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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.
101

Evoluce hostitelské specializace a fylogeografie řasníků čeledi Xenidae (Strepsiptera) / Evolution of host specificity and phylogeography of Strepsiptera parsites of the family Xenidae

Benda, Daniel January 2016 (has links)
The twisted-wing parasites (Strepsiptera) are an endoparasitic order of insects with cosmopolitan distribution, which are sister group of Coleoptera. There are about 600 known species up to date. Strepsiptera parasitize seven insect orders (Thysanura, Orthoptera, Blattodea, Mantodea, Hemiptera, Diptera, Hymenoptera). The family Xenidae is one of the most derived groups of Strepsiptera. Its representatives parasitize aculeate Hymenoptera of three families (Vespidae, Sphecidae, Crabronidae). In comparison to the basal groups, there are well-known hosts for genera of the family Xenidae. Therefore, this group is suitable object for study of the evolution of host specialization. Phylogeny of the family Xenidae was constructed on the basis of molecular analysis of three genes. Moreover, the mapping of ancestral host major groups and biogeographic areas was performed using two methods (parsimony, maximum likelihood). According to the results, the family Xenidae is monophyletic group with Old World origin. There were a several independent switches to the same host groups. This significantly changes the existing ideas about evolution of host specialization and requires a taxonomic revision. Within the family Xenidae, there were several cases of dispersal between the Old World and the New World. Furthermore,...
102

Společenstvo motýlů (Lepidoptera) lesního komplexu Loučany u Klatov / Lepidoptera Community of the Woodland Complex Loučany near Klatovy

Rendlová, Veronika January 2016 (has links)
This thesis is focused on faunistic survey of Macrolepidoptera in Loučany (foothills of the Šumava Mts, Czech Republic). The research, involving different capture methods, proceeded from April to November 2015 on given transect and several other habitats. Based on the results (including partial data from 2013 and the last two decades of the 20th century), an inventory of identified species of Macrolepidoptera was made. Altogether 205 species from 16 families were found in Loučany. The most important species are for example the Black-veined White (Aporia crataegi), High Brown Fritillary (Argynnis adippe), Pearl-bordered Fritillary (Boloria euphrosyne), Purple Emperor (Apatura iris), Spruce Carpet (Thera britannica) and Sandy Carpet (Perizoma affinitata). The environmental parameters of experimental sites were noticed during research and the habitat preferences of species were analysed using specialized literature. Altogether 186 species (90,7 % of all identified species) are linked to some kind of woodland habitat. To support present biodiversity of the community of Macrolepidoptera, it is necessary to practice a suitable woodland management, conserving mosaicity and open canopy. Key words: Lepidoptera, species diversity, Czech Republic, Klatovy area, conservation, woodland management
103

Restoration of a wet longleaf pine (Pinus palustris) savanna in southeast Louisiana: Burning toward reference conditions

Entrup, Alex K. 18 December 2015 (has links)
This study quantifies the changes in vegetation composition and structure of a fire-excluded Pinus palustris (longleaf pine) wetland savanna restoration site in southeastern in comparison to a proximate contemporary reference site. The restoration site was invaded by hardwood species and off-site pines, and never underwent extensive soil disturbance. The restoration treatments involved logging across portions of the site and the reintroduction of fire across the entire site. All species present in 10m2 quadrats were recorded prior to treatment and throughout the 17 year study at reference and treatment sites. The community composition of both logged and unlogged sites converged over time, and became more similar to the reference site. We conclude that logging of off-site pine coupled with the reintroduction of frequent fires can be effective in restoring ground cover in remnant longleaf pine savannas withdisturbance.
104

Vegetation response to clearing of exotic invasive plants along the Sabie River, South Africa

