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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

Padrões de organização das assembleias de aves florestais em uma paisagem fragmentada de Floresta Atlântica

Oliveira, Renan Campos de 27 April 2015 (has links)
CAPES / O Brasil abriga uma das mais ricas avifaunas do mundo, a qual está submetida a altos índices de degradação ambiental, principalmente no que se refere à fragmentação florestal. O bioma Floresta Atlântica retrata esse histórico de devastação e hoje remanesce em paisagens altamente degradadas na forma de pequenos fragmentos isolados. Este projeto teve por objetivo avaliar os efeitos da fragmentação florestal em uma área com remanescentes de Floresta Atlântica no norte do Paraná (Brasil) sobre a distribuição e a organização da assembleia de aves florestais, testando a hipótese de que a organização da assembleia nos fragmentos é diferente daquela esperada ao acaso. Realizamos quatro amostragens qualitativas da avifauna em três conjuntos de fragmentos florestais na paisagem, cada um com três fragmentos cada: grande, médio e pequeno. Foram duas amostragens entre setembro e novembro/2013 e duas entre março e maio/2014. Em cada amostragem foi aplicado o método de pontos de escuta ao longo de transectos percorridos aleatoriamente, com um esforço amostral de dois dias de observação por fragmento e duas réplicas diárias (6h30 às 10h30 e 15h00 às 19h00), respeitando os horários de maior atividade das aves. A estrutura da assembleia foi avaliada por índices de coocorrência de espécies (Checkerboard e CScore) e padrões de diversidade α (riqueza) e β (turnover de espécies), enquanto a estrutura da paisagem foi analisada a partir dos parâmetros: área, distância entre os fragmentos, dimensão fractal, densidade de borda, índice de forma do fragmento e índice de área nuclear. A hipótese nula de ausência de estrutura na assembleia de aves na paisagem foi testada com modelos nulos a partir dos índices de coocorrência. Os efeitos da estrutura da paisagem sobre a estrutura da assembleia foram analisados pelo teste de Mantel e análise de componentes principais (PCA). A estrutura da assembleia na paisagem apresentou um padrão de organização espaço-temporal significativamente diferente daquele esperado ao acaso, revelando uma estruturação mais influenciada pela segregação entre as espécies. Os fragmentos apresentaram diferenças significativas quanto à riqueza, ao contrário dos conjuntos de fragmentos, indicando relativa homogeneidade na estrutura da paisagem. As diferenças entre os tamanhos e a distância entre os fragmentos influenciaram significativamente os padrões de organização da assembleia de aves florestais na paisagem e os padrões de diversidades α e β, indicando que quanto maiores os fragmentos e menores as distâncias entre eles, mais o padrão de coocorrência entre as espécies é diferente do esperado ao acaso. A partir dos resultados encontrados foi possível inferir que a paisagem fragmentada de remanescentes de Floresta Atlântica do norte do Paraná ainda apresenta disponibilidade de recursos ambientais e características físicas que permitem a persistência de uma estrutura de organização da assembleia de aves florestais no espaço ao longo do tempo. / Brazil is home to one of the richest avifaunas the world, which is subject to high levels of environmental degradation, in particular forest fragmentation. The Atlantic Forest biome depicts this history of devastation and today remains as small isolated fragments on highly degraded landscapes. This project aimed to evaluate the effects of forest fragmentation in an area with Atlantic Forest remnants in northern Paraná (Brazil) on the distribution and the organization of assemblage of forest birds and tested the hypothesis that the structure of the assembly in the fragments is different than expected by chance. We did four qualitative samplings of birds in three sets of forest fragments in the landscape, each with three fragments: large, medium and small. The method applied in the sampling was point counts along transects, traveled randomly for four hours in each fragment. Samples were taken in two periods: from September to November / 2013, and between March and May / 2014. The structure of the meeting was assessed by rates of co-occurring species (Checkerboard and CScore) and α diversity patterns (wealth) and β (turnover of species), while the landscape structure was analyzed from the parameters: area, distance between fragments, fractal dimension, edge density, fragment shape index and nuclear area index. The null hypothesis of no structure in the assembly of birds in the landscape was tested with null models from the co-occurrence indexes. The effects of landscape structure on the assembly of the structure were analyzed by the Mantel test and principal component analysis (PCA). The assembly of the structure in the landscape showed a pattern of spatiotemporal organization significantly different from that expected by chance, revealing a structure most influenced by segregation of the species. The fragments showed significant differences in richness, unlike sets of fragments, indicating relative homogeneity in the landscape structure. The differences between the size and the distance between the fragments significantly influenced the patterns of organization of the meeting of forest birds in the landscape and patterns of α and β diversity, indicating that the higher the fragment and smaller distances between them, more the standard of species cooccurrence is different than expected by chance. Thus, the fragmented landscape of remnants of the northern Paraná Atlantic Forest still has availability of environmental resources and physical characteristics that allow a persistent organizational structure of the assembly of forest birds in space over time.
62

