A alteração dos ecossistemas naturais e a criação de novos ambientes podem alterar significativamente o padrão de distribuição das espécies silvestres e a disponibilidade dos recursos naturais. A expansão agrícola pode ser considerada como uma das principais perturbações antrópicas responsáveis pela conversão das florestas nativas. Mamíferos de médio e grande porte são responsáveis por processos ecológicos determinantes na estrutura das comunidades. Estes possuem importantes funções na manutenção e regeneração das florestas e sua contínua provisão de bens e serviços ecossistêmicos. Dieta e uso do espaço estão intimamente relacionados ao potencial adaptativo das espécies. Seu estudo é útil na tentativa de avaliar a conservação das mesmas nos ambientes alterados. Neste contexto dois estudos envolvendo mamíferos de médio e grande porte foram conduzidos em paisagens agrícolas da Região do Alto Paranapanema, Estado de São Paulo. No primeiro estudo, entre setembro de 2008 e setembro de 2010, foi avaliada a freqüência de ocorrência das espécies deste grupo, em corpos dágua naturais e artificiais da Fazenda Três Lagoas, no município de Angatuba. Ambos os ambientes (açudes e riachos) estavam associados à plantação recente de Eucalipto. Foram detectadas 20 espécies no total (18 em açudes e 17 em riachos), sugerindo razoável riqueza de espécies para o ambiente em questão, no entanto os ambientes ripários (i.e., que abrigam os corpos dágua naturais) apontaram maior riqueza e abundância. Tais resultados reforçam a importância da presença de remanescentes florestais sob proteção legal na paisagem agrícola, para a conservação dos mamíferos de médio e grande porte. Além disto, os resultados sugerem aumento da capacidade de suporte do ambiente em função da manutenção dos açudes. O segundo estudo trata do uso de abrigos e dieta de Lontra longicaudis (Mammalia, Carnivora), mamífero carnívoro semi-aquático já considerado como espécie vulnerável. Entre agosto de 2008 e julho 2009, foi realizada a coleta mensal das fezes de lontra encontradas em trecho sob influência antrópica do rio Paranapanema. Os abrigos foram descritos e representados graficamente e a dieta foi quantificada por meio da análise de 60 amostras de fezes. Foram identificados 15 itens alimentares, sendo peixes das famílias Cichlidae e Loricariidae os itens mais comuns. A amplitude de nicho apontou a espécie como especialista (utilizando o índice padronizado de Levins), reforçando a importância do ambiente e fauna aquáticos para sua conservação. No entanto, os resultados sugerem, de forma geral, certa plasticidade de L. longicaudis em relação aos ambientes alterados. Ambos os estudos, sugerem a relevância de paisagens alteradas na conservação da biodiversidade, e a necessidade de inserção de tais áreas em planos de manejo e conservação. / The expansion of agricultural land is recognized as one of the most significant anthropic alterations within the natural ecosystems. The conversion of forest into agricultural landscapes can change biotic interactions and natural resources availability. Alterations as such can have consequences in respect to the ecosystems services which are provided by natural forested areas. Mammals are responsible for ecological processes which are determinant for the forest maintenance and regeneration. Diet and habitat use are essential tools to determine species conservation status and how it deals with human-driven ecological changes. Hence within this context, two studies took place in disturbed areas in Southern São Paulo State, Brazil. Both studies involve middle-to large sized mammals in agricultural landscapes at the Alto Paranapanema watershed. In the first study, during the period of August 2008 to July 2010, every two months, the frequency of occurrence of middle-to large sized mammals was surveyed and recorded around streams of remaining gallery forests and artificial reservoirs originally built for cattle water supply. Both habitats are associated with new Eucalyptus plantations. As a result a total of 20 species were detected, 18 around artificial reservoirs and 17 in streams of gallery forests. However streams of gallery forests showed significantly higher