Garner, Richard David 26 February 2007 (has links)
Student Number : 9202137P - MSc Dissertation - School of Animal, Plant and Environmental Studies - Faculty of Science / The Reconstruction and Development Programme’s Mpumalanga Working for Water Programme (WWP) has cleared exotic and commercial weed species from the riverine environment since 1994. This study serves as an assessment of the impact and modification caused as a result of invasion and the subsequent clearing of the exotic vegetation on flora in the riverine zone of the Sabie River Catchment. The experimental design compares the before and after clearing effects and includes altitude and invasion intensity variables. The investigations included: in situ soil seed banks, environmental modification, vegetation structure, species diversity and effectiveness of clearing. Clearing and invasion by exotic species altered soil chemical, physical and ground cover parameters. The extent of these modifications was dependent on the extent of invasion and clearing done within the community. Clearing of exotic species however, acted as an additional disturbance to that caused by invasion. Environmental modifications that occurred with clearing and invasion within the study were positively related to percentage soil organic matter, and ground cover (soil, litter, vegetation). Invasion by exotic species alters the vegetation structure, the extent of which was directly related to the invasion intensity. The main source of vegetation structure modification is attributed to tall growing exotic species such as Eucalyptus grandis and Solanum mauritianum. Both of these species dominated the indigenous vegetation, E. grandis by expanding the upper canopy and S. mauritianum by dominating the mid canopy. Clearing of invasive vegetation resulted in an additional disturbance proportional to the extent of invasion intensity. Invasion did not result in any large changes to the vegetation at low intensity but clearing at this intensity increased the disturbance and altered the vegetation structure. Soil seed banks were limited in the number of species and dominated by two exotic species. The soil seed bank of woody species related positively to the community species richness. The total soil seed bank density did not relate to invasion intensity or clearing thereof but propagules of individual species within the soil seed banks did. The seeds of the exotic species, Acacia mearnsii and S. mauritianum, illustrated burial as prerequisite for persistence in the soil seed bank. A. mearnsii and S. mauritianum seeds were found to have half-life’s of up to 25 years and 13 months respectively. The species richness and diversity varied only marginally because of invasion and clearing. Species alpha diversity increased with clearing due to weedy and pioneer species establishment. Beta diversity effectively highlights the species turnover with clearing and invasion. Success in eradication of exotic species had mixed results. Clearing of high invasion sites was effective but in lower invasion categories a number of exotic individuals were missed. Clearing effectiveness was good for certain species such as E. grandis and Pinus patula, but poor for others such as S. mauritianum. Coppicing is a significant issue for E. grandis and S. mauritianum. The persistence of individuals (coppicing & missed individuals) coupled with very large persistent seed banks has repercussions for the clearing programme, as it may prevent effective eradication. Initially the WWP has been successful in removing exotic vegetation, however there is a failure to address the regenerative properties of some exotic species. Unless a rigid schedule of follow up clearing treatments occurs, an even larger invasion problem could exist.
105

Relationship between woody biodiversity and use of non-timber forest products in the Savanna Biome of South Africa