Dinâmica da fragmentação florestal e conflito de uso do solo ao longo da rede de drenagem do município de Lençóis Paulista - SP / Dynamics of the forest fragmentation and conflict in the use of the land along the drainage network of the city of Lençois Paulista

Mileski, Milena Montanholi [UNESP] 25 May 2015 (has links) (PDF)
Made available in DSpace on 2015-12-10T14:24:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-05-25. Added 1 bitstream(s) on 2015-12-10T14:30:32Z : No. of bitstreams: 1 000851964.pdf: 1312054 bytes, checksum: 6ab2821ce3b046bbbd11abc30329b215 (MD5) / A partir da década de 1950, a população mundial cresceu rapidamente, atingindo hoje mais de 7 bilhões de habitantes, gerando assim o aumento do processo de urbanização. Para atender a demanda de bens de consumo duráveis e não duráveis da atual população, a economia agropecuária expandiu e, consequentemente ampliou suas fronteiras. Com isso, áreas destinadas à cultura agrícola e pastagem ocuparam espaços em que, anteriormente eram ocupados por matas ciliares e florestas nativas; ocasionando a redução ou inexistência da vegetação que circunda as redes de drenagem e fragmentação das florestas. Nesse contexto, a análise do uso e ocupação do solo de Lençóis Paulista, através da utilização de Sistemas de Informações Geográficas e imagens do satélite Landsat, se torna necessária pois as principais empresas geradoras de emprego do município dependem diretamente da matéria- prima rural, como cana de açúcar e eucalipto, presentes em cerca de 80% do território do município. / Since the decade of 1950, the world population has dramatically increased, reaching nowadays around 7 billion people, which has caused an increase in the urbanization process. In order to supply the people's demand for durable and non-durable goods, there was an expansion in the agriculture economy, which has as a consequence the expansion of its frontiers. Areas for agricultural activities and pasture have used lands which had been previously characterized by riparian and native forests, resulting in the reduction or even inexistence of vegetation around the drainage network and forest fragmentation. In this context, the analysis of the use and occupation of the land of LençóisPaulista, by means of the use of Geographical Information Systems and images generated by Landsat satellites, is necessary, since the main companies employing people in the city directly depend on rural goods, such as sugar cane and eucalyptus, cultures present in approximately 80% of the city's territory.
63

Estudo da cobertura vegetal nativa da bacia do rio Ocoy, oeste do Paraná: subsídios para a implantação de um corredor de biodiversidade entre o Parque Nacional do Iguaçu e o Lago de Itaipu

