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Forests have been proposed as a means of reducing atmospheric carbon dioxide levels due to their ability to store carbon as biomass. To quantify the amount of atmospheric carbon sequestered by forests, biomass and density estimates are often needed. This study develops, implements, and tests an individual tree-based algorithm for obtaining forest density and biomass using orthophotographs and small footprint LiDAR imagery. It was designed to work with a range of forests and image types without modification, which is accomplished by using generic properties of trees found in many types of images. Multiple parameters are employed to determine how these generic properties are used. To set these parameters, training data is used in conjunction with an optimization algorithm (a modified Nelder-Mead simplex algorithm or a genetic algorithm). The training data consist of small images in which density and biomass are known. A first test of this technique was performed using 25 circular plots (radius = 15 m) placed in young pine plantations in central Virginia, together with false color othophotograph (spatial resolution = 0.5 m) or small footprint LiDAR (interpolated to 0.5 m) imagery. The highest density prediction accuracies (r2 up to 0.88, RMSE as low as 83 trees / ha) were found for runs where photointerpreted densities were used for training and testing. For tests run using density measurements made on the ground, accuracies were consistency higher for orthophotograph-based results than for LiDAR-based results, and were higher for trees with DBH ≥10cm than for trees with DBH ≥7 cm. Biomass estimates obtained by the algorithm using LiDAR imagery had a lower RMSE (as low as 15.6 t / ha) than most comparable studies. The correlations between the actual and predicted values (r2 up to 0.64) were lower than comparable studies, but were generally highly significant (p ≤ 0.05 or 0.01). In all runs there was no obvious relationship between accuracy and the amount of training data used, but the algorithm was sensitive to which training and testing data were selected. Methods were evaluated for combining predictions made using different parameter sets obtained after training using identical data. It was found that averaging the predictions produced improved results. After training using density estimates from the human photointerpreter, 89% of the trees located by the algorithm corresponded to trees found by the human photointerpreter. A comparison of the two optimization techniques found them to be comparable in speed and effectiveness. / Ph. D.

Accurate prediction of mortality is an important component of forest growth and yield prediction systems, yet mortality remains one of the least understood components of the system. Whole-stand and individual-tree mortality models were developed for loblolly pine plantations throughout its geographic range in the United States. The model for predicting stand mortality were developed using stand characteristics and biophysical variables. The models were constructed using two modeling approaches. In the first approach, mortality functions for directly predicting tree number reduction were developed using algebraic difference equation method. In the second approach, a two-step modeling strategy was used where a model predicting the probability of tree death occurring over a period was developed in the first step and a function that estimates the reduction in tree number was developed in the second step. Individual-tree mortality models were developed using multilevel logistic regression and survival analysis techniques. Multilevel data structure inherent in permanent sample plots data i.e. measurement occasions nested within trees (e.g., repeated measurements) and trees nested within plots, is often ignored in modeling tree mortality in forestry applications. Multilevel mixed-effects logistic regression takes into account the full hierarchical structure of the data. Multilevel mixed-effects models gave better predictions than the fixed effects model; however, the model fits and predictions were further improved by taking into account the full hierarchical structure of the data. Semiparametric proportional hazards regression was also used to develop model for individual-tree mortality. Shared frailty model, mixed model extension of Cox proportional hazards model, was used to account for unobserved heterogeneity not explained by the observed covariates in the Cox model. / Ph. D.