species richness and abundance than artificial reservoirs. These results outline the importance of maintaining protected native vegetation areas by law in such landscapes. Results also suggest that the artificial reservoirs may increase habitat carrying capacity for middle- to large-sized mammals in such circumstances. The second study reports the diet and use of shelters by the neotropical otter (Lontra longicaudis) in a disturbed area. Otters are semi-aquatic carnivores with a potentially functional role in freshwater ecosystems. During the period from August 2008 to July 2009, otter scats were collected monthly at Paranapanema River. The shelters were described and graphically represented and the diet was quantified by analyzing 60 scats. The niche breadth analysis classifies L. longicaudis as a specialist species according to the trophic niche amplitude index (Levins index). The most common items identified were fishes from the Cichlidae and Loricariidae families, probably because of the habits of such species which makes them an easier prey. Such results stress the importance of freshwater ecosystems for the neotropical otter conservation. Results also suggest the adaptative potential of L. longicaudis and that some disturbed areas may be significant for this species conservation. Both studies emphasize the relevance of such altered ecosystems and it insertion requirement on protection and conservation initiatives towards biodiversity conservation.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The research evaluates the floristic, phytogeographic contingent, ecological structure descriptors, spatial phytosociology and composition of ecological guilds of trees in a testimony mountain, also examines the variables of altimetry and morphometry. It was obtained the abiotic and biotic data in 15 sample units (10 x 50m), arranged in continuous transects the top of the mountain to base, totaling 7.500m2 of sampling. Trees data were recorded with the circumference at breast height ≥ 15,7cm (1,30m above at ground level). Environmental variables were derived from altimetry (altitude, slope and level difference) and morphometry (rocky outcrop, vertical curvature, sun exposure and soil depth), besides vegetation density and gaps (canopy openness). This master s dissertation has three chapters. The first chapter characterizes the floristic and phytogeographical contingent of trees. The second chapter evaluates the biological diversity: species richness, diversity (alpha biological diversity indices) and dominance models (ranking of abundance); and examines the exploratory analysis of the relationships between species and environmental variables. The third chapter analyzes the spatial phytosociology and the composition of ecological guilds in different ecological zones in the mountain slope. / A pesquisa avalia a florística, contingente fitogeográfico, descritores de estrutura ecológica, fitossociologia espacial e composição de guildas ecológicas da vegetação arbórea em um morro testemunho, também examina as variáveis de altimetria e morfometria. Obtiveram-se os dados abióticos e bióticos em 15 unidades amostrais (10 x 50m), dispostas em transectos contínuos, do topo a base do morro, perfazendo 7.500 m2 de amostragem. Registraram-se dados de árvores com a circunferência à altura do peito ≥ 15,7cm, (1,30m de altura ao nível do solo). As variáveis ambientais foram oriundas da altimetria (altitude, declividade e diferença de nível) e morfometria (afloramento rochoso, curvatura vertical, exposição solar e profundidade do solo), além da densidade de cobertura vegetal e clareiras (abertura do dossel). A presente dissertação possui três capítulos. O primeiro capítulo caracteriza a florística e o contingente fitogeográfico da vegetação arbórea. O segundo capítulo avalia a diversidade biológica: riqueza de espécies, heterogeneidade (índices de diversidade biológica alfa) e modelos de dominância (ranking de abundância); e examina a análise exploratória das relações entre as espécies e as variáveis ambientais. O terceiro capítulo analisa a fitossociologia espacial e composição de guildas ecológicas em diferentes zonas ecológicas na vertente do morro.