Seganfredo, Diogo 27 March 2015 (has links)
Este estudo objetivou avaliar aspectos da estrutura da paisagem relacionados à conservação da biodiversidade em uma microbacia situada em região de importância estratégica para a implantação do Corredor de Biodiversidade do Rio Paraná. Os mapas foram elaborados a partir de imagens de satélite e manipuladas no software de geoprocessamento Spring. A partir do mapa de uso e cobertura do solo gerou-se 4 diferentes cenários: situação real (vegetação atual), considerando efeito de borda (faixa de 50 m entorno dos fragmentos como borda), sem as Áreas de Preservação Permanente – APP (desconsiderou-se a existência das APPs) e o cenário com a restauração de todas as APPs (de acordo com a legislação vigente). Com base em métricas da paisagem analisou-se os resultados do uso e cobertura da terra e dos demais cenários. Os resultados indicaram que o uso predominante é agricultura e 24,6% da área total estudada é composta por vegetação natural, sendo que o maior remanescente possui 315,3 ha. As APPs ocupam 3,1% da área de estudo e 75% dessas áreas estão cobertas com cobertura vegetal natural. Os outros 25% restantes da APP encontram-se sem vegetação. Os resultados mostraram que ao considerar o efeito de borda nos remanescentes restaram apenas 28% como área central, no cenário em que se desconsiderou a presença das APPs gerou-se grande impacto na fragmentação, com diminuição na área da classe e aumento no número de fragmentos. No cenário que se considerou a restauração de APPs faltantes promoveu-se aumento na conectividade efetiva da paisagem, a partir dos resultados do índice de PROX. Desta forma, concluiu-se que as APPs possuem papel fundamental na conectividade de fragmentos florestais. A avaliação dos cenários mostrou que ações de restauração com abrangência espacial restrita em áreas de preservação permanente podem resultar em um expressivo aumento da conectividade da paisagem. / This study aimed to evaluate features of landscape structure related to the conservation of biodiversity in a watershed located in strategically important region for the implementation of the Paraná River Biodiversity Corridor. The maps were made from satellite images and manipulated in the Spring GIS software. From the land use and land cover map 4 different scenarios were generated: real situation (current vegetation), considering edge effect (50 m surrounding the fragments as edge), without the Permanent Preservation Areas - PPA (dismissed the existence of the PPAs) and the scenario with the restoration of all PPAs (according to the Brazilian Forest Code). Based on landscape metrics the results of the land use and land cover and other scenarios were analyzed. The results indicated that the predominant land use is agriculture and 24.6% of the total study area consists of natural vegetation, and the largest remnant has 315.3 ha. The PPAs occupy 3.1% of the study area and 75% of these areas are covered with natural vegetation. The other remaining 25% of PPA have no vegetation. The results showed that when the edge effect in the remnants was considered it remained only 28% as the central area; in the scenario that the presence of PPAs was disregarded it was generated a great impact in fragmentation, with a decrease in the area of class and increase in the number of fragments. In the scenario that considered the missing PPAs restoration it was promoted an increase in the effective connectivity of the landscape, from the results of the PROX index. Thus, PPA have a fundamental function in connecting forest fragments. The evaluation of the scenarios showed that the restoration of small areas of PPAs, according to the Brazilian Forest Code, could generate strong benefits for the landscape connectivity.
64