Sweetgum, Liquidambar styraciflua, is a diffuse-porous hardwood occurring in the southeastern United States. In this observational study, trees from two plantations of sweetgum were evaluated for mechanical properties. The two plantations were similar in age, soil type, competition control, and water availability, but differed in nutrient availability, growing season, and growth rate. Three trees representing different crown classes were removed from both plantations. Each tree was sampled for compression strength parallel to grain along the height of the merchantable stem. Oven-dry specific gravity was then calculated for each sample. The results indicate that young sweetgum trees grow weaker wood than mature trees. It was observed that dominant trees were stronger and denser than other trees. Denser wood was formed in the plantation with the shortest growing season and smallest growth rate. Three of six trees showed significant correlations of strength and stiffness with height in the tree. / Master of Science

Les plantations d'Eucalyptus, au Congo (région de Pointe-Noire) comme au Maroc (forêt de la Maâmora), soulèvent des controverses quant à leurs effets sur des sols sableux pauvres en matière organique. Dans un enjeu de développement durable de tels écosystèmes anthropiques, les recherches sur le sujet se sont multipliées. Toutefois, les connaissances relatives au fonctionnement biologique des sols sous ces plantations méritent encore d'être approfondies. Principaux acteurs de ce fonctionnement biologique, les organismes vivant dans ces sols et leurs activités ne sont que trop peu décrites, et nécessitent en ce sens de se trouver au cœur des études sur le sujet. Notre travail de thèse s'inscrit dans ces problématiques. Ainsi, nous évaluons les conséquences du reboisement sur les communautés de la macrofaune et des microorganismes de ces sols, et également l'activité des enzymes clés liées aux principaux cycles biogéochimiques (C, N et P).Cette recherche présente la particularité de la prise en compte simultanée de deux facteurs peu souvent évoqués, que sont, l'« âge des plantations » et la « profondeur du sol ». Nous avons abordé ces questions par une étude multi-échelle.Ainsi, nous avons étudié les macroinvertébrés quant à leur diversité taxonomique et à leur composition verticale, selon une approche combinée (TSPF + carré anglais). Par la suite, les premières caractérisations de structure et de diversité des communautés microbiennes ont été réalisées. Ceci, par mesure de densité et par déterminations morphotypiques (cultures in vitro) et génétiques (DGGE), au niveau des communautés totales. Par mesure du potentiel métabolique pour ce qui est des communautés fonctionnelles (plaques Biolog). Enfin, l'activité biologique des sols a été évaluée en mesurant l'activité de huit enzymes et l'activité microbienne globale (hydrolyse FDA).Ainsi, par comparaison à la forêt naturelle adjacente, cette étude nous a permis de mettre en évidence que l'introduction d'eucalyptus sur savane (Congo) ou sur chêne-liège dégradé (Maroc), modifie la structure et la diversité des communautés de la macrofaune et des microorganismes du sol ainsi que le profil des activités enzymatiques. Aussi bien en fonction de l'âge des plantations que de la profondeur du sol, ceci est valable. C'est le fonctionnement biologique qui se trouve donc impacté.Les proportions et les conséquences de cet impact restent toutefois particulières à chaque cas. Il faut cependant noter exception pour les activités enzymatiques liées au cycle de l'azote, qui apparaissent influencées de façon comparable dans les deux cas à l'étude. Ces activités diminuent significativement avec l'âge du peuplement, confirmant le statut déficitaire en azote de ce type de plantation. / Eucalyptus plantations in Congo (Pointe-Noire region) and in Morocco (Mamora forest) raised certain controversies regarding their effects on the sandy poor soils. In such anthropogenic ecosystems, researches on the subject have multiplied in order to ensure their sustainable management. However, knowledge on the biological functioning of soils in these plantations still needs to be explored. Main actors of this biological functioning are soil organisms and their activities which have been described very little, and need to be more studied. Our thesis encompasses this problematic. Therefore, we evaluated the impact of reforestation on the communities of macrofauna and microorganisms of soil, and the activity of different key enzymes, as well, related to main biogeochemical cycles (C, N and P). This research presents, particularly, a simultaneous consideration of two factors rarely mentioned before: the "age of the plantations" and "soil depth". We addressed these issues by a multi-scale study. We studied macroinvertebrates by their taxonomic diversity and vertically composition by a combined approach (TSPF + English square). Subsequently, the characterization of structure and diversity of microbial communities was done by density measurements, morphotype-specific (in-vitro culture) and the genetic determinations (DGGE) and by measuring the metabolic potential in terms of functional communities (Biolog plates). Finally, soil biological activity was evaluated by determining the activity of eight different enzymes and the total microbial activity (FDA hydrolysis).Therefore, as compared to the adjacent natural forest soils, this study allowed us to demonstrate that the introduction of eucalyptus plantations, in savanna (Congo) or in degraded cork oak ecosystem (Morocco), alters the structure and diversity of macrofauna communities, soil microorganisms and the enzymatic activity profiles. Consequently, the biological functioning of the soils is impacted both in terms of the age of plantations and soil depth. However, the proportions and the consequences of this impact were very specific in each case, with the exception of enzymatic activities related to the nitrogen cycle, which influenced comparatively in both studies. These activities decreased significantly along with the stand age of eucalyptus plantations, confirming the deficient status of nitrogen in such plantations.

