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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.
111

Atributos florais e reprodutivos de syagrus coronata (mart) becc. como ferramentas para a conservação de uma palmeira endêmica do Brasil

BARBOSA, Camila Miranda 24 February 2016 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2017-03-30T17:49:38Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Camila Miranda Barbosa.pdf: 2266282 bytes, checksum: 8e483f742cbf0b10a05321744d93decd (MD5) / Made available in DSpace on 2017-03-30T17:49:38Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Camila Miranda Barbosa.pdf: 2266282 bytes, checksum: 8e483f742cbf0b10a05321744d93decd (MD5) Previous issue date: 2016-02-24 / CNPQ / O licuri (Syagrus coronata) é uma palmeira que floresce e frutifica durante o ano inteiro, tendo grande importância ecológica e econômica, uma vez que fornece hábitat e alimento para diversos seres vivos, inclusive para a subsistência de populações humanas. Em populações nativas encontradas no Parque Nacional do Catimbau, a fenologia da espécie foi monitorada em quatro áreas (total de 120 indivíduos). Também foram identificados os visitantes florais, a composição química dos odores florais e a variação de temperatura das flores durante a antese, levando em consideração as fases reprodutivas (feminina e masculina), o sexo das estruturas reprodutivas (flores pistiladas e estaminadas) e o período do dia (manhã e noite). O fitness reprodutivo foi comparativamente analisado para polinização diurna vs noturna, entomófila vs anemófila. Amostras de odores florais foram coletadas através de “headspace” dinâmico a partir de flores pistiladas e estaminadas, bem como nas suas respectivas brácteas. O estudo da fenologia evidenciou duas áreas sazonais, enquanto duas outras produziram eventos contínuos de reprodução. A riqueza e abundância de visitantes florais foram maiores nas inflorescências masculinas que nas femininas. O fitness reprodutivo não mostrou diferença entre os tratamentos de polinização. Por sua vez, análises de odor floral demonstraram diferenças de compostos isolados nas brácteas e inflorescências, mas não entre as fases reprodutivas; a quantidade de odor emitido diferiu nas brácteas nas fases femininas e masculinas, mas não nas inflorescências, as quais apresentaram quantidades similares de compostos. Não foi evidenciado fenômeno de termogênese floral, nem ao longo do dia, nem entre as fases reprodutivas. Estratégias como o fornecimento de recursos em abundância e hábitat para visitantes florais, liberação diferenciada de odor e floração contínua, podem estar associadas à garantia do fluxo gênico dentro e entre populações dessa espécie de Syagrus. / Licuri (Syagrus coronata) is a palm tree that blooms and bears fruit throughout the year, having an ecological and economic importance, as it provides habitat and food for many living beings, including for the livelihoods of human populations. In native populations, found in Catimbau National Park, the phenology of species was monitored in four areas (total 120 individuals). Also flower visitors were identified, the chemical composition of floral scents and temperature variation of flowers at anthesis, taking into account the reproductive stages (male and female), sex of the reproductive structures (pistillate and staminate flowers) and the period the day (morning and evening). The reproductive fitness was comparatively analyzed for day vs. night pollinated and entomophilous vs anemophilus. Samples of floral odours were collected through "headspace" dynamic from pistillate and staminate flowers as well as in their respective bracts. The study of phenology showed two seasonal areas, while two others produced continuous reproductive events. The richness and abundance of floral visitors were higher in male than in female inflorescences. The reproductive fitness showed no difference between pollination treatments. In turn, floral odor analysis showed differences in isolated compounds in the bracts and flowers, but do not between the reproductive stage; the amount of odor emitted differed in the bracts in male and female phases, but not in inflorescences, which showed similar amounts of compounds. Floral thermogenesis phenomenon was not evidenced neither throughout the day nor between reproductive stages. Strategies such as providing abundant resources and habitat for floral visitors, differentiated release of odor and continuous flowering, may be associated with the guarantee of gene flow within and among populations of this species of Syagrus.
112

High diversity mixed plantations in Brazil: Eucalyptus intercropped with native tree species / Plantações mistas de alta diversidade no Brasil: Eucalyptus intercalado com espécies arbóreas nativas