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<p dir="ltr">Forest ecosystems play a pivotal role in climate change mitigation. Sustainable forest management practices necessitate accurate quantification of forest aboveground carbon stocks (FACS). In the first part of this study, I compared the 13-year changes in FACS across three silvicultural systems, including even-aged management (EA), uneven-aged management (UEA), and non-harvested controls (NH), in Indiana's hardwood forests. Forest stands within each silvicultural system were assigned with one of the six treatment types, including clearcutting, shelterwood, or prescribed burning for EA, single-tree selection or patch cutting for UEA, or untreated controls. From 2008 to 2021, the FACS of the study area exhibited an increase from 91.5 ± 9.0 Mg/ha to 115.3 ± 2.1 Mg/ha. Single-tree selection, shelterwood, and prescribed burning were found to have minimal impacts on FACS. However, clearcutting and patch cutting resulted in a significant reduction in FACS, with subsequent recovery reaching only 30-37% of their pre-treatment levels after 13 years. Further investigations may use long-term inventory data to analyze the chronic recovery patterns on these sites.</p><p dir="ltr">In the second part of this study, I evaluated the feasibility of using 3DEP LiDAR in conjunction with the random forest algorithm for multiscale FACS prediction. It was found that the stand-scale model outperformed the plot-scale model, primarily due to a stand’s higher positioning accuracy and reduced boundary effects than the plot-scale model. This led to a reduction in RMSE from 25.43 Mg/ha (26%) to 16.74 Mg/ha (20%). Moreover, the stand-scale model exhibited robust landscape-level prediction performance even in scenarios where point density decreased from 7.7 points/m² to 2.0 points/m². However, the partitioned model including solely clearcut and patch sites produced a higher RMSE of 59% (17.82 Mg/ha) due to inaccurate LiDAR return classification and biased canopy height metrics extraction. Future research should delve into the mechanisms of point cloud classification to improve the FACS prediction accuracy for clearcut forest monitoring.</p><p dir="ltr">Overall, this thesis contributed to a deeper understanding of carbon dynamics in managed hardwood forests, highlighted the potential of using LiDAR technology for improved landscape-level carbon monitoring, and informed the decision-making processes in the context of climate change mitigation.</p><p><br></p>

Prescribed fire use in Virginia and West Virginia has increased over the past ten years as forest managers on public lands have increasingly used prescribed fire to meet management goals. These goals include hazardous fuel reduction, wildlife habitat restoration and management, and control of less desired vegetation. Research is needed to better understand the effects of wildland fire on forest ecosystems. In this study, we addressed wildland fire's effects on water, vegetation, and soil resources in the central Appalachian Region. Moreover, the long-term efficacy of various types of timber harvests on forest fuel reduction was analyzed. Over fifty peer-reviewed articles were evaluated to characterize the effects of prescribed fire on physical, chemical, and biological water quality parameters throughout the eastern United States. It was determined that fires of low to moderate intensity and severity may cause short-term sediment and nutrient increases in nearby waterbodies, but these effects often dissipate within 2-3 years. Effects on biological organisms are more transient, frequently lasting from a few weeks to a few months. Regeneration following wildfires at three sites in Virginia and West Virginia varied due to fire behavior and time since fire. Preferred and undesired species responded differently at each site. Follow-up treatments and continued monitoring are needed to obtain desired vegetative compositions post-fire. Two dormant season prescribed fires on the Fishburn Forest near Blacksburg, Virginia were studied for mineral soil chemistry effects. Both treatment and time affected macronutrient levels, but no differences were present 6 and 14 months post-fire between burned and unburned locations. Forest fuels were quantified approximately 20 years following different silvicultural harvests on the George Washington-Jefferson National Forest. Fuels of different size classes responded differently to different harvests as fine fuels were reduced by the high-leave shelterwood treatment, and coarse woody fuels were reduced by the clearcut and low-leave shelterwood treatments. Overall, low intensity and low severity fires induce minimal, potentially negative changes in water and soil quality. In contrast, wildfires of high intensity and severity may potentially contribute to changes in species composition and forest floor properties. Furthermore, varying levels of overstory removal may reduce extreme wildfire risk for decades. The findings of this study reinforce the need for continued research and monitoring of both wildfire effects and prescribed fire use in the central Appalachian Region. / Doctor of Philosophy / It is well-documented that fire has occurred in forested ecosystems for millennia. In addition to natural ignitions, indigenous peoples used fire for various reasons, such as understory reduction, hunting, and crop cultivation. As European settlers arrived and advanced across North America, they continued to use fire as a tool to shape the landscape to fit their societal needs. The use of fire by humans in North America all but ceased in the early 20th century. Large fire events in the western United States motivated the newly created United States Forest Service to restrict fire from the landscape. The fire exclusion policy of the early 20th century had unintended consequences, such as increased fire risk due to fuel accumulation and a shift from fire-tolerant species, such as oaks and pines, to fire-intolerant species. More recently, the perception of wildland fire has been re-examined due to ecological and societal issues. Although federal and state agencies are burning more acres, the public's wariness towards wildland fire is prevalent. As attitudes about wildland fire have changed, so have the research needs. Information regarding the effects of both wild and prescribed fires on forest ecosystems is needed throughout the United States, including the eastern United States, and more specifically, within the central and southern Appalachian Mountains. This dissertation discusses the effects of both wild and prescribed fires on various forests processes within these regions. In this dissertation, 1) the impacts of prescribed fire on water quality, 2) the responses of forest vegetation to wildfire, and 3) and the effects of prescribed fire on soil nutrients were investigated. Additionally, different timber harvests were studied to determine their long-term effects on potentially hazardous fuel loads. The results indicated that water quality is generally not impacted by low intensity and severity prescribed fires in the eastern United States. It was determined that vegetation often responds vigorously to wildfires, and subsequent species composition varies based on factors such as fire severity, site conditions, time since fire, and overstory species composition. When examining soil nutrients for 14 months following prescribed fires, nutrient changes occurred in both unburned and burned locations. When fuel loads were compared between timber harvests of varying intensities, woody fuels were reduced in the long-term. This reduction may minimize potential wildfire behavior and effects. While both wild and prescribed fires impact forest processes, they generally do so in different ways. This is mainly due to differences in fire behavior between these fire types. Effects of wildfires on water quality, soil chemistry, and vegetation tend to last longer than prescribed fire. Additionally, prescribed fire, when used in conjunction with other forest management activities, may reduce potentially negative wildfire impacts. Monitoring post-fire effects is critical to understanding the best way to use prescribed fire as a forest management tool.