Estudo da cobertura vegetal nativa da bacia do rio Ocoy, oeste do Paraná: subsídios para a implantação de um corredor de biodiversidade entre o Parque Nacional do Iguaçu e o Lago de Itaipu

Seganfredo, Diogo 27 March 2015 (has links)
Este estudo objetivou avaliar aspectos da estrutura da paisagem relacionados à conservação da biodiversidade em uma microbacia situada em região de importância estratégica para a implantação do Corredor de Biodiversidade do Rio Paraná. Os mapas foram elaborados a partir de imagens de satélite e manipuladas no software de geoprocessamento Spring. A partir do mapa de uso e cobertura do solo gerou-se 4 diferentes cenários: situação real (vegetação atual), considerando efeito de borda (faixa de 50 m entorno dos fragmentos como borda), sem as Áreas de Preservação Permanente – APP (desconsiderou-se a existência das APPs) e o cenário com a restauração de todas as APPs (de acordo com a legislação vigente). Com base em métricas da paisagem analisou-se os resultados do uso e cobertura da terra e dos demais cenários. Os resultados indicaram que o uso predominante é agricultura e 24,6% da área total estudada é composta por vegetação natural, sendo que o maior remanescente possui 315,3 ha. As APPs ocupam 3,1% da área de estudo e 75% dessas áreas estão cobertas com cobertura vegetal natural. Os outros 25% restantes da APP encontram-se sem vegetação. Os resultados mostraram que ao considerar o efeito de borda nos remanescentes restaram apenas 28% como área central, no cenário em que se desconsiderou a presença das APPs gerou-se grande impacto na fragmentação, com diminuição na área da classe e aumento no número de fragmentos. No cenário que se considerou a restauração de APPs faltantes promoveu-se aumento na conectividade efetiva da paisagem, a partir dos resultados do índice de PROX. Desta forma, concluiu-se que as APPs possuem papel fundamental na conectividade de fragmentos florestais. A avaliação dos cenários mostrou que ações de restauração com abrangência espacial restrita em áreas de preservação permanente podem resultar em um expressivo aumento da conectividade da paisagem. / This study aimed to evaluate features of landscape structure related to the conservation of biodiversity in a watershed located in strategically important region for the implementation of the Paraná River Biodiversity Corridor. The maps were made from satellite images and manipulated in the Spring GIS software. From the land use and land cover map 4 different scenarios were generated: real situation (current vegetation), considering edge effect (50 m surrounding the fragments as edge), without the Permanent Preservation Areas - PPA (dismissed the existence of the PPAs) and the scenario with the restoration of all PPAs (according to the Brazilian Forest Code). Based on landscape metrics the results of the land use and land cover and other scenarios were analyzed. The results indicated that the predominant land use is agriculture and 24.6% of the total study area consists of natural vegetation, and the largest remnant has 315.3 ha. The PPAs occupy 3.1% of the study area and 75% of these areas are covered with natural vegetation. The other remaining 25% of PPA have no vegetation. The results showed that when the edge effect in the remnants was considered it remained only 28% as the central area; in the scenario that the presence of PPAs was disregarded it was generated a great impact in fragmentation, with a decrease in the area of class and increase in the number of fragments. In the scenario that considered the missing PPAs restoration it was promoted an increase in the effective connectivity of the landscape, from the results of the PROX index. Thus, PPA have a fundamental function in connecting forest fragments. The evaluation of the scenarios showed that the restoration of small areas of PPAs, according to the Brazilian Forest Code, could generate strong benefits for the landscape connectivity.
65