Nino Tavares Amazonas 30 January 2018 (has links)
The high cost of restoring tropical forests is one of the greatest obstacle to achieving large-scale restoration. To overcome this barrier, we developed and implemented mixed plantations intercropping Eucalyptus with a high diversity of native tree species. The aim was to create favorable conditions for the regeneration of native species while simultaneously obtaining economic return from the exploitation of Eucalyptus as a commercial pioneer species. The use of Eucalyptus in this system is temporary and it shall be replaced by additional native species after it is harvested. In this research, we covered the main aspects and approaches of the effects of competition on tree growth using data from our restoration experiments. The objective of this research was to test the ecological viability of plantations that temporarily mix Eucalyptus spp. and a high diversity of native tree species during the initial phases of forest restoration as a strategy to offset implementation and maintenance costs. This alternative is investigated with a focus on the consequences of ecological interactions on tree survival and growth in three experiments implemented in the Atlantic Forest of Northeastern and Southeastern Brazil. We compared stands of native trees intercropped with Eucalyptus, traditional restoration plantations, and Eucalyptus monocultures. The thesis is structured in three main parts in which we focus in how the mixtures function compared to restoration plantations and Eucalyptus monocultures. We used forest inventories to understand the effects of competition and assessed ecophysiological parameters to provide insights about the mechanisms that affect tree growth when trees compete for water, light and nutrients. In the first part of the study, we showed that mixed plantations effectively combined high wood yield and tree diversity; that Eucalyptus grew larger in mixtures with native species than in monocultures; that native tree species grew less in mixtures with Eucalyptus; and that the mixing effect was stronger for fast- and intermediate-growing native species. In the second part, we found that mixtures consumed less water than monocultures; that Eucalyptus reduced the hydraulic performance of a fast-growing native species; and that tree growth was influenced by changes in the ecophysiology of water use. In the last part, we showed that a high diversity of nitrogen-fixing native trees facilitated Eucalyptus growth; that Eucalyptus had ~30% higher wood N concentration in mixtures; that native trees growth was not limited by nutrient competition with Eucalyptus; that Eucalyptus may benefit from increased light availability in mixed plantations; and that native species plots intercepted more sunlight than mixtures or Eucalyptus stands. This research has a strong interface between restoration science and practice, and contributed to the development of new ways to restore the tropical forests by allying restoration and production under the ecological and economic perspectives. Our findings indicate how to advance into the future, starting from the current state of art towards forest restoration systems that minimize competition and maximize growth, as an emergent promising alternative to finance tropical forest restoration and overcome the economic barrier that still holds large-scale restoration. This research may be used as a basis to continue adapting silviculture for different regions and forest ecosystems. Looking further into the future, these mixtures may also represent the starting point of a new silvicultural model that brings together production and conservation. The information available may be used by scientists, decision-makers, planners and restorationists to advance in the science and practice of restoration and silviculture in the tropics. / O alto custo de se restaurar as florestas tropicais são um dos maiores obstáculos para se atingir a restauração em larga escala. Para superar essa barreira, nós desenvolvemos e implantamos plantações mistas que intercalam Eucalyptus e uma alta diversidade de espécies arbóreas nativas. O objetivo é criar condições favoráveis para a regeneração das espécies nativas e, ao mesmo tempo, obter retorno econômico da exploração de eucalipto como uma espécie pioneira comercial. O uso do eucalipto nesse sistema é temporário e ele deve ser substituído por espécies nativa adicionais após ser colhido. Nessa pesquisa, nós cobrimos os principais aspectos e abordagens relacionados aos efeitos da competição sobre o crescimento arbóreo utilizando dados dos nossos experimentos. O objetivo dessa pesquisa foi testar a viabilidade ecológica de plantios que consorciam temporariamente eucalipto e uma alta diversidade de espécies arbóreas nativas durante as fases iniciais da restauração ecológica como uma estratégia para compensar parte dos custos de implantação e manutenção. Essa alternativa é investigada com foco nas consequências das interações ecológicas sobre a sobrevivência e o crescimento das árvores em três experimentos implantados na Mata Atlântica do nordeste e sudeste do Brasil. Nós implantamos e comparamos talhões de espécies nativas intercaladas com eucalipto, plantios de restauração tradicionais e monocultivos de eucalipto. A tese é estruturada em três partes principais com foco em como os plantios mistos funcionam em comparação a plantios de restauração e monocultivos de eucalipto. Nós utilizamos inventários florestais para entender os efeitos da competição e estimamos parâmetros ecofisiológicos para investigar os mecanismos que afetam o crescimento arbóreo quando as árvores competem por água, luz e nutrientes. Na primeira parte do estudo, nó mostramos que os plantios mistos combinaram efetivamente alta produção de madeira com diversidade arbórea; que eucalipto cresceu mais em plantios mistos do que em monocultivos; que espécies nativas cresceram menos em consórcio com eucalipto; e que o efeito do consórcio foi maior para espécies de crescimento rápido e intermediário. Na segunda parte, mostramos que plantios mistos consumiram menos água do que monocultivos; que Eucalyptus reduziu a performance hidráulica de uma espécie nativa de rápido crescimento; e que o crescimento das árvores foi influenciado por mudanças na ecofisiologia do uso da água. Na última parte, nós mostramos que uma alta diversidade de espécies arbóreas fixadoras de nitrogênio facilitaram o crescimento de Eucalyptus; que Eucalyptus teve concentração de N ~30% mais alta na madeira, em plantios mistos; que o crescimento de árvores nativas não foi limitado pela competição por nutrientes com eucalipto; que eucalipto pode se beneficiar de maior disponibilidade de luz em plantios mistos; e que parcelas de espécies nativas interceptaram mais luz do que plantios mistos ou monocultivos de eucalipto. Essa pesquisa tem uma forte interface entre a ciência e a prática da restauração, e contribuiu para o desenvolvimento de novas maneiras de se restaurar as florestas tropicais por meio da aliança entre restauração e produção sob as perspectivas ecológica e econômica. Nossas descobertas indicam como avançar no futuro, a partir do estado da arte atual, em direção a sistemas de restauração florestal que minimizem a competição e maximizem o crescimento, como uma alternativa emergente e promissora para compensar os custos da restauração e superar a barreira econômica que ainda impede a restauração em larga escala. Essa pesquisa pode ser utilizada como uma base para se continuar adaptando a silvicultura a diferentes regiões e ecossistemas florestais. Olhando para o futuro mais distante, esses plantios mistos podem também representar um ponto inicial de um novo modelo de silvicultura que alia produção e conservação. A informação disponibilidade deve ser utilizada por cientistas, tomadores de decisão, planejadores e restauradores para avançar com a ciência e a prática da restauração e da silvicultura nos trópicos.
113

Processamento de imagens digitais e análise espacial para o estudo da susceptibilidade a incêndios florestais nas regiões do Apiaú e Ribeiro Campos - RR / Image processing techniques and space analyses for study to the susceptibily environment fires in Apiaú and Ribeiro Campos localities in Mucajaí - RR

Gladis de Fátima Nunes da Silva 30 November 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Analisa os fatores ambientais que contribuem para a ocorrência de incêndios florestais nas localidades de Apiaú e Ribeiro Campos em Mucajaí-RR com o emprego de técnicas de processamento de imagens digitais e análise espacial através da técnica Analytical Hierarchy Process (AHP) / This study has forest analyzes the environment factors which contribute to the occurrence of the environment fires in Apiaú and Ribeiro Campos localities in Mucajaí - RR with the employment of image processing techniques and space analyses through the Analytical Hierarchy Process (AHP)
114

SUBSÍDIOS PARA O PLANEJAMENTO DO MANEJO DE FLORESTAS TROPICAIS DA AMAZÔNIA / SUPPORT TO MANAGEMENT PLANNING IN AMAZONIA TROPICAL FORESTS

