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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.
21

Abundância de fungos entomopatogênicos da ordem Hypocreales e diversidade genética de Metarhizium spp. isolados de amostras de solo de áreas representativas de cinco biomas brasileiros / Abundance of entomopathogenic fungi of the order Hypocreales and genetic diversity of Metarhizium spp. isolated from soil samples of areas representative of five Brazilian biomes

Ana Beatriz Riguetti Zanardo 25 June 2015 (has links)
Os fungos entomopatogênicos dos gêneros Metarhizium, Beauveria e Isaria (Ordem Hypocreales), são comumente encontrados em solo onde sobrevivem de maneira saprofítica ou como endofíticos do sistema radicular das plantas. Informações sobre a composição destas espécies bem como sua diversidade, distribuição e associação com diferentes tipos de cultivos e vegetação nativa são escassas no Brasil. O presente estudo foi desenvolvido para comparar a abundância de fungos entomopatogênicos e a diversidade genética de isolados de Metarhizium spp. em amostras de solo de cultivos anuais, perenes e vegetação nativa, em cinco estados brasileiros que representam os biomas Amazônia, Cerrado, Caatinga, Mata Atlântica e Pampa, em duas estações (seca e úmida) nos anos de 2012 e 2013. O isolamento dos fungos foi realizado com meio seletivo e \"Insect bait\" utilizando Galleria mellonella e Tenebrio molitor. Nos estudos de diversidade genética de Metarhizium spp. foram utilizadas sequências de DNA da região MzIGS3. Representantes dos haplótipos revelados nesta análise tiveram a região 5\'-TEF sequenciada para identificação específica. Fungos entomopatogênicos foram isolados de 86% das 1.056 amostras de solo sendo Metarhizium o gênero predominante (66% das amostras de solo), seguido por Beauveria (41,9%) e Isaria (10,8%). Em geral, as maiores densidades de fungos entomopatogênicos foram obtidas nos biomas Amazônia e Cerrado e as menores densidades detectadas no bioma Caatinga. Metarhizium spp. foi detectado em maior número de amostras de solo em vegetação nativa e cultivos anual e perene do Cerrado. A frequência de Isaria spp. foi baixa nas amostras de solo, sendo detectado em maior número de amostras nos solos com cultivos anuais e vegetação nativa na Amazônia e Caatinga. Metarhizium spp. foi geralmente encontrado em um maior número de amostras coletadas na estação úmida em comparação com as coletas da estação seca, por outro lado Beauveria spp. foi superior na estação seca. A diversidade dos isolados de Metarhizium spp. provenientes de áreas de vegetação nativa foi maior do que dos isolados de cultivos anuais e perenes. Seis linhagens foram encontradas neste estudo; M. robertsii, M. anisopliae, M. pingshaense e três espécies indeterminadas. M. robertsii foi a linhagem predominante (65% dos isolados) sendo encontrado em áreas com vegetação nativa e cultivos anual e perene dos cinco biomas. Metarhizium sp. indet. 1 apresentou a maior diversidade haplotípica dentre as linhagens estudadas. Uma nova linhagem, não caracterizada taxonomicamente, Metarhizium sp. indet. 