Guenon Hybridization and Its Effects on Parasite Infection in Gombe National Park, Tanzania

Unknown Date (has links)
Fecal samples were obtained from guenons in Gombe National Park utilizing noninvasive, opportunistic sampling techniques. Samples were then examined for the presence of gastrointestinal parasites using chlorazol black stain, Lugol’s iodine staining, as well as concentration via fecal flotation with Sheather’s sugar solution. Results were analyzed using SPSS (IBM corp), and compared to other forested regions in Africa to determine whether hybridization influences parasite prevalence of these guenons living in Gombe; and if these guenons differ from similar guenons in other regions of Africa. The null hypothesis was unable to be rejected in all cases; hybridization could not be stated as a contributing factor for differences found in parasitic prevalence rates. Furthermore, no statistical difference was found between Gombe’s guenons, and those living in other regions of Africa in most cases. The author suspects that the abundance of parasitic generalists discovered, small sample size, and opportunistic sampling protocol contribute to these finding. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection
66

Análise de custo-eficácia dos pagamentos por serviços ambientais em paisagens fragmentadas: estudo de caso de São Paulo / Cost-effectiveness analysis of payments for environmental services in fragmented landscapes: case study in the State of São Paulo

Fendrich, Arthur Nicolaus 14 November 2017 (has links)
Mesmo com o crescimento da dependência da vida humana em relação aos serviços ecossistêmicos, a taxa de perda de diversidade genética no planeta tem alcançado níveis semelhantes à de grandes eventos de extinção, evidenciando a necessidade de ações para a conservação dos recursos naturais. Em adição aos tradicionais instrumentos de comando e controle para a conservação, os instrumentos econômicos têm tido crescente atenção no mundo nos últimos anos, com especial destaque para os Pagamentos por Serviços Ambientais (PSA). A abordagem de pagamentos de incentivos tem crescido na última década e, apesar das potencialidades que o PSA apresenta, muitos programas falham em incorporar o conhecimento científico em sua execução, sendo esse um dos aspectos que podem acarretar baixo desempenho ambiental e econômico. Neste contexto, o presente projeto buscou avaliar a custo-eficácia do PSA em paisagens fragmentadas. A área de estudo é o estado de São Paulo, cuja fragmentação historicamente ocorre pela expansão agropecuária e pelos diversos impactos decorrentes do grande crescimento populacional em seu território. Foram distribuídos questionários para a obtenção das preferências dos proprietários rurais paulistas em relação aos programas de PSA para restauração de vegetação nativa. Os dados coletados foram relacionados a características socioeconômicas e ambientais e um modelo beta inflacionado de zero misto dentro da classe GAMLSS foi utilizado. Em seguida, o modelo foi utilizado para predizer os resultados para os proprietários não entrevistados e a curva de investimento para diferentes retornos para conservação foi construída. Os resultados apontaram que o PSA é uma alternativa muito custosa frente aos orçamentos ambientais paulistas e que traz poucos benefícios para a restauração no estado de São Paulo. A pesquisa possui uma vertente teórica, pois contribui para a compreensão da adequabilidade do PSA em paisagens fragmentadas, e uma vertente prática, pois explicita a quantidade de recursos necessária para a execução dos programas analisados. / Although the dependence of human activities on ecosystem services has risen in the past decades, the current rate of genetic diversity loss has substantially declined and reached alarming levels. In addition to the traditional command and control approach for the promotion of conservation, growing attention has been given to economic instruments, especially to Payments for Environmental Services (PES). Despite all potentialities of the PES instrument, many programs fail to introduce scientic knowledge in the execution. Such a lack of foundation may result in low environmental and economic performance. The present research aims at evaluating the cost-effectiveness of PES in fragmented landscapes. The study area is the state of São Paulo, which has been fragmented by the agricultural and pasture expansion, and the impacts linked to the large population growth. A survey with dierent PES programs was sent to rural landowners and responses were analyzed and linked to socioeconomic and environmental characteristics through a zero-inflated beta mixed model, within the GAMLSS framework. The model was used to predict enrollment of non-respondents in different PES programs. Finally, the relationship between total area for restoration and the amount of resources needed for each program was compared to the environmental budget of the state of São Paulo. Results show that PES is a very costly alternative that can provide only few results for restoration. The present work has a theoretical orientation, as it contributes to the comprehension of the feasibility of PES programs in fragmented landscapes, and a practical orientation, as it quantifies the amount of resources required by the programs analyzed.
67

Settlement formation and land cover and land use change a case study in the Brazilian Amazon /

Caldas, Marcellus Marques. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Geography, 2008. / Title from PDF t.p. (viewed on July 22, 2009) Includes bibliographical references (p. 228-249). Also issued in print.
68

Butterfly movements among isolated prairie patches habitat edge, isolation, and forest-matrix effects /

Stasek, David Jon. January 2006 (has links)
Thesis (M.S.)--Miami University, Dept. of Zoology, 2006. / Title from first page of PDF document. Includes bibliographical references.
69

Relação da estrutura da paisagem mosaico Carajás, PA com a ocorrência de Anodorlynchus hyacinthinus (arara-azul-grade) / Relationship between landscape structure mOSaIC Carajás, PA with the occurrence of Anodorhynchus hyacinthinus (Hyacinth macaw)