Braz, Evaldo Muñoz 05 March 2010 (has links)
The aim of this work is to rise up a procedure to support the management plans. This research is divided into seven chapters. In the first chapter, the introduction, with justification and the objectives of the work are referred. In the second chapter, a review of the literature about management of natural tropical forests is done, considering the difficulties, general and special conditions for effective implementation of the management of natural tropical forests. In the third chapter, it is defined the fundamental point of this work: to propose a procedure for calculating the cutting rate using the method BDq in combination with the growth of species with similar percentage volume increment. In the fourth chapter, it is suggested a procedure for detailed logging plan: road network planning; it was calculated the load and time of the skidder cycle; designed the size and performance of teams and all is compared with outputs obtained on the field. In the fifth chapter, using the method of ratio of diameter movement , fed with data from the permanent plot, a stand table projection of the diameter classes to assess the sustainability of cut rate for the period is done. The sixth chapter is a proposal for monitoring the management system. Finally, the seventh chapter analyses the economic viability of the compartment. Regarding the results for cutting rate from the compartment of 547 ha have been identified 3 groups of species with different rates of growth. Cut intensities were defined as 32.58% for group I; 48.62% for group II; and 56.23% % for group III. The total extraction for all compartment was 50.8%. The potential of the compartment was 17,021.46 m³ (31.11 m³ / ha), and the sustainable rate of cutting was 8,649.97 m³ (15.81 m³ / ha). To recover this extraction it is necessary a MAI of 0.63 m³ / ha / year. The logging indexes were: the optimal distance between landings was 540m. The optimum secondary road density calculated was 18.49 m / ha and the actual obtained in the field is, 21m/ha. The calculation of optimal number of landings was 24, to serve to 23 hectares each one, with capacity of 368m³ of timber in two stages, comprising only 0.22% of the area of the compartment. The maximum load capacity to Skidder was 7 ton in clay ground, dry, without structure and with a maximum gradient of 15%, and 4.6 ton in sand soil, slope of up to 10%. The average cycle time to skid was 11 minutes and 42 seconds; the average load of 6.11 tons was found. The stand table projection indicated an increase of mean annual increment (MAI) of 0.64 m³ / ha / year in the commercial classes (up to 45 DHB) and 0.67 m³ / ha / year in the above classes of 25 DBH. The ingress in the commercial classes was 4.17 trees per hectare to a cut cycle of 25 years. These data report that the recovery is feasible for the rate cut foreseen. It was also simulated a removal of all commercial classes (31.11 m³ / ha), and the result to cut cycle was an increment was 0.35 m³ / ha / year replacing only 28%. This reinforces the importance of evaluating the structure of the forest, besides the sustainable rate cut, to guarantee a replacement of adequate MAI. The girth limit for maximum production was 75 cm of DHB in this stand. The checklist about the sustainability of logging operations shows the adaptation of the enterprise to the new concepts of management. About the economical valuation, it was positive according Net Preset Value for the taxes of 6% a.a ., getting R$ 439,81/ha and R$ 240.579,31 for all compartment of 547 ha. / Esta pesquisa visa levantar procedimentos que devem ser incluídos nos planos de manejo. O trabalho está dividido em sete capítulos. No primeiro capítulo, são mencionados introdução, justificativa e objetivos do trabalho. No segundo capítulo, é realizada a revisão bibliográfica sobre o manejo das florestas naturais tropicais, avaliando as dificuldades, condições gerais e específicas para implantação efetiva do manejo das florestas naturais tropicais. No terceiro capítulo, foi definido o ponto fundamental do trabalho: propor um procedimento para cálculo da taxa de corte utilizando o método de Área Basal Máximo DAP-q em combinação com o crescimento de espécies com ritmo semelhante, baseado em seu incremento percentual em volume. No quarto capítulo, é detalhado o procedimento sugerido de planejamento da exploração, o planejamento de rede de estradas, o cálculo do ciclo de arraste e carga do skidder, além de projetado o dimensionamento das equipes e das performances e comparado com resultados obtidos na exploração. No quinto capítulo, utilizando-se o método de razão de movimentação, alimentado com dados de crescimento das espécies segundo as parcelas permanentes, é feita uma projeção das classes diamétricas visando avaliar a sustentabilidade da taxa de corte para o período considerado. No sexto capítulo, é apresentada uma proposta de monitoramento das empresas com alguns resultados de pesquisas já realizadas na área ou em compartimentos contíguos. E, finalmente, no sétimo capítulo, são realizadas análises de viabilidade econômica do compartimento em diferentes situações de venda da madeira. Com relação aos resultados para taxa de corte do compartimento de 547 ha, foram definidos 3 grupos de espécies com diferentes ritmos de crescimento. Assim, foram definidas intensidades de corte de 32,58% para o grupo I; 48,62% para o grupo II; e 56,23% para o grupo III. Em conjunto, a extração ficou em 50,8% sobre as classes comerciais. O potencial do compartimento era de 17.021,46 m³ (31,11m³/ha) e a taxa de corte sustentável orçou em 8.649,97 m³ (15,81 m³/ha). Para recuperar essa extração, será necessário um incremento médio anual de 0,63 m³/ha/ano. Os cálculos de planejamento da exploração indicaram para a distância ótima entre estaleiros o valor de 540 m. A densidade ótima de estradas calculada foi de 18,49m/ha e a real obtida em campo foi 21m/ha. O número ótimo de pátios calculado foi de 24 pátios de estocagem, visando servir a 23 hectares cada um, com capacidade de 368m³ de madeira por pátio em duas etapas, perfazendo apenas 0,22% da área do compartimento. As cargas máximas calculadas para o skidder na unidade de produção foram de 7 ton em terreno argiloso, seco, sem estruturação e com um máximo de 15% de inclinação, e de 4,6 ton em areia solta e inclinação máxima de 10%. O tempo de ciclo médio do trator de arraste foi de 11 minutos e 42 segundos; a carga média encontrada foi de 6,11ton. A prognose de incremento indicou um incremento médio anual (IMA) de 0,64m³/ha/ano nas classes comerciais (acima de 45 de DAP) e 0,67m³/ha/ano nas classes acima de 25 de DAP. O ingresso nas classes comerciais foi de 4,17 árvores por hectare para um ciclo de 25 anos. Esses dados informam que a recuperação é viável para a taxa de corte considerada. Foi também simulada uma remoção de todas as classes comerciais (31,11 m³/ha), e o resultado como incremento para 25 anos foi de 0,35/ha/ano, repondo apenas 28% do retirado. Isso reforça a importância da avaliação da estrutura da floresta, além da taxa de corte, para garantia de um IMA passível de reposição. A classe de DAP de máxima produção nesse povoamento é a de 75 cm. Foi elaborado um checklist para checagem da sustentabilidade do sistema de manejo utilizado, havendo boa aceitação da empresa às novas técnicas de exploração. A avaliação econômica foi positiva com relação ao valor presente líquido a uma taxa de 6% a.a., atingindo R$ 439,81/ha e R$ 240.579,31 para todo o compartimento de 547 ha.
115

Legacies of tropical forest fragmentation and regeneration for biodiversity and carbon storage