Dovie, Benjamin Delali Komla 16 February 2007 (has links)
Student Number : 9904953T - PhD thesis - School of Animal, Plant and Environmental Science - Faculty of Science / This study seeks to combine the knowledge of science and society to elicit the relationship between the harvesting of woody plant species and the local availability of woody species in South African savannas. Ten villages located in the former communal areas and homelands within three broad vegetation types (i.e., Mixed lowveld bushveld, Eastern thorn bushveld, and Natal lowveld bushveld) were studied. The study, conducted in the framework of the coupled human-environment system poses challenges to both scientists and managers (e.g., setting common goals). Data were collected using modified Whittaker plots (MWP) and focus group discussions (FGD), denoting ecology and society, respectively. There were nine 1000m² MWP plots sampled per village, each having nested 1m², 10m² and 100m² subplots. The FGD involved six groups of local people based on gender and age. The study revealed that the harvesting of woody plant species is a source of local disturbance to woody vegetation. Generally, there were more woody species in locations farther from settlements, having a mean of 41.97 ± 3.9, than for the intermediate (38.27 ± 5.6) and near locations (19.9 ± 4.2) within the 1000m² plots, the result of the reduction in species closer to settlements from higher harvesting levels. The larger sampling plot size of 1000m² of the MWP had the highest diversity, decreasing sequentially to the smallest scale (1m²). The density of the woody species was highest in the intermediate locations (517 ± 80 plants/ha), followed by the far and near, relative to the settlements. The Natal lowveld bushveld broad vegetation type had the highest mean density of trees (573 ± 71 trees/ha) compared to the Mixed lowveld bushveld (366 ± 64 trees/ha) and the Eastern thorn bushveld (312 ± 40 trees/ha). The stem diameters of trees were generally higher in the villages of the Mixed lowveld bushveld than the other two vegetation types. The study reaffirmed that anthropogenic disturbances within savannas impact vegetation and need to be studied concurrently with other disturbance factors (e.g., biotic and abiotic or environmental). The mean total coppice shoots of stumps within the 1000m² plots was relatively higher in the near locations (38.4%), than the far (33.0%) and intermediate (28.7%). This difference in coppicing shows that although near locations were less species rich, which is a result of disturbance, the growth of shoots may nevertheless be greater. Harvesting disturbance will possibly favour the regeneration of some species, as well as the maintenance of biodiversity. Whilst 135 woody species (from a total 191 from 42 plant families) sampled in the field were used by the local people, the community knowledge yielded almost twice as many (267 species, from 69 plant families). The ratio of mean useful woody species to total woody species remained relatively constant at about 1.0:1.1 from the near to far locations around the villages and accompanied by increased woody species diversity with distance from village. The MWP sampling yielded eight broad use categories (i.e., medicinal, wild edible fruits, fuelwood, housing and fencing poles, craft (e.g., carving), cultural, local beverages (e.g., alcohol)), and nine for the FGD (the eight for the MWP plus indigenous furniture). According to the local people, the highest number of species was used for medicine (27.8% of species), followed by fuelwood (19.2%) and wild edible fruits/seeds (19.1%). Over half of the species had multiple uses (i.e., three to eight uses), raising questions of possible threats to their persistence. Useful woody species were not restricted to any particular location or vegetation type. Large sized trees were subjected to even more uses than smaller trees, another source of conservation concern. Fifteen of the woody plant species are presently protected by law in South Africa (e.g., Adansonia digitata, Podocarpus latifolius, Mimusops caffra, Philenoptera violacea), while others are facing various forms of regional threats (e.g., Alberta magna, Catha edulis, Ocotea bullata). There is the need to popularise and make people (both local and outsiders) aware of the state of NTFP species, using local and village level information as an additional criterion for describing conservation threat (e.g., proposed “Locally Brown List” – Chapter 4). The older generation of local people were highly knowledgeable in terms of the woody species used for medicine, craft, fencing and housing poles, the middle aged in beverage making species, and the younger generation in fuelwood species. Overall, older males were highly knowledgeable of the useful species. The generally strong correlation (r = 0.99, p <0.0001) between the cumulative woody species diversity from field and community knowledge suggests the need to integrate data using multi-disciplinary approach and also to manage NTFP species. Although threat reduction assessments (TRA) and monitoring have previously been suggested, the participation of local people, harvesters and users will be crucial in making TRAs effective. In conclusion, the harvesting of NTFPs, and the impacts of the changes in the NTFP species on total diversity in savannas need to be understood in order to move towards a more holistic approach to conserving the woody species that may be at risk of extinction through harvesting. Disturbance criteria that describe harvesting levels should be set to guide research and management protocols. Finally, when discussing NTFPs and the species from which they are harvested, management should aim at incorporating all the factors that affect sustainability, such as land and resource tenure and local participation, the political economy, appropriate production and development cycles.
106

