cumulative degree days above 5˚C. However, variability was such that there was no direct evidence that increased temperature and rainfall treatments had an effect on invertebrate species richness, abundance or diversity. Northern rata host trees harbour an astonishingly diverse and complex canopy flora and fauna that is characterised by high spatial variability. Such variability highlights that to determine species distribution and community dynamics in canopy habitats in response to disturbance caused either by climate change or invasive species the structure of entire communities at different taxonomic and spatial scales, along with their responses to microclimatic factors, need to be studied. If such complexities are not taken into account, inappropriate interpretation may result in poor decisions concerning the conservation status, vulnerability and subsequent management of such unique ecosystems.
70

Factors controlling the lower elevational limits in tropical montane plants in the Andes and their implications under the current climatic change / Untere Höhengrenzen der Verbreitung von Pflanzenarten in den bolivianischen Anden und ihre Reaktionen auf zukünftige Klimaveränderungen

Jacome Reyes, Jorge Hernan 03 November 2005 (has links)
No description available.

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