The regeneration in oak-dominated stands following five silvicultural treatments was examined on four sites in the mountains of Virginia and West Virginia. Treatments included: silvicultural clearcut, leave-tree, commercial clearcut, shelterwood, and group selection. The effects of harvesting were compared among sites and among treatments. Oak regeneration dominance, measured by the relative density of dominant and codominant oak regeneration, was the most important variable calculated from the data. Oak regeneration dominance varied by site, but did not vary by silvicultural treatment; all treatments resulted in relatively low numbers. Therefore, the silvicultural treatments used here were not enough to overcome the site specific limitations to successful oak regeneration. Oak species also seemed to be less important in the regenerating stands than in their parent stands. The biggest losses in oak importance occurred on the intermediate and high quality sites; competitive oak regeneration was relatively scarce on two of the three sites with an oak site index (base age 50) of over 70 ft. Multiple linear regression analysis was used to identify the factors controlling oak regeneration at a smaller scale. The most important variables were those that described the oak stump sprouting potential, the understory and overstory oak component in the pre-harvest stand, post-harvest light and soil nitrogen levels. / Master of Science

A dieta de carnívoros e o uso do espaço por mamíferos de médio e grande porte foram estudados no Parque Ibiti (17.434 ha), uma área que engloba fazendas de plantações de eucaliptos nos municípios de Itararé e Itapeva, São Paulo. Foram selecionados três ambientes: Cerrado, Floresta Ombrófila Mista e Floresta Ombrófila Mista de crescimento secundário (Capoeira), para a coleta de dados durante o período de setembro de 2004 a fevereiro de 2006. O método utilizado para o estudo do uso do espaço foi a identificação de espécies através de vestígios em transeções pré-estabelecidas e distribuídas na área de estudo. Para o estudo da dieta foram coletadas fezes nas transeções e foram calculados as amplitudes dos nichos alimentares, as sobreposições de nichos, a freqüência relativa de ocorrência dos itens, a biomassa relativa consumida e o número relativo de indivíduos consumidos. Além disso, oito fazendas de silvicultura distribuídas no estado de São Paulo foram selecionadas para um levantamento rápido dos mamíferos de médio e grande porte por meio de armadilhamento fotográfico. Foram identificadas no Parque Ibiti 20 espécies incluindo uma doméstica. O Cerrado e a Floresta foram os ambientes com maior riqueza (n=15). No teste de Kruskal Wallis não houve diferença significativa entre os micro-ambientes borda, vegetação nativa e eucaliptais, tanto em termos de riqueza de espécies (H=1,82, df=2, p=0,402) quanto em número de detecções (H=0,37, df=2, p=0,833). Na avaliação do padrão de decréscimo de número de ocorrências, a diferença foi significativa no Cerrado (p=0,046). Mazama spp. foi a espécie mais abundante em todos os ambientes, apresentando maior abundância na Capoeira (1,45 detecções/10km percorridos) e a abundância geral no Parque foi 4,98 detecções/10km percorridos. O levantamento rápido nas oito fazendas de silvicultura resultou em 17 espécies registradas, incluindo uma doméstica. O número de espécies em cada fazenda variou de três a sete. Foram obtidas 621 fotografias e destas 33 foram de oito espécies de mamíferos, resultando em 4,5% de sucesso de captura. A Fazenda Globo I apresentou maior abundância relativa (7,33 detecções/10km). Foram analisadas 143 fezes e seis carnívoros foram identificados: Cerdocyon thous, Chrysocyon brachyurus, Leopardus pardalis, L. tigrinus, L. wiedii e Puma yagouaroundi Os itens identificados (n=44) foram distribuídos em seis grupos principais: material vegetal (37%), mamíferos (33%), invertebrados (17%), aves (5%), répteis (5%) e não