Jones, Isabel L. January 2017 (has links)
Expanding anthropogenic development within the tropical forest biome is driving the loss of an irreplaceable global resource. Mega-diverse tropical forests are vital for regulating the global carbon cycle, and are essential for climate change mitigation. Today, over half of the world’s remaining tropical forest is degraded or regenerating secondary forest. Tropical forests are becoming increasingly fragmented through the expansion of agriculture and roads. Landscape-scale flooding of terrestrial habitats caused by dam construction is an emerging driver of habitat loss and fragmentation. Much attention has been paid to the long-term impacts of tropical forest fragmentation for biodiversity, ecosystem functioning, and carbon emissions. Most of our understanding of the impacts associated with habitat fragmentation originates from systems in which the habitat matrix surrounding remnant forest patches is another, albeit low quality, terrestrial habitat. However, dam-induced habitat fragmentation results in remnant terrestrial biological communities becoming isolated on islands within a water matrix. A water matrix presents the worst-case scenario for remnant habitat fragments. In Chapter 2 I synthesise the results of numerous studies reporting the responses of taxonomic groups to isolation on reservoir land-bridge islands, and uncover a globally-applicable pattern of extinction debt acting upon remnant biological communities on reservoir islands. All islands, regardless of taxonomic group, habitat type, or island area lose species as island isolation time increases. Moreover, I show that contrary to existing ecological theory, once terrestrial habitat becomes isolated within a water matrix, it is effectively too isolated for species losses to be buffered by metapopulation dynamics. Dam development is rapidly expanding in the largest remaining tract of intact tropical forest, the Amazon Basin. In Chapters 3 and 4 I study the Balbina mega-dam system in the central Brazilian Amazon. Here, I use detailed field inventories of trees and lianas on islands and in continuous mainland habitat to determine the impact of landscape-scale habitat fragmentation caused by reservoir creation on these taxonomic groups. I find that islands maintain tree communities at significantly lower densities, richness and diversity compared to continuous forest. Furthermore, tree communities on islands exhibit compositional divergence from those found in mainland continuous forest. Island tree assemblages are dominated by low-wood density species, and may be on a trajectory towards communities characteristic of early successional forests with reduced carbon storage capacity. In contrast, liana assemblages remain compositionally intact and are becoming increasingly dominant relative to trees. Thus, lianas appear robust to many of the negative impacts associated with landscape-scale habitat fragmentation. As insular tree communities continue to degrade through area- and edge-effects, lianas may become a key feature of this archipelagic landscape due to their competitive advantage over trees in disturbed forest habitats. Lianas significantly inhibit tree recruitment and carbon storage. Thus, findings from Chapters 3 and 4 provide strong evidence for additional, and currently unaccounted-for biodiversity and carbon impacts associated with tropical dams. As development of tropical forest regions increases, there is an urgent need to reconcile the need for resources with the need for ecosystem service provision, such as carbon storage, particularly as we attempt to mitigate the impacts of rising atmospheric carbon. Recent studies have shown that secondary tropical forests have the potential to rapidly uptake atmospheric carbon, and act as a powerful tool in climate change mitigation policy. Broad-scale estimates of secondary forest carbon uptake are currently based on above-ground biomass alone. In Chapter 5 I present carbon stock estimates of additional tropical forest carbon pools - soil and dead woody biomass - in secondary forests ranging from 40-120 years. I find that soil fertility (nitrogen concentration) is key in determining carbon storage in secondary forests, and that the stability of carbon stocks held in dead woody biomass increases with secondary forest stand age. I highlight the need to integrate detailed site-specific information into broad-scale predictive models of secondary tropical forest carbon sequestration. This thesis links ecological theory and landscape-scale field inventories, to provide new understanding of the long-term costs of tropical forest fragmentation for biodiversity conservation and carbon storage, and provides further evidence of the important role secondary tropical forests may play in carbon sequestration and climate change mitigation.
116

Apport de l’analyse texturale des images radar à haute résolution spatiale pour la cartographie des forêts tropicales / Contribution of textural analysis from high spatial resolution radar images for tropical forest mapping

Benelcadi, Hajar 19 December 2014 (has links)
Depuis 2007, une nouvelle génération de capteurs RSO (RADAR à Synthèse d'Ouverture) a été mise en orbite. Ces capteurs (TerraSAR-X, Cosmo-SkyMed, RADARSAT-2, Sentinel) sont caractérisés par des résolutions spatiales métriques à la différence des capteurs précédents (ERS, JERS, ALOS, ASAR) de résolution spatiale d'une vingtaine de mètres. La résolution spatiale métrique met en évidence une information texturale intéressante qui était inaccessible avec les RSO satellitaires existants précédemment. Les travaux de cette thèse ont pour but d'évaluer le potentiel de l'analyse texturale des images RADAR à haute résolution spatiale, pour la classification des forêts tropicales. Trois différents sites d'étude avec différentes problématiques ont été choisis pour évaluer l'apport de l'analyse texturale au Cambodge, Cameroun et Brésil. La méthode d'analyse texturale des images est réalisé moyennant les paramètres de texture de Haralick, paramètres statistique de second ordre. Une classification supervisée, en utilisant la méthode SVM (Support Vector Machine) a été adopté pour évaluer l'apport des paramètres de texture utilisés / Since 2007, a new generation of SAR sensors (Synthetic Aperture RADAR) was launched. These sensors (TerraSAR-X, Cosmo-SkyMed, RADARSAT-2, and Sentinel) are characterized by metric spatial resolutions unlike previous sensors (ERS, JERS, ALOS, ASAR) with a spatial resolution of about twenty meters. Metric spatial resolution highlights interesting textural information that was inaccessible with the previously existing SAR sensors. This thesis aims at evaluating the contribution of textural analysis from high spatial resolution images for tropical forests mapping. Three different study sites with different problematic have been chosen to evaluate the textural analysis in Cambodia, Cameroun and Brazil. Indeed, the contribution of the analysis of textural information for classification has been emphasized. The latter is understood through the analysis of Haralick textural parameters, second order statistic parameters. The retained algorithm of classification is the SVM (Support Vector Machine), as it allows taking into account numerous parameters, which can be heterogeneous with respect to their physical dimension
117

Aspectos ecológicos e sócio-econômicos do manejo de Euterpe precatoria Mart. (Açaí) em áreas extrativistas no Acre, Brasil / Ecological and socioeconomic aspects of the management of Euterpe precatoria Mart. (Açaí) in extractive areas in Acre, Brazil