Composição e abundância das espécies de anfíbios e répteis em uma paisagem fragmentada de Mata Atlântica no Estado do Rio de Janeiro / Composition and abundance of amphibians and reptile species in a fragmented landscape of Atlantic Rainforest in Rio de Jaeiro State

Mauricio de Almeida Gomes 22 February 2011 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Neste estudo, procuramos avaliar a composição e abundância de espécies de anfíbios e répteis em uma paisagem fragmentada de Mata Atlântica, no município de Cachoeiras de Macacu, Estado do Rio de Janeiro. Amostramos a herpetofauna da região na área contínua de floresta da Reserva Ecológica de Guapiaçu (REGUA), em 12 fragmentos do entorno com tamanhos e graus de isolamento diferentes, e áreas de pasto (matriz). Utilizamos para amostragem destes animais as metodologias de buscas ativas visuais e armadilhas de interceptação e queda, além de encontros ocasionais. No total foram registradas 55 espécies de anfíbios anuros pertencentes a 12 famílias e entre os répteis foram registradas 26 espécies, sendo uma espécie de anfisbena, uma de jacaré, nove de lagartos e 15 de serpentes. Para os anfíbios, houve uma dominância de espécies da família Hylidae, que representaram mais da metade do total de espécies encontradas no estudo. Já entre os répteis, houve uma predominância de espécies de serpentes da família Dipsadidae. Considerando apenas os registros feitos pelas metodologias empregadas, a área contínua de floresta da REGUA possui uma riqueza de espécies de anfíbios (N = 30) e de lagartos (N = 4) menor do que o conjunto de fragmentos (N = 36 e N = 8), mas superior ao que foi encontrado na matriz (N = 25 e N = 1). Entretanto, para os anfíbios, mais de um terço das espécies (N = 11) que ocorreu na mata contínua não ocorreu nos fragmentos ou na matriz, o que sugere que estas espécies podem ser mais sensíveis a alterações do hábitat. A maior riqueza de espécies encontrada no conjunto de fragmentos pode ser parcialmente explicada pelo fato de muitas espécies tanto de anfíbios quanto de lagartos que são típicas de áreas abertas, terem sua ocorrência favorecida neste tipo de condição de ambiente relativamente menos fechado dos fragmentos. Quando avaliamos o efeito de métricas da paisagem, observamos diferentes respostas entre os anfíbios e os lagartos. Enquanto para os anfíbios houve uma tendência de fragmentos mais distantes terem uma menor riqueza de espécies e de modos reprodutivos associados a estas espécies, para os lagartos a área dos fragmentos parece ser uma importante variável na estruturação das comunidades. Entretanto, por particularidades das características fisiológicas e ecológicas de anfíbios e lagartos, é possível que outros fatores expliquem a distribuição diferenciada das espécies. De forma geral, as áreas de matriz amostradas pareceram ser hostis a espécies florestais tanto de anfíbios quanto de lagartos. Além disso, para anfíbios, a presença de ambientes reprodutivos pode ser fator crucial para a ocorrência de algumas espécies. De forma similar ao encontrado em outros estudos, para a manutenção da diversidade de anfíbios e lagartos na paisagem fragmentada tratada neste estudo é necessário preservar o grande bloco florestal e aumentar a conectividade deste com os fragmentos, o que poderia permitir a área contínua servir de área-fonte de dispersores para os remanescentes florestais. / In this study, we evaluated the composition and abundance of species of reptiles and amphibians in a fragmented landscape of Atlantic Forest in the municipality of Cachoeiras de Macacu, Rio de Janeiro State. We sampled the herpetofauna of the region in continuous forest area of Reserva Ecológica de Guapiaçu (REGUA) in 12 fragments with different sizes and degrees of isolation, and pasture areas (matrix). For sampling amphibians and reptiles we used visual encounter surveys and pitfall traps, supplemented with records obtained in occasional encounters. In total we recorded 55 amphibians species belonging to 12 families and 26 reptiles species, being one amphisbenian, an alligator, nine lizards and 15 snakes. For the amphibians, there was a dominance of species of the family Hylidae, which accounted for over half the total species found in the study. Among reptiles, there was a predominance of species of snakes family Dipsadidae. Considering only the records made by the methodologies employed, the area of continuous forest of REGUA has a species richness of amphibians (N = 30) and lizards (N = 4) lower than the set of fragments conjunctly (N = 36 and N = 8), but higher than that found in the matrix (N = 25 and N = 1). However, for the amphibians, more than a third of species (N = 11) that occurred in the continuous forest did not occur in fragments or in the matrix, suggesting that these species may be more sensitive to changes in habitat. The highest species richness found in the set of fragments can be partly explained by the fact that many species both amphibians and lizards that are typical of open areas, have favored the occurrence of this type of condition relatively less closed environment of the fragments. When we evaluated the effect of landscape metrics, we found different responses between amphibians and lizards. While there was a trend for more distant fragments to keep a lower amphibian species richness and reproductive modes associated with these species, for the lizards, the size of the remnant area seemed to be an important variable in structuring communities. However, by peculiarities of the physiological and ecological characteristics of amphibians and lizards, it is possible that other factors explain the differential distribution of species. In general, the matrix areas sampled appeared to be hostile to both forest species of amphibians and lizards. In addition to amphibians, the presence of reproductive environments can be a crucial factor for the occurrence of some species. As found in other studies, to keep the species diversity of amphibians and lizards in fragmented landscape studied here it is necessary to preserve the large forest block and to increase its connectivity with the surrounding fragments, which could allow the continuous forest area to serve as area-source to dispersers for the smaller remnants.
107