alimentar (0,42%). O material vegetal foi mais freqüente na dieta do C. brachyurus e do C. thous (47% e 46%, respectivamente). Os mamíferos foram mais freqüentes na dieta dos felinos: P. yagouaroundi (54%), L. pardalis (39%), L. wiedii (49%) e L. tigrinus (38%). A menor amplitude de nicho total foi do C. brachyurus (BA=0,252). A maior sobreposição de nicho foi entre C. brachyurus e C. thous (Ojk =0,9706). Cavia aperea (58%) representou a maior biomassa relativa total consumida e Calomys tener (36%) o maior número relativo total de indivíduos consumidos. Os resultados demonstram que regiões de silvicultura, quando preservam áreas de vegetação nativa, podem fornecer abrigo, alimento, água e também permitir o fluxo gênico das espécies que dela se utilizam, aumentando a importância da implantação do manejo sustentável nessas regiões. / The diet of carnivores and the use of space by medium and large sized mammals were studied at Parque Ibiti (17.434 ha). This area involves farms of eucalyptus reforestation in the cities of Itararé and Itapeva, São Paulo. The data were collected in three different environments Cerrado (Brasilian Savanna), Ombrophylous Mixed Forest (Forest), and Ombrophylous Mixed Forest of secondary growth (Capoeira) from September 2004 to February 2006. The method of scats collection and calculation of breadth and overlap niche, relative frequency of occurrence, relative biomass consumed, and relative number of consumed individuals in transects determined dietary habit of carnivores. The survey of use of space identified the species through their visual contacts, tracks and remains in pre established transects distributed in area under study. Besides this, eight silvicultural farms in the state of São Paulo were selected for a quick survey on medium and large sized mammals using camera traps. Twenty species were identified at Parque Ibiti, including a household animal. The Cerrado and the Forest were the richest in animal species (n=15). Kruskal Wallis test showed no statistically significant difference in micro-environments border, natural bush and eucalyptus for number of species (H=1.82, df=2, p=0.402) and number of occurrences (H=0.37, df=2, p=0.833). The assessment of decrease pattern in the number of occurrences was significant only in Cerrado (p=0.046). Mazama spp. was the most abundant species in all environments and its largest number was found in Capoeira (1.45 detections/10km run) and general abundance at Parque Ibiti with 4.98 detections/10km run. Seventeen species were detected (including a domestic one) in the quick survey at the eight silvicultural farms. The number of species per farm varied from three to seven. From the 621 photos, 33 were mammals in a result of 4.5% success of capture. Farm Globo I presented the greatest relative abundance (7.33 detections/10km run). Six carnivores were identified through the analysis of 143 feces: Cerdocyon thous, Chrysocyon brachyurus, Leopardus pardalis, L. tigrinus, L. wiedii and Puma yagouaroundi. The identified elements (n=44) were distributed in six groups: vegetal matter (37%), mammals (33%), invertebrates (17%), birds (5%), reptile (5%), and non feeding matter (0.42%). Vegetal matter was more frequent for C. brachyurus and for C. thous (47% and 46%, respectively). Mammals were most frequent in the diets of felines P. yagouaroundi (54%), L. pardalis (39%), L. wiedii (49%) and L. tigrinus (38%). The least niche breadth was for C. brachyurus (BA=0.252). The greatest niche overlap was for C. brachyurus and C. thous (Ojk =0.9706). Cavia aperea (58%) represented the greatest total relative biomass consumed and Calomys tener (36%) the greatest total relative number of consumed individuals. The results show that in silvicultural regions with areas of preserved natural vegetation may provide shelter, food, water, and genic flux of species inhabiting that space suggesting the importance of sustainable management in those regions.