Elektra Rocha 10 April 2002 (has links)
Os seringueiros localizados dentro de reservas e assentamentos extrativistas no Estado do Acre, Amazônia Ocidental, Brasil, possuem como meio econômico o extrativismo da borracha e da castanha e pretendem diversificar a produção com outros recursos florestais que complementem a renda a curto prazo, respeitando ao mesmo tempo os seus modos tradicionais de vida e a diversidade biológica. O conceito do manejo dos frutos de Euterpe precatoria (Açaí) engloba aspectos sociais, econômicos e ecológicos concernentes a floresta. Este estudo fez uma análise do potencial ecológico e sócio econômico da extração de frutos do Açaí em áreas da Reserva Extrativista Chico Mendes e do Seringal Caquetá, Acre, para responder: (1) E. precatoria possui características populacionais como grande produção de frutos, alta densidade e regeneração natural, estrutura e estabilidade populacional que podem favorecer o seu manejo sustentável? (2) Qual é a estimativa da colheita sustentável para áreas de florestas no Caquetá? (3) Qual a forma de organização comunitária para a produção de Açaí? (4) Qual é a rentabilidade do manejo dos frutos no Seringal Caquetá? (5) Quais as práticas necessárias para o bom manejo do recurso? No levantamento do potencial ecológico foram avaliados a densidade, estrutura populacional, potencial produtivo, dinâmica e estabilidade populacional em florestas inundadas e de Terra Firme. Através de um modelo de matriz foi feita a simulação da quantidade de frutos que podem ser retirados da floresta sem alterar a densidade atual da população. No levantamento sócio-econômico foram avaliados a forma de organização comunitária e a rentabilidade obtida com o manejo do Açaí, da castanha e da borracha e com a diária local de trabalho. E. precatoria apresentou um alto potencial de manejo devido a sua alta densidade, estrutura populacional em forma de J invertido, alta freqüência, alta produção de frutos e estabilidade populacional de crescente a estável. A simulação da colheita de frutos na floresta de Baixio mostrou que a manutenção de 50% do recrutamento inicial é necessária para manter a estabilidade da população, isto é, a cada duas palmeiras, coleta-se frutos em apenas uma. Na Terra Firme é necessário a manutenção de 25% do recrutamento inicial, ou a cada quatro palmeiras coleta-se frutos em três. A organização comunitária em mutirão ou estrutura familiar deve se adequar de acordo com a disponibilidade de recursos para a atividade produtiva das diferentes famílias, tais como, mão de obra, animais de carga e mercados. A remuneração que a comunidade do Caquetá pode conseguir com a comercialização do Açaí foi maior que a conseguida com a borracha ou com diária local. Com a castanha a renda do Açaí foi similar, mas poderia ser maior, caso tivesse o mesmo subsídio para o transporte. / Rubber tappers in extractive reserves and settlements in Acre State, Western Amazonia, Brazil, live from rubber and brazil nuts extraction and recently started to be interested in diversification of their production with other forest resources that could complement their annual income in the short term, while at the same time preserving their traditional way of life and also biodiversity. The concept of fruit management of Euterpe precatoria (Açaí) encompasses social, economic and ecological aspects related to the forest. This study analyzes the social, economic and ecological potential of fruit extraction of Açaí in areas of the Extractive Reserve Chico Mendes and the Seringal Caquetá, Acre State to answer some questions: (1) Does E. precatoria have populational characteristics such as great production of fruits, high natural density and regeneration, population structure and stability that allow its sustainable management? (2) What is the estimate for sustainable harvest in forested areas in Caquetá? (3) What is the community organization for Açaí production? (4) What is the fruit management profitability in Seringal Caquetá?(5) What are the right practice for a good resource management? For the inventory of ecological potential, we evaluated density, population structure, production potential, population dynamics and stability in seasonal flooded and upland forests. A matrix model was applied to simulate the amount of fruits that could be harvested from the forest without altering the current population density. In the social and economic inventory we evaluated the way the community is organized to work and the profitability achieved with the Açaí, rubber and Brazil nut management, and each product profit per year. E. precatoria showed a very high management potential due to its high density, population structure in a inverted J shaped, high frequency, high fruit production and a increasing to stable population stability. The simulation of fruit harvest in the seasonal flooded forest showed that the maintenance of 50% of the initial recruitment is necessary for the stability of the population, therefore from each two palms only one should be harvested for a sound sustainable management. In upland forest the initial recruitment must be 25%, or from each four palms, three could be harvested. The community organization in a structural family must adapt to the productive system of each family, such as labor, animals for transportation and market availability. The profit that the Caquetás community can achieve with the commercialization of Açaí was greater than the achieved with rubber and other economic activities. The Açai profit is similar to Brazil nuts extraction, but could be higher if it had the same transportation subsidies that the nut receives.
118

The Soil Moisture Niche in a Moist Tropical Forest – A Demographic Approach

Kupers, Stefan Jonathan 16 January 2020 (has links)
Water availability affects tree species performance and distributions in tropical forests. However, there are no studies that have measured detailed spatial variation in soil water availability within a tropical forest. This limits our understanding of how water availability shapes the demography and distributions of tree species within tropical forests. In this dissertation, I measured detailed spatial variation in soil water potential (SWP), the relevant measure of water availability for plant performance, in the seasonal tropical moist forest of the 50-ha Forest Dynamics Plot on Barro Colorado Island, Panama. In Paper 1, I mapped spatial variation in SWP across the 50-ha plot in various stages of the dry season using information on topography, soil type, dry season intensity and more. In Paper 2, I quantified the soil moisture niches of species in terms of demographic responses (growth and mortality) and species distributions. I related seedling growth and mortality responses to SWP of 62 species to their distributional centre along the SWP gradient, using data from 20 years of annual seedling censuses across 200 seedling census sites. I found that species that grew faster (slow) with increasing SWP were more common on wetter (drier) parts of the SWP gradient. Moreover, wet-distributed species grew faster on the wet side of the SWP gradient than dry-distributed species. Mortality was unrelated to species distributions but decreased strongly with seedling height. These findings indicate that species with a growth advantage with respect to SWP grow faster out of the vulnerable small size ranges, reducing their mortality in later seedling stages and thus shaping species distributions indirectly. This mechanism is a form of niche differentiation that contributes to species coexistence. In Paper 3, I related seedling growth and mortality responses to spatiotemporal variation in water availability with responses to light availability, another highly limiting resource in tropical forests. I found an interspecific trade-off in responses to shade versus inter-annual drought (dry season intensity): species that performed relatively well in the shade performed worse during more severe dry seasons and vice versa. This trade-off enables coexistence, because species are adapted to perform well under either shade or drought. In sum, water availability contributes to the maintenance of the high diversity of tropical forests through hydrological niche differentiation and a trade-off between performance in shade versus drought. Future work can use my SWP maps and species responses to SWP to identify the functional traits that underlie the species responses and improve Dynamic Global Vegetation Models. Finally, my work facilitates the prediction of future species composition, diversity and ecosystem functioning of tropical forests with shifts in rainfall patterns caused by climate change.
119

Structure and restoration of natural secondary forests in the Central Highlands, Vietnam