Assessment of small scale tallgrass prairie restoration in an urban environment

Mutch, Paul D. 26 October 2007 (has links)
Tallgrass prairie restoration is an important conservation activity in rural areas. However, little is known about prairie restoration in urban environments. The overall objective of this study was to characterize and better understand urban prairie restoration. This was carried out through an examination of 29 restoration sites within Winnipeg, Manitoba. The results indicated that actively restored urban prairies were successful and high in diversity. Multiple attributes of the restorations were examined as indicators of success including vegetation, the propagule bank and insects. However, not all attributes delivered equivocal results. This suggests that multiple measures should be used to assess a restoration site. Anthropogenic and biophysical variables were found to influence vegetation of the restorations equally, highlighting the importance of incorporating a human component in urban ecological research. These urban restorations were seen to surpass larger rural restorations in quality; thus, efforts should be made to increase their prevalence. / February 2008
108

Avian Community Patterns In The Lesser Caucasus (northeastern Turkey)

Atkin Gencoglu, Gulden 01 December 2007 (has links) (PDF)
ABSTRACT AVIAN COMMUNITY PATTERNS IN THE LESSER CAUCASUS (NORTHEASTERN TURKEY) ATKIN GEN&Ccedil / OgLU, G&uuml / lden M. Sc., Department of Biological Sciences Supervisor: Assoc. Prof. Dr. C. Can Bilgin December 2007, 78 pages Species composition, diversity and species-habitat relations are widely used to describe communities. This study aimed to document diversity, composition and habitat relations of avian communities of the Turkish Lesser Caucasus by using point counts and multivariate analyses. 2845 individuals of 101 bird species were observed at 215 stations located in the study area. Point counts were revealed to be a useful method for terrestrial birds, especially passerines. Species richness and diversity changed significantly within parts of the study area and one particular sub-region was found to be considerably more diverse than the other three. Division of the Lesser Caucasus region into sub-ecoregions may not be justified using bird assemblages since habitat parameters, especially the presence of woody vegetation, seemed to be a better predictor of species composition than geographical proximity. Documented bird and habitat associations provide valuable information on the factors which affect bird occurrence or abundance. Baseline data provided by this study will help detect and understand changes in bird populations in the future. Keywords: avian community, species composition, species diversity, point count method, bird-habitat relationship
109