Conrado, Ludmila Pereira 04 September 2015 (has links)
Submitted by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T19:24:51Z No. of bitstreams: 1 CONRADO_Ludmila Pereira_2016.pdf: 10153126 bytes, checksum: f7c09775254235adf2760cfd25fb8a1b (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T19:25:04Z (GMT) No. of bitstreams: 1 CONRADO_Ludmila Pereira_2016.pdf: 10153126 bytes, checksum: f7c09775254235adf2760cfd25fb8a1b (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T19:25:12Z (GMT) No. of bitstreams: 1 CONRADO_Ludmila Pereira_2016.pdf: 10153126 bytes, checksum: f7c09775254235adf2760cfd25fb8a1b (MD5) / Made available in DSpace on 2017-01-12T19:25:20Z (GMT). No. of bitstreams: 1 CONRADO_Ludmila Pereira_2016.pdf: 10153126 bytes, checksum: f7c09775254235adf2760cfd25fb8a1b (MD5) Previous issue date: 2015-09-04 / Não recebi financiamento / In Brazil, there are about 6,500 individuals of Anodorhynchus hyacinthinus (Hyacinth macaw) in wild, located in three physiognomically distinct regions. The specie is demanding as to breeding habitat, and can be regarded as feeding specialist. Currently, the species is endangered because the reduction of their originally habitat, as consequence of the disorderly process of land occupation. This process, broadly, causes negative effects on landscape, in particular the remaining native forest vegetation. In this context, the study aimed to evaluate the occurrence of Hyacinth macaw in mosaic Carajás landscape, considering the intrinsic characteristics of the landscape structure and biology of this species. We considered three regions of the Carajás mosaic: R1- Itacaiúnas river, R2-FLONA Itacaiúnas and, R3 - Canaã dos Carajás. The sampling of Hyacinth macaw was done through direct observation and calculated the frequency records for R1 (1.26 region/hour), R2 (0.38 reg./hour) and R3 (0.44 reg. /hour), and after, was estimated area of life for each region (R1 = 22187.87 ha; R2= 66397.0ha, R3 = 41841.2ha). We made the land-use/land-cover map to support evaluation of the landscape, through unsupervised classification of satellite images. The final map was reclassified two classes: forest and non-forest. The follow landscape metrics were calculated: distance between fragments (R2 = 499 m; R3 = 364m), midsize (R2 = 148,5ha; R3 = 10,6ha), the size of the largest fragment (R2 = 39.360,8ha; R3 = 888,1ha), and number of fragments (R2 = 337, R3 = 863). From the results, we can said that forested areas with riparian vegetation presence appear to be more propitious to Hyacinth macaw occurrence in the mosaic Carajás, Pará, Brazil, but the preference for open areas is not ruled out. Furthermore, the species occupy different degraded patterns landscape, because there is a large displacement capacity and proximity to the mosaic. Atropism and interaction with other species, such as red macaws may be other factors that affect the distribution of species in the Carajás region. / No Brasil, estima-se um total de 6.500 indivíduos de Anodorhynchus hyacinthinus (araraazul-grande) em vida livre, distribuídos em três regiões fisionomicamente distintas. A espécie é exigente quanto ao seu hábitat reprodutivo, e pode ser considerada especialista quanto à alimentação. Encontra-se, atualmente, ameaçada de extinção em função da redução de seu habitat natural, por consequência do processo desordenado de uso e ocupação do solo. Este processo, por sua vez, acarreta efeitos negativos na paisagem como um todo e, em especial nos remanescentes de vegetação florestal nativa. Nesse contexto, o trabalho teve como objetivo avaliar a ocorrência da arara-azul-grande, na paisagem do mosaico Carajás, considerando as características intrínsecas da estrutura da paisagem e a biologia da espécie. Considerou-se para o estudo, três regiões do mosaico Carajás: R1- rio Itacaiúnas, R2- FLONA Itacaiúnas, R3- Canaã dos Carajás. Para a amostragem da arara-azul-grande foi feita observação direta e calculou-se a frequência de avistamentos para R1 (1,26 reg./hora), R2 (0,38reg./hora) e R3 (0,44 reg./hora), posteriormente foi estimada a área de vida da espécie em cada região (R1= 22.187,87 ha; R2= 66.397,0ha; R3= 41.841,2ha). Para subsidiar a avaliação da paisagem foi feito o mapa de uso e cobertura do solo, através da classificação não supervisionada de imagens orbitais, sendo que as classes resultantes foram reclassificadas em floresta e não floresta. As métricas da paisagem calculadas foram: distância entre fragmentos (R2= 499 m; R3=364m), tamanho médio (R2=148,5ha; R3= 10,6ha), tamanho do maior fragmento (R2= 39.360,8ha; R3=888,1ha) e número de fragmentos (R2= 337; R3=863). A partir dos resultados obtidos pode-se dizer que as áreas florestadas, com presença de mata ciliar, parecem ser um ambiente mais propicio à ocorrência da arara-azul-grande no mosaico Carajás/PA, porém a preferência por áreas abertas não é descartada. Além disso, os indivíduos da espécie ocupam diferentes padrões de paisagem degradada, devido sua ampla capacidade de deslocamento e proximidade com o mosaico. Entre outros fatores que podem afetar sua ocorrência na região de Carajás, pode-se citar a antropização e interação com outras espécies, como a arara-vermelha.
70

Monitoring carbon stocks in the sub-tropical thicket biome using remote sensing and GIS techniques : the case of the Great Fish River Nature Reserve and its environs, Eastern Cape province, South Africa