Bui, Manh Hung 02 December 2016 (has links)
Introduction and objectives In Vietnam, the forest resources have been declining and degrading severely in recent years. The degradation has decreased the natural forest area, changed the forest structure seriously and reduced timber volume and biodiversity. From 1999 to 2005, the rich forest area has decreased 10.2%, whereas the poor secondary forest has increased dramatically by 20.7%. Forest structure plays an important role in forestry research. Understanding forest structure will unlock an understanding of the history, function and future of a forest ecosystem (Spies, 1998). The forest structure is an excellent basis for restoration measures. Therefore, this research is necessary to contribute to improving forest area and quality, reducing difficulties in forest management. The study also enhances the grasp of forest structure, structure changes after harvesting and fills serious gaps in knowledge. In addition, the research results will contribute to improving and rescuing the poor secondary forest and restoring it, approaching the old-growth forest in Vietnam. Material and methods The study was conducted in Kon Ka Kinh national park. The park is located in the Northeastern region of Gia Lai province, 50 km from Pleiku city center to the Northeast. The park is distributed over seven different communes in three districts: K’Bang, Mang Yang and Đăk Đoa. Data were collected from 10 plots of secondary forests (Type IIb) and 10 plots of primeval forests (Type IV). Stratified random sampling was applied to select plot locations. 1 ha plots were used to investigate gaps. 2000 m2 plots were used to measure overstorey trees such as diameter at breast height, total height, crown width and species names. 500 m2 subplots were used to record tree positions. For regeneration, 25 systematic 4 m2 subplots were established inside 1 ha plots. After data were collected in the field, data analyses were conducted by using R and Excel. Firstly, some stand information, such as density, volume and so on, was calculated, and then descriptive statistics were computed for diameter and height variables. Linear mixed effect models were applied to analyze the difference of diameter and height and to check the effect of random factor between the two forest types. Diameter and height frequency distributions were also generated and compared by using permutational analysis of variance (PERMANOVA). Non-linear regression models were analyzed for diameter and height variables. Similar analyses were implemented for gaps. Regarding spatial point patterns of overstorey trees, replicated point pattern analysis techniques were applied in this research. For biodiversity, some calculations were run such as richness and biodiversity indices, comparison of biodiversity indices by using linear mixed models and biodiversity differences between two forest types tested again by permutational analysis of variance. In terms of regeneration, some analyses were implemented such as: height frequency distribution generation, frequency difference testing, biodiversity indices for the regeneration and spatial distribution checking by using a nonrandomness index. Results and discussion After analyzing the data, some essential findings were obtained as follows: Hypothesis H1 “The overstorey structure of secondary forests is more homogeneous and uniform than old-growth forests” is accepted. In other words, the secondary forest density is about 1.8 times higher than the jungle. However, the volume is only 0.56 times as large. The average diameter and height of the secondary forest is smaller by 5.71 cm and 3.73 m than the old-growth forest, respectively. Linear mixed effect model results indicate that this difference is statistically different and the effect of the random factor (Section) is not important. Type IIb has many small trees and the diameter frequency distribution is quite homogeneous. The old-growth forest has more big trees. For both forest stages, the height frequency distribution is positively skewed. PERMANOVA results illustrate that the frequency distribution is statistically different between the two forest types. Regression functions are also more variant and diverse in the old-growth forest, because all standard deviations of the parameters are greater there. Gap analysis results indicate that the number of gaps in the young forest is slightly higher, while the average gap size is much smaller. The gap frequency distribution is statistically different between the two types. In terms of the spatial point pattern of overlayer trees, the G-test and the pair correlation function results show that trees distribute randomly in the secondary forest. In contrast, the spatial point patterns of trees are more regular and diverse in the old-growth forest. The spatial point pattern difference is not significant, and this is proved by a permutational t-test for pair correlation function (pcf). Envelope function results indicate that the variation of pcf in young forests is much lower than in the primary forests. Hypothesis H2 “The overstorey species biodiversity of the secondary forest is less than in the old-growth forest” is rejected. Results show that the number of species of the secondary forest is much greater than in the old-growth forest, especially richness. The richness of the secondary forest is 1.16 times higher. The Simpson and Shannon indices are slightly smaller in the secondary forest. The average Simpson index for both forest stages is 0.898 and 0.920, respectively. However, the difference is not significant. Species accumulation curves become relatively flatter on the right, meaning a reasonable number of plots have been observed. Estimated number of species from accumulation curves in two forest types are 105 and 95/ha. PERMANOVA results show that number of species and proportion of individuals in each species are significantly different between forest types. Hypothesis H3 “The number regenerating species of the secondary forest is less and they distribute more regularly, compared to the old-growth forest” is rejected. There are both similarities and differences between the two types. The regeneration density of the stage IIb is 22,930 seedlings/ha, greater than the old forest by 9,030 seedlings. The height frequency distribution shows a decreasing trend. Similar to overstorey, the richness of the secondary forest is 141 species, higher than the old-growth forest by 9 species. Biodiversity indices are not statistically different between two types. PERMANOVA results indicate that the number of species and the proportion of individuals for each species are also not significantly different from observed forest types. Nonrandomness index results show that the regeneration distributes regularly. Up to 95% of the plots reflect this distribution trend. Hypothesis H4 “Restoration measures (with and without human intervention) could be implemented in the regenerating forest” is accepted. The investigated results show that the secondary forest still has mother trees, and it has enough seedlings to restore. Therefore, restoration solutions with and without human intervention can be implemented. Firstly, forest protection should be applied. This measure is relevant to national park regulations in Vietnam. Rangers and other related organizations will be responsible for carrying out protection activities. These activities will protect forest resources from illegal logging, grazing and tourist activities. Environmental education and awareness-raising activities for indigenous people is also important. Another measure is additional and enrichment planting. It should focus on exclusive species of the overstorey in Type IIb or exclusive species of the primary forest. Selection of these species will lead to species biodiversity increase in the future. This also meets the purpose of the maximum biodiversity solution. Conclusion Forest resources play a very important role in human life as well as maintaining the sustainability of ecosystems. However, at present, they are under serious threat, particularly in Vietnam. Central Highland, Vietnam, where forest resources are still relatively good, is also threatened by illegal logging, lack of knowledge of people and so on. Therefore, it needs the hands of the people, especially foresters and