Vaišvydavos girininkijos medynų vertinimas biologinės įvairovės požiūriu / The Estimation Of Stands Biodiversity In Vaisvydava Forest District

Červokas, Gintaras 21 June 2010 (has links)
Magistro darbe vertinama medynų įvairovė biologinės įvairovės požiūriu ir nustatomos teritorijos palankiausios biologinei įvairovei ir jos apsaugai. Darbo objektas – VĮ Dubravos mokomosios eksperimentinės miškų urėdijos Vaišvydavos girininkijos teritorija. Darbo tikslas - įvertinti Vaišvydavos girininkijos medynus biologinės įvairovės požiūriu ir nustatyti palankiausios biologinei įvairovei ir jos apsaugai teritorijas. Darbo metodai – 1958 m., 1978 m., 1988 m. ir 2003 m. miškotvarkų duomenų analizavimas ir nustatytų medynų rūšinės įvairovės rodiklių vertinimas bei, remiantis girininkijoje esančiomis saugomomis teritorijomis, kertinėmis miško buveinėmis ir retomis rūšimis, charakterizuojama girininkijos biologinė įvairovė ir nustatomos jos koncentracijos vietos. Darbo rezultatai. Atlikus tyrimus nustatyta, kad Vaišvydavos girininkijai tenkančio Dubravos girios masyvo dalyje 1958 m. augo 10, 1978 m. – 12, o 1988 – 2003 m. 13 medžių rūšių. Tai lėmė liepos, tuopos, klevo ir pocūgės atsiradimas medynuose. Nuo 1958 m. iki 1988 m. spygliuočių kiekis medynų sudėtyje didėjo, o nuo 1988 m. užfiksuotas spygliuočių sumažėjimas – jų kiekis medynų sudėtyje sumažėjo 3,6 %. Nagrinėtų įvairovės, proporcingumo bei vyravimo rodiklių dinamika rodo medynų rūšinės įvairovės mažėjimą iki 1988 m. ir didėjimą po 1988 m. Nagrinėjant atskirų augaviečių medynų rūšinės įvairovės dinamiką 1958 – 2003 m., pastebėta, kad didžiausia rūšinė įvairovė buvo Nc, Lc, Ld ir Uc augavietėse. Sudarant palankių... [toliau žr. visą tekstą] / There were estimated stand biodiversity and made biodiversity hotspots network was main object of the master work. The object of the work – Vaišvbydava forest districkt in Dubrava experimental educational state forest enterprise. The aim of the study – to estimate forest stand by biological diversity indexes and to establish the best spots to maintainig the biodiversity in Vaišvydava forest district. Working methods - forest management and data analysis of the stand species diversity indices of 1958, 1978, 1988, and 2003 years, the analysis of preservation territories, key habitats and rare and endangered species, and made biodiversity hotspots network. Study results - Number of trees in the stand in 1958 was 10 and in 1978 years was 12, 1988 and 2003 – 13. This led to the origin of july, poplar, maple and Douglas-fir. Diversity and Proportionality indexes decreased in 1958 – 1988 years period and was increasing in period from 1988 to 2003 years. Dominance index increased in 1958 – 1988 years, because the dominance of the pine and spruce in the stand and was increasing. But the same index was decreased in 2003 years. That happened because the invasion of the Ips typographus to the stands of spruces, and may be influenced in now a day’s politics of silverculture in Lithuania. It means that diversity of stand species is increasing, though it was decreased from 1958 to 1988 years. There were found 12 species of Data Red Book of Lithuania in Vaisvydava forest district, 1... [to full text]
110

Impacts of aggregated retention harvesting on the diversity patterns of nocturnal moth species assemblages in the mixedwood boreal forest of northwestern Alberta

Bodeux, Brett B Unknown Date
No description available.

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