The present study investigates new frontiers of lidar technology knowledge assessessing of tropical forest degradation and restoration. The thesis is structured with an introductory chapter, four technical chapters, which explored technical and scientific aspects of the application of lidar technology to the evaluation of forest degradation in the Amazon and restoration of forests in the Atlantic Forest, and a final chapter with considerations and a summary of the main scientific results obtained in this thesis. The results of chapter 2 provided important insights for the correct modeling of leaf area density (LAD) proflies profiles usind airborne lidar. LAD profile is the decomposition of the leaf area index (LAI) along the vertical canopy profile and can be used to answer many ecological questions. The results of chapter 2 provided important insights for the correct modeling of LAD profiles. Chapter 3, using lidar data on aerial and portable ground platforms, in the Biological Dynamics of Forest Fragments Project (BDFFP), demonstrated in an unprecedented way the effect of forest fragmentation in the canopy structure (lidar-derived) and their relationships with the change of the tree community. In this chapter, the results showed that the lidar technology has enormous potential to monitor the impact of forest fragmentation in a high precision scale for large areas. Chapter 4, using data from several forest typologies in the Atlantic Forest biome restoration collect by a portable ground lidar system, demonstrated the potential of canopy structural attributes to distinguish different forest typologies and to estimate above ground woody dry biomass. However, the results were not positive for estimating tree community diversity (richness, Shannon index and species composition). Finally, chapter 5 demonstrated the potential of a novel lidar system on a drone platform (also known as UAV - unmanned aerial vehicle) to monitor forest restoration plantations. Lidar is revolutionizing the way we measure forest landscapes and can be an indispensable tool for the success of forest restoration projects, having the potential to support on planning, monitoring and inspection of forest restoration landscapes. In this thesis, we demonstrate several applications of remote sensing to address the context of forest restoration, and we established methodological bases for other studies to expand the use of this technology for decision making in tropical forest conservation, management and restoration. / O presente estudo investiga novas fronteiras do conhecimento da aplicação da tecnologia de sensoriamento remoto lidar à avaliação da degradação e restauração de florestas tropicais. A tese está estruturada na forma de um capítulo de introdução, quatro capítulos técnicos, que exploraram aspectos técnicos e científicos da aplicação da tecnologia lidar à avaliação da degradação de florestas na Amazônia e restauração de florestas na Mata Atlântica, e de um capítulo final com considerações gerais e uma síntese dos principais resultados científicos obtidos nesta tese. O capítulo 2, utilizando dados lidar aeroembarcados em avião, analisou uma questão técnica, sobre a influência da densidade de pulsos da nuvem lidar e da resolução de amostragem para a modelagem do perfil de densidade de áerea foliar em florestas tropicais (DAF). O perfil de DAF é a decomposição do índice de área foliar (IAF) ao longo do perfil vertical do dossel e pode ser utilizado para responder diversas questões ecológicas. Os resultados da capítulo 2 trouxeram importantes insights para a correta modelagem dos perfis de DAF. O capítulo 3, utilizando dados lidar em plataformas aeroembarcados e terrestre portátil, no Projeto Dinâmica Biologica de Fragmentos Florestais (PDBFF), demonstrou de maneira inédita o efeito da fragmentação florestal sobre a alteração da estrutura do dossel (derivados de dados