researchers. Through research, scientists can provide the knowledge and understanding of the forest, including the structure and forest restoration. This study has obtained important findings. The secondary forest is more homogeneous and uniform, while the old-growth forest is very diverse. Biodiversity of the overstorey in the secondary forest is more than the primary. The number of regenerating species in the secondary forest is higher, but other indices are not statistically different between two types. The regeneration distribute regularly on the ground. The secondary forest still has mother trees and sufficient regeneration, so some restoration measures can be applied here. Findings of the study contribute to improve people’s understanding of the structure and the structural changes after harvesting in Kon Ka Kinh national park, Gia Lai. That is a key to have better understandings of the history and values of the forests. These findings and the proposed restoration measures address rescuing degraded forests in Central Highland in particular and Vietnam in general. And further, this is a promising basis for the management and sustainable use of forest resources in the future.:TABLE OF CONTENTS ACKNOWLEDGEMENTS I TABLE OF CONTENTS III LIST OF FIGURES VIII LIST OF TABLES XI LIST OF ABBREVIATIONS XII SUMMARY XIII CHAPTER I: INTRODUCTION 1 1.1. The decline of natural forest resources, orientation of difficulty and development in Vietnam 1 1.1.1. Decline of forest resources 1 1.1.2. Difficulties in forestry management 1 1.1.3. Management strategies 2 1.2. Forest structure role 3 1.3. Forest restoration in Vietnam 4 1.4. Importance of old-growth and secondary forests 4 1.5. Aims, scope and hypotheses 6 1.5.1. Aims 6 1.5.1.1. General objective 6 1.5.1.2. Specific objective 6 1.5.2. Scope 6 1.5.3. Hypotheses 6 CHAPTER II: LITERATURE REVIEW 8 2.1. Tropical forest structure analysis 8 2.1.1. History 8 2.1.1.1. Overstorey 8 2.1.1.2. Regeneration 12 2.1.2. Structural attributes of tropical forests 13 2.1.2.1. Overstorey 14 a. Analyzed attributes 14 b. Relevant attributes to this study 15 2.1.2.2. Regeneration 21 2.2. Secondary tropical forest restoration 22 2.2.1. Strategies for secondary forest restoration 23 2.2.1.1. Protection and natural recovery 24 2.2.1.2. Natural regeneration management 24 a. Growing conditions and yield of desirable regeneration improvement 24 b. Desirable regeneration assistance 25 2.2.1.3. Accelerated Natural Regeneration (ANR) 25 2.2.1.4. Enrichment planting 25 2.2.1.5. The framework species method 26 2.2.1.6. Maximum diversity planting method 26 CHAPTER III: MATERIAL 27 3.1. Natural conditions of the study area 27 3.1.1 Geographic location, boundaries and area of Kon Ka Kinh national park 27 3.1.2. Topography, geology and soil 28 3.1.2.1. Topography 28 3.1.2.2. Geology and soil 29 3.1.3. Climate and hydrology 30 3.1.3.1. Climate 30 3.1.3.2. Hydrology 31 3.2. Vegetation in Kon Ka Kinh national park 31 3.2.1. The area of land use types 31 3.2.2. Plant biodiversity 33 3.2.3. The flora and forest vegetation 33 3.2.3.1. Flora 33 3.2.3.2. Forest vegetation 34 3.2.3.3. History of forest exploitation in the park 35 3.3. Assessing the natural conditions and vegetation of the park 37 3.4. Population, ethnicity and labor 38 3.4.1. Population 38 3.4.2. Labor and ethnicity 39 3.4.3. Poverty status 40 3.5. Forest resources classification 40 3.5.1. The Loeschau’s classification system 40 3.5.2. The relationship between forest types with development phases 42 CHAPTER IV: METHODOLOGY 45 4.1. Plot establishment method 45 4.2. Data collection method 47 4.2.1. Data collection for overstorey stem maps 47 4.2.1.1. Tree data collection 47 4.2.1.2. Tree positions 50 4.2.1.3. Gap inventory 51 4.2.2. Data collection for regeneration 52 4.3. Data analysis method 55 4.3.1. Applied methods for the upper layer 55 4.3.1.1. Stand information 55 a. Calculation for each tree 55 b. Calculation for a stand 55 4.3.1.2. Descriptive statistics for height and diameter variables 56 a. Central tendency 56 b. Dispersion and variability 56 c. Measures of distribution shape 57 4.3.1.3. Linear mixed-effects analysis 59 a. Applications with this study and data arrangement 60 b. Homoscedasticity checking 61 c. Checking autocorrelation 63 d. Checking normal distribution of the residuals 66 e. Model selection and information summary 67 4.3.1.4. Frequency distribution 68 a. Generating frequency distributions 68 b. Frequency distribution difference testing 69 4.3.1.5. Diameter-height regression analysis 70 a. Used function forms 70 b. Theoretical calculations 71 c. Model selection 73 4.3.1.6. Gap analysis 74 a. Descriptive statistics for gaps 74 b. Calculating the gap area proportion for each forest type 74 c. Gap size frequency distribution 74 d. Gap size frequency distribution difference testing 75 4.3.1.7. Spatial point patterns of tree species 75 a. Applications 76 b. Tree density analysis 77 c. Testing for randomness 78 d. Comparing point pattern variation 83 e. Testing the difference between forest types 84 4.3.1.8. Overstorey tree species diversity analysis 85 a. Richness and species importance value index (SIVI) 85 b. Species diversity index 86 c. Species accumulation curve 88 d. Biodiversity index comparison 88 e. Tree species diversity comparison 89 4.3.2. Regenerating tree storey structure analysis 90 4.3.2.1. Frequency distribution of regeneration 90 4.3.2.2. Height frequency distribution difference testing 91 4.3.2.3. Biodiversity indices for regeneration 91 4.3.2.4. Biodiversity index comparison by using LMM 91 4.3.2.5. Regeneration species diversity comparison 91 4.3.2.6. Regeneration spatial distribution checking 91 a. Nonrandomness index 91 b. Nonrandomness index value comparison 92 CHAPTER V: RESULTS 93 5.1. Overstorey structure analysis results 93 5.1.1. Stand information 93 5.1.2. Descriptive statistics results 95 5.1.3. Linear mixed effect model results 97 5.1.3.1. Box plots for the diameter and height variables 97 5.1.3.2. Model analysis and adaptation 97 5.1.3.3. Model parameter estimation 100 5.1.4. Frequency distributions 101 5.1.4.1. Frequency distribution results for both types 101 5.1.4.2. Frequency distribution difference 107 5.1.5. Diameter-height regression results 107 5.1.5.1. Estimated parameters 107 5.1.5.2. Model selection 110 5.1.5.3. Regression charts 110 5.1.6. Gap analysis 116 5.1.6.1. Gap descriptive information 116 5.1.6.2. Gap area ratio 117 5.1.6.3. Gap size frequency distribution 117 5.1.6.4. Gap size frequency distribution difference testing results 120 5.1.7. Spatial distribution analysis 120 5.1.7.1. Density testing results 120 5.1.7.2. Randomness checking results 122 5.1.7.3. Variation difference between two types 123 5.1.7.4. Point pattern difference testing between two types 124 5.1.8. Overstorey species diversity analysis results 125 5.1.8.1. Richness, SIVI and biodiversity indices 125 5.1.8.2. Biodiversity index comparison by using LMM 127 5.1.8.3. Tree species diversity comparison 127 5.2. Regeneration storey structure analysis results 128 5.2.1. Height frequency distribution 128 5.2.2. Height frequency distribution difference testing 130 5.2.3. Biodiversity index for regeneration 131 5.2.4. Biodiversity index difference comparison 133 5.2.5. Regeneration species diversity comparison 133 5.2.6. Regeneration spatial distribution 134 5.2.6.1. Nonrandomness index results 134 5.2.6.2. Nonrandomness index value testing results 134 CHAPTER VI: DISCUSSION 135 6.1. Overstorey structure differentiation 135 6.1.1. Structure and spatial distribution difference 135 6.1.1.1. Stand information 135 6.1.1.2. Statistical descriptions for diameter and height 136 6.1.1.3. Diameter and height growth difference testing by linear mixed effect models 137 6.1.1.4. Frequency distribution dissimilarity 138 6.1.1.5. Diameter-height regression 139 6.1.1.6. Canopy gaps 140 6.1.1.7. Spatial distribution patterns 141 6.1.2. Biodiversity distinction of overstorey trees 143 6.2. Regeneration dissimilarity 145 6.2.1. Density and frequency distribution 145 6.2.2. Biodiversity indices 146 6.2.3. Spatial distribution of regeneration 147 6.3. Proposing restoration measures 147 6.4. Improved points in this research 150 CHAPTER VII: CONCLUSION AND RECOMMENDATION 152 7.1. Conclusion 152 7.2. Suggestions for further research 154 REFERENCES 156 APPENDIX 180
120