3, foi encontrada predominantemente na Caatinga. Somente na Amazônia foram encontradas todas as linhagens. O conhecimento da composição das populações de fungos entomopatogênicos nativos bem como sobre a filogenia, diversidade e distribuição dos haplótipos de Metarhizium spp. em solos brasileiros, gerado neste estudo, poderá servir como subsídio para o desenvolvimento de estratégias de conservação e maximização do controle biológico natural de pragas. / Entomopathogenic fungi of the genera Metarhizium, Beauveria and Isaria (order Hypocreales) are associated to the soil where they survive saprofitically or as endophytes of the plants root system. Information on the species composition and its diversity, distribution and association of these fungi with different types of crops and native vegetation are scarce in Brazil. The present study was carried out to compare the abundance of entomopathogenic fungi and the genetic diversity of Metarhizium spp. Isolated from soil samples from annual and perennial crops and native vegetation in five Brazilian states that represent the biomes Amazon, Cerrado, Caatinga, Atlantic Forest and Pampa, in two seasons (wet and dry) in the years 2012 and 2013. The isolation of fungi was performed with selective medium and \"Insect bait\" using Galleria mellonella and Tenebrio molitor. DNA sequences of the region MzIGS3 were used in genetic diversity studies of Metarhizium spp. Representatives haplotypes revealed in the diversity analysis had the 5\'-TEF region sequenced for species identification. Entomopathogenic fungi were isolated from 86% of 1,056 soil samples and Metarhizium was the predominant genus (66% of soil samples), followed by Beauveria (41.9%) and Isaria (10.8%). In general, the highest densities of entomopathogenic fungi were obtained in the Amazon and Cerrado biomes and the lowest densities were detected in the Caatinga biome. Metarhizium spp. was detected in a greater number of soil samples from native vegetation and annual and perennial crops of Cerrado. The frequency of Isaria spp. was low in soil samples being detected in a greater number of soils with annual crops and native vegetation in the Amazon and Caatinga. Metarhizium spp. was usually found in a greater number of samples collected during the wet season compared to the collections in the dry season. On the other hand, Beauveria spp. was higher in the dry season. The diversity of isolates of Metarhizium spp. from areas of native vegetation was greater than that obtained from annual and perennial crops. Six lineages were found in this study; M. robertsii, M. anisopliae, M. pingshaense and three indeterminate species. M. robertsii was the predominant (65% of isolates) found in areas with native vegetation and in the annual and perennial crops of the five biomes. Metarhizium sp. indet. 1 showed the greatest haplotype diversity among the strains studied. A new strain, not characterized taxonomically, Metarhizium sp. indet. 3, was found predominantly in the Caatinga. Only in the Amazon, all lineages were found. The knowledge on species composition of entomopathogenic fungi as well as about phylogeny, diversity and distribution of haplotypes of Metarhizium spp. in Brazilian soils, generated in this study, may be useful for the development of strategies for conservation and maximization of natural biological control of pests.
22