Nyamugama, Adolph January 2013 (has links)
The subtropical thicket biome in the Eastern Cape Province of South Africa has been heavily degraded and transformed due overutilization during the last century. The highly degraded and transformed areas exhibit a significant loss of above ground carbon stocks (AGC) and loss of SOC content. Information about land use /cover change and fragmentation dynamics is a prerequisite for measuring carbon stock changes. The main aim of this study is to assess the trends of land use/cover change, fragmentation dynamics, model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, quantify and map the spatial distribution of SOC concentrations in the partial subtropical thicket cover in the Great Fish River Nature Reserve and environs (communal rangelands). Multi-temporal analyses based on 1972 Landsat MSS, 1982 and 1992 Landsat TM, 2002 Landsat ETM and 2010 SPOT 5 High Resolution images were used for land use/cover change detection and fragmentation analysis. Object oriented post-classification comparison was applied for land use/cover change detection analysis. Fragmentation dynamics analysis was carried out by computing and analyzing landscape metrics in land use/cover classes. Landscape fragmentation analyses revealed that thicket vegetation has increasingly become fragmented, characterized by smaller less linked patches of intact thicket cover. Landscape metrics for intact thicket and degraded thicket classes reflected fragmentation, as illustrated by the increase in the Number of Patches (NP), Patch Density (PD), Landscape Shape Index (LSI), and a decrease in Mean Patch Size (MPS). The use of remote sensing techniques and landscape metrics was vital for the understanding of the dynamics of land use/cover change and fragmentation. Baseline land use/cover maps produced for 1972, 1982, 1992 2002 and 2010 and fragmentation analyses were then used for analyzing carbon stock changes in the study area. To model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, a method based on the integration of RS and GIS was employed for the estimation of AGC stocks in a time series. A non-linear regression model was developed using NDVI values generated from SPOT 5 HRG satellite imagery of 2010 as the independent variable and AGC stock estimates from field plots as the dependent variable. The regression model was used to estimate AGC stocks for the entire study area on the 2010 SPOT 5 HRG and also extrapolated to the 1972 Landsat MSS, 1982 and 1992 Landsat TM, and 2002 Landsat ETM. The AGC stocks for the period 1972 -1982, 1982-1992, 1992-200) and 2002-2010 were compared by means of change detection analysis. The comparison of AGC stocks was carried out at subtropical thicket class level. The results showed a decline of AGC stocks in all the classes from 1972 to 2010. Degraded and transformed thicket classes had the highest AGC stock losses. The decline of AGC stocks was attributed to thicket transformation and degradation which were caused by anthropogenic activities. To map and quantify SOC concentration in partial (fractional) thicket vegetation cover, the spectral reflectance of both thicket vegetation and bare-soils was measured in situ. Soil samples were collected from the sampling sites and transported to the laboratory for spectral reflectance and SOC measurements. Thicket vegetation and bare soil reflectance were measured using spectroscopy both in situ and under laboratory conditions. Their respective endmembers were extracted from ASTER imagery using the Pixel Purity Index (PPI). The endmembers were validated with in situ and laboratory thicket and bare-soil reflectance signatures. The spectral unmixing technique was applied to ASTER imagery to discriminate pure pixels of thicket vegetation and bare-soils; a residual spectral image was produced. The Residual Spectral Unmixing (RSU) procedure was applied to the residual spectral image to produce an RSU soil spectrum image. Partial Least Squares Regression (PSLR) model was developed using spectral signatures of a residual soil spectrum image as the independent variable and SOC concentration measured from soil samples as the dependent variable. The PSLR prediction model was used to predict SOC concentration on the RSU soil spectral image. The predicted SOC concentration was then validated with SOC concentration measured from the field plots. A Strong correlation (R2 = 0.82) was obtained between the predicted SOC concentration and the SOC concentration measured from field samples. The PSLR was then used to generate a map of SOC concentration for the Great Fish River Nature Reserve and its environs. Areas with very low SOC concentrations were found in the degraded communal villages, as opposed to the higher SOC values in the protected area. The results confirmed that RS techniques are key to estimating and mapping the spatial distribution of SOC concentration in partial subtropical thicket vegetation. Partial thicket vegetation has a huge influence on the soil spectra; it can influence the prediction of SOC concentration. The use of the RSU approach eliminates partial thicket vegetation cover from bare soil spectra. The residual soil spectrum image contains enough information for the mapping of SOC concentration. The technique has the potential to augment the applicability of airborne imaging spectroscopy for soil studies in the sub-tropical thicket biome and similar environments.

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