Complex land cover classifications and physical properties retrieval of tropical forests using multi-source remote sensing

Wijaya, Arief 30 April 2010 (has links)
The work presented in this thesis mainly focuses on two subjects related to the application of remote sensing data: (1) for land cover classification combining optical sensor, texture features generated from spectral information and synthetic aperture radar (SAR) features, and (2) to develop a non-destructive approach for above ground biomass (AGB) and forest attributes estimation employing multi-source remote sensing data (i.e. optical data, SAR backscatter) combined with in-situ data. Information provided by reliable land cover map is useful for management of forest resources to support sustainable forest management, whereas the generation of the non-destructive approach to model forest biophysical properties (e.g. AGB and stem volume) is required to assess the forest resources more efficiently and cost-effective, and coupled with remote sensing data the model can be applied over large forest areas. This work considers study sites over tropical rain forest landscape in Indonesia characterized by different successional stages and complex vegetation structure including tropical peatland forests. The thesis begins with a brief introduction and the state of the art explaining recent trends on monitoring and modeling of forest resources using remote sensing data and approach. The research works on the integration of spectral information and texture features for forest cover mapping is presented subsequently, followed by development of a non-destructive approach for AGB and forest parameters predictions and modeling. Ultimately, this work evaluates the potential of mosaic SAR data for AGB modeling and the fusion of optical and SAR data for peatlands discrimination. The results show that the inclusion of geostatistics texture features improved the classification accuracy of optical Landsat ETM data. Moreover, the fusion of SAR and optical data enhanced the peatlands discrimination over tropical peat swamp forest. For forest stand parameters modeling, neural networks method resulted in lower error estimate than standard multi-linear regression technique, and the combination of non-destructive measurement (i.e. stem number) and remote sensing data improved the model accuracy. The up scaling of stem volume and biomass estimates using Kriging method and bi-temporal ETM image also provide favorable estimate results upon comparison with the land cover map. / Die in dieser Dissertation präsentierten Ergebnisse konzentrieren sich hauptsächlich auf zwei Themen mit Bezug zur angewandten Fernerkundung: 1) Der Klassifizierung von Oberflächenbedeckung basierend auf der Verknüpfung von optischen Sensoren, Textureigenschaften erzeugt durch Spektraldaten und Synthetic-Aperture-Radar (SAR) features und 2) die Entwicklung eines nichtdestruktiven Verfahrens zur Bestimmung oberirdischer Biomasse (AGB) und weiterer Waldeigenschaften mittels multi-source Fernerkundungsdaten (optische Daten, SAR Rückstreuung) sowie in-situ Daten. Eine zuverlässige Karte der Landbedeckung dient der Unterstützung von nachhaltigem Waldmanagement, während eine nichtdestruktive Herangehensweise zur Modellierung von biophysikalischen Waldeigenschaften (z.B. AGB und Stammvolumen) für eine effiziente und kostengünstige Beurteilung der Waldressourcen notwendig ist. Durch die Kopplung mit Fernerkundungsdaten kann das Modell auf große Waldflächen übertragen werden. Die vorliegende Arbeit berücksichtigt Untersuchungsgebiete im tropischen Regenwald Indonesiens, welche durch verschiedene Regenerations- und Sukzessionsstadien sowie komplexe Vegetationsstrukturen, inklusive tropischer Torfwälder, gekennzeichnet sind. Am Anfang der Arbeit werden in einer kurzen Einleitung der Stand der Forschung und die neuesten Forschungstrends in der Überwachung und Modellierung von Waldressourcen mithilfe von Fernerkundungsdaten dargestellt. Anschließend werden die Forschungsergebnisse der Kombination von Spektraleigenschaften und Textureigenschaften zur Waldbedeckungskartierung erläutert. Desweiteren folgen Ergebnisse zur Entwicklung eines nichtdestruktiven Ansatzes zur Vorhersage und Modellierung von AGB und Waldeigenschaften, zur Auswertung von Mosaik- SAR Daten für die Modellierung von AGB, sowie zur Fusion optischer mit SAR Daten für die Identifizierung von Torfwäldern. Die Ergebnisse zeigen, dass die Einbeziehung von geostatistischen Textureigenschaften die Genauigkeit der Klassifikation von optischen Landsat ETM Daten gesteigert hat. Desweiteren führte die Fusion von SAR und optischen Daten zu einer Verbesserung der Unterscheidung zwischen Torfwäldern und tropischen Sumpfwäldern. Bei der Modellierung der Waldparameter führte die Neural-Network-Methode zu niedrigeren Fehlerschätzungen als die multiple Regressions. Die Kombination von nichtdestruktiven Messungen (z.B. Stammzahl) und Fernerkundungsdaten führte zu einer Steigerung der Modellgenauigkeit. Die Hochskalierung des Stammvolumens und Schätzungen der Biomasse mithilfe von Kriging und bi-temporalen ETM Daten lieferten positive Schätzergebnisse im Vergleich zur Landbedeckungskarte.

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