[en] ANALYSIS OF FOREST FRAGMENTS AND THE NATIVE VEGETATION PROTECTION LAW: THE MUNICIPALITY OF SILVA JARDIM, RJ / [pt] ANÁLISE DA FRAGMENTAÇÃO FLORESTAL E A LEI DE PROTEÇÃO DA VEGETAÇÃO NATIVA: O MUNICÍPIO DE SILVA JARDIM, RJ

THAIS GULIAS OLIVEIRA 22 December 2020 (has links)
[pt] O município de Silva Jardim cuja região possui uma rica biodiversidade tanto em flora, quanto fauna, em seu bioma fragmentado. Um dos aliados para o processo de conservação dos biomas são as leis implementadas pelo Lei de Proteção da Vegetação Nativa, pois, visa proteger principalmente as áreas mais frágeis e de extrema importância para a recuperação da paisagem. Nesse sentido essa dissertação teve por objetivo avaliar o potencial de conservação a partir da integração da análise dos fragmentos florestais e da Lei de Proteção da Vegetação Nativa- LPVN. Para isso, a metodologia se debruçou em levantado todo o processo histórico de ocupação do município. Espacializar a LPVN através de técnicas de geoprocessamento em ambiente SIG. Utilizando os princípios da ecologia da paisagem, se escolheu as métricas de paisagem para avaliação dos fragmentos no software V-Late, podendo assim caracterizar o cenário atual. Tivemos como resultado 33,2 porcento do total de Silva Jardim protegidos pela LPVN. Os fragmentos muito pequenos e grandes foram os que mais chamaram atenção na análise final, tendo 45 porcento de suas áreas protegidas, devido a sua distribuição pela paisagem. Finalmente, quando analisamos a eficiência da LPNV, não podemos anular o processo de ocupação, dado que as áreas mais fragmentadas estão nos limites de APP de curso d água em áreas planas. Sendo assim, é preciso pensar em planos de educação e conscientização da população para a conservação da Mata Atlântica. / [en] The municipality of Silva Jardim, whose region has a rich biodiversity in both flora and fauna, in its fragmented biome. One of the allies for the conservation process of the biomes are the laws implemented by the Native Vegetation Protection Law because it aims to protect mainly the most fragile areas and of extreme importance for the recovery of the landscape. In this sense, this dissertation aimed to evaluate the conservation potential based on the integration of forest fragment analysis and the Native Vegetation Protection Law (Law 12.651 / 12). For that, the methodology looked at the entire historical occupation process of the county. Specialize Native Vegetation Protection Law through geoprocessing techniques in a GIS environment. Using the principles of landscape ecology, were chosen the landscape metrics to assess fragments in the V-Late software, thus being able to characterize the current scenery. As a result, 33.2 percent of Silva Jardim s total was protected by the Native Vegetation Protection Law. The very small and large fragments were the ones that attracted the most attention in the final analysis, with 45 percent of their areas protected, due to their distribution across the landscape. Finally, when we analyze the efficiency of Native Vegetation Protection Law, we cannot cancel the occupation process, given that the most fragmented areas are within the limits of permanent preservation watercourse sector in flat territories. Therefore, it is necessary to think about education and awareness plans for the conservation of the Atlantic Forest.
23

“Ghost fields” in the Brazilian Pampa: inventory of abandoned eucalyptus plantations due to remaining tree stumps – resource gambling in a fragile biome with a history of massive land conversion

Potter Thomsen, Lars January 2024 (has links)
The main objective of this study was to make an inventory of abandoned eucalyptus plantations due to remaining tree stumps in the Brazilian Pampa biome, focusing on the two counties Pedras Altas and Candiota. In the study, the term “ghost fields” was used for abandoned eucalyptus plantations – land areas that were previously planted with eucalyptus and subsequently left unproductive for a number of years, no longer used for eucalyptus and not converted into e.g. pasture or soybean plantation. After three successive rotations, typically every 21 years, eucalyptus land needs to be processed mechanically to remove remaining stumps and allow new plantation, but stump clearing is costly, and in some cases, non-industrial owners leave the fields ghosted. More than half of the native vegetation, primarily grassland, in the Pampa has been converted into agriculture and forestry, and eucalyptus species are especially popular for plantation because of speedy growth and adaptability to harsh conditions. The loss of native grasslands to continuous short-rotation eucalyptus plantation for commercial use has resulted in soil degradation and biodiversity loss. The demand for productive land, and importance of conserving native vegetation, made it relevant to investigate the extent of ghost fields and the correlation between suppressed native vegetation and ghost fields and between suppressed native vegetation and eucalyptus plantation in general. The study showed that 11 percent (2,727 out of 24,746 hectares) of eucalyptus plantation in the focus area, comprising Pedras Altas and Candiota County, was ghosted for a period of 1-11 years between 2012-2023. Based on extrapolation of the findings in the focus area, 26,323 hectares (11 percent) out of the total 239,297 hectares of eucalyptus plantation in the Pampa may have been ghosted for a number of years between 2012-2023 because of remaining tree stumps. 500 (out of 980) hectares of ghost fields in Pedras Altas County and 543 (out of 1747) hectares of ghost fields in Candiota County were connected to areas with recent suppression of native vegetation (2004-2022). 8,240 (out of 13,200) hectares of eucalyptus plantation, including ghost fields, in Pedras Altas County and 4,829 (out of 11,546) hectares of eucalyptus plantation, including ghost fields, in Candiota County were connected to areas with recent suppression of native vegetation.

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