A modernização da agricultura e o surgimento da silvicultura em sua gênese no início do século XX, no Estado de São Paulo, são abordados e analisados nesta pesquisa. Nossa hipótese é a de que a elite agrária, incluindo Edmundo Navarro de Andrade, considerado um ícone da silvicultura no país, possuía um projeto de modernização da agricultura que se servia de modelos europeus e norte-americanos. Podemos dizer que a elite agrária se impõe ao país porque tinha uma proposta política consistente, bem fundamentada cientificamente, atualizada em relação a outros países e articulada com outros setores da sociedade, tais como os políticos e a mídia, principalmente. São apresentados fatos que mostram que a modernização da agricultura foi um processo mundial, que o Brasil nela se insere elegendo a Europa como modelo intelectual e os Estados Unidos como exemplo concreto a ser imitado em suas realizações, sendo a Sociedade Paulista de Agricultura (SPA) a principal incentivadora no Estado de São Paulo. O governo de Jorge Tibiriçá (1905-1908), cujo secretariado era composto em sua totalidade por membros oriundos da SPA, foi seu primeiro implementador. Esta pode ser considerada a primeira experiência de aplicação da ciência como norteadora de uma política pública bem definida em relação à agricultura. A ferrovia é o principal agente da modernização no campo ao permitir a agricultura avançar para além de duzentos quilômetros do litoral e ao permitir a circulação de mercadorias, pessoas e idéias. Faz parte da agricultura moderna: o uso de princípios científicos e tecnologias na organização do trabalho agrícola; a diversificação da agricultura; a implantação de colônias para fixar o colono à terra, tornando-os pequenos proprietários; a pesquisa agrícola para produção ou adaptação de novos conhecimentos e o ensino agrícola - a reformulação da Escola Superior de Agricultura Luiz de Queiroz (ESALQ) é a grande realização deste governo. Navarro se insere neste processo desde o seu retorno ao Brasil após conclusão dos estudos na Europa, em 1903, produzindo conhecimento de natureza teórico-prático em diversos ramos da agricultura moderna, mas se sobressai ao implantar nos Hortos da Cia Paulista de Estradas de Ferro a silvicultura moderna para suprir a demanda de lenha e acalmar os críticos que a acusavam de destruir florestas numa velocidade vertiginosa. O encantamento geral despertado pela figura de Navarro se deve ao fato de os níveis de excelência alcançados em suas experiências muito tempo depois ainda não haviam sido superados. Entretanto, como conservacionista, podemos quando muito argumentar que nem mesmo na Cia Paulista de Estradas de Ferro sua empreitada foi satisfatória, pois ela nunca conseguira produzir mais de quarenta por cento da lenha que consumia, ou seja, mesmo com um "mar de eucaliptos" ainda continuava consumindo árvores e florestas naturais inteiras. / The modernization of agriculture and the emergence of Forestry in its genesis in the beginning of the Twentieth Century in the State of São Paulo are approached and analyzed in this work. The hypothesis is that the agrarian elite, including Edmundo Navarro de Andrade, considered an icon in Forestry in Brazil, possessed a project for the modernization of agriculture, which used European and North American patterns. We can state that the agrarian elite enforces itself in Brazil because it had a firm political proposal, well-based scientifically and updated compared to other countries and wellrelated to other sectors of the society, such as politicians and the media above all. Facts are presented showing that the modernization of agriculture is a worldwide process, in which Brazil follows Europe for an intellectual pattern and The United Sates of America as a concrete example to be imitated in its accomplishments, and the "Sociedade Paulista de Agricultura" (SPA) the main supporter in the State of São Paulo. The government of Jorge Tibiriçá (1905-1908), whose secretaries were in its majority members of the "Sociedade Paulista de Agricultura" (SPA), was its first supporter. This was the first experience of science application as a guide for a well-defined public politics regarding agriculture. The railroad is the main agent for the modernization of the fields, allowing the agriculture move more than two hundred kilometers from the seacoast and making the circulation of products, people and ideas possible. It is part of modern agriculture the use of scientific principals, technology in the organization of the agricultural work, the diversification of agriculture, the implantation of colonies to locate the farmer to the land, making them small land owners; the agricultural research for the production or adaptation of new knowledge and the agricultural teaching - the reformulation of the "Escola Superior de Agricultura Luiz de Queiroz (ESALQ) is the great accomplishment of this government. Navarro participates in this process since his return to Brazil, after having concluded his studies in Europe in 1903; producing theoretical/practical knowledge in different sections of agriculture, but he excels when he implants Modern Forestry in the "Hortos da Companhia Paulista de Estradas de Ferro", to supply the wood demand and calm down the critics that accused it of destroying forests in a wild speed. The general enchantment provoked by Navarro is due to the fact that the levels of excellence achieved in his experiments had not been surpassed after a long time. However, as a conservative, we can affirm that not even in the "Companhia Paulista de Estradas de Ferro" his work was satisfactory, for this company would never be able to produce more than forty percent of the wood it consumed, that means, even with a "sea of eucalyptus" it still devoured entire natural trees and forests.

L'évaluation de la durabilité écologique et économique d'une exploitation forestière dans le contexte amazonien est l'objectif de ce travail. Deux sites ont été utilisés : 1)le site de Paracou en Guyane française sur lequel la dynamique forestière est suivie depuis 1984; 2) une forêt privée située au Pará, Brésil, offrant des données sur l'impact de l'exploitation et ses coûts et recettes. Premièrement, ce travail a consisté à améliorer le simulateur de la dynamique forestière Selva. 11 modèles spécifiques aux processus de mortalité et de recrutement ont été élaborés. Les processus de mortalité sur pied et par chablis utilisent respectivement des variables biologiques de l'arbre et des variables descriptives du peuplement. Des variables décrivant la structure et la composition floristique du peuplement ont permis de modéliser le recrutement de 30 espèces, surtout des pionnières/héliophiles. L'incorporation de ces modèles a permis d'intégrer 92 stratégies de vie dans le simulateur. La forêt virtuelle générée montre une structure et une diversité spécifique proches d'une forêt primaire. Dans le cadre de la législation brésilienne préconisant des cycles de 25-35ans, la simulation montre qu'il est possible d'exploiter 4 tiges/ha/cycle en maintenant une surface terrière 20% inférieure à l'originale. Si l'exploitation forestière engendre des bénéfices variant entre 147 et 239 US$/ha/an, la déforestation produit des bénéfices légèrement supérieurs (295 US$/ha/an). Un schéma de compensation financière de changement d'un système émetteur de carbone (déforestation) pour un autre (exploitation forestière) représenterait un coût d'abattement de la tonne du carbone supérieur à US$ 10

Butternut (Juglans cinerea L.), a lesser-known relative of black walnut (Juglans nigra L.), is a native tree species beneficial for wildlife, valuable for timber, and part of the great diversity of species in the eastern forests of North America. Populations of butternut are being devastated by butternut canker disease, caused by the fungus Sirococcus clavigignenti-juglandacearum (V.M.G. Nair, Kostichka, & Kuntz), which is thought to be introduced to North America. The disease causes multiple branch and stem cankers that eventually girdle trees. Small population sizes, lack of sprouting, and shade intolerance exacerbates the disease and results in permanent losses of butternut across the native range. Fortunately, healthy, canker-free butternut trees have been found proximal to diseased trees, indicating that a breeding approach could be a feasible strategy for producing and reintroducing resistant butternuts. A successful restoration program will require an understanding of genetic variation in open-pollinated seedlings, genetic basis of disease resistance, seedling establishment procedures, site requirements, and a greater understanding of disease development over time. This dissertation is divided into six parts, with the overall goal of insight into butternut ecology and management techniques which could be used to guide restoration decisions for this important species. The first two parts are an introduction and a literature review. In the third section, butternut seedlings were propagated in nursery progeny plantings to determine the genetic and phenotypic variability among one-year-old seedlings in a controlled environment. Part four outlines the disease development of butternut seedlings across progeny in resistance screening plantings at various locations. Part five aims at aiding restoration techniques by determining the impact of phenotypic and genetic variables on establishment success across various planting sites with different silvicultural treatments. Part six describes the dynamics of a large population of healthy and diseased butternut trees including disease development across temporal scales. The information gained from this research will be directly used in gene conservation strategies, the construction of disease resistant breeding orchards, and in determining appropriate restoration techniques.