lidar) e suas relações com a mudança da comunidade arbórea. Neste capítulo os resultados demonstraram que a tecnologia lidar tem enorme potencial para monitorar o impacto da fragmentação florestal para grandes áreas e em fina escala. O capítulo 4, utilizando dados de diversas tipologias florestais em restauração no bioma Mata Atlântica, a partir de um sistema lidar terrestre portátil, demonstrou a capacidade dos atributos estruturais do dossel em distinguir diferentes tipologias florestais, estimar diversidade e biomassa de madeira acima do solo. Contudo, os resultados não foram muito positivos para estimativa da diversidade da comunidade arbórea (riqueza, indice de Shannon e composição de espécies). Finalmente, o capitulo 5 demonstrou a capacidade de um sistema inovador lidar aeroembarcado em uma plataforma drone (também conhecida como VANT - veículo aéreo não tripulado) para monitorar plantios de restauração florestal. O lidar está revolucionando a maneira de mensurarmos as paisagens florestais, podendo ser uma ferramenta imprecindível para o sucesso dos projetos de restauração florestal em larga escala, tendo o potencial de auxiliar desde o planejamento ao monitoramento e fiscalização dos projetos florestais. Nesta tese, demonstramos diversas aplicações do sensoriamento remoto lidar ao contexto da restauração florestal, e estabelecemos bases metodológicas para que outros estudos expandam o uso desta tecnologia para tomada de decisão na conservação, manejo e restauração de florestas tropicias.

Essa pesquisa buscou avaliar os efeitos da utilização de três diferentes sistemas de colheita florestal na dinâmica, estrutura e diversidade da regeneração natural, em talhão abandonado de Eucalyptus saligna Smith. O estudo foi realizado em área pertencente à Estação Experimental de Ciências Florestais da ESALQ-USP, no município de Itatinga/SP. A área amostral total é de 3,24 ha, sendo instalada em talhão abandonado há cerca de 40 anos, e que sofreu técnicas de colheita para extração de madeira há cerca de 2 anos atrás. O delineamento experimental aplicado foi o de blocos ao acaso que já fora utilizado em estudo realizado por Mendes (2012) na área. Para cada tratamento foi instalada 3 parcelas de 30 x 30 m em cada bloco, totalizando 9 parcelas por tratamento em uma área amostral de 0,81 ha por tratamento. Foi realizado um inventário da população de Eucalyptus saligna, bem como o levantamento fitossociológico de toda a regeneração natural H >= 1,30 m e DAP > 5,0 cm. Em sub-parcelas de 3x3 metros foram contados e plaqueados todos os indivíduos com H >= 0,50 m e DAP < 5,0 cm. Na testemunha foram mensurados 278 indivíduos de Eucalyptus saligna, apresentando uma densidade absoluta de 343,21 ind./ha. O volume total de eucalipto encontrado foi de 438,72 m3.ha-1 e a área basal total de 23,18 m2.ha-1. Nas 36 parcelas foram amostrados 1910 indivíduos, distribuídos em 168 espécies, pertencentes a 78 gêneros e 39 famílias. A densidade total estimada foi de 589,51 indivíduos por hectare para a classe de indivíduos da regeneração natural com DAP >= 5,0 cm e de 11.080 indivíduos/ha para a regeneração natural com DAP < 5,0 cm e H >= 0,50 m. As variáveis para o estudo dos efeitos na estrutura da vegetação foram quatro classes de danos em árvores: intactas, danificadas, rebrotadas e mortas. Em relação às classes de danos estruturais causados na vegetação, nota-se que não houve diferença significativa entre a colheita convencional e a colheita de impacto reduzido 2. Os melhores valores em termos de árvores intactas foram encontrados na colheita de impacto reduzido 1 (57,89%) e na testemunha (93,83%), no entanto estes tratamentos diferenciaram-se significativamente entre si. Para as árvores mortas, a menor taxa foi encontrada na testemunha (4,23%), seguida da colheita de impacto reduzido 1 com uma taxa de 16,98%. Avaliou-se a diversidade de espécies nativas cujo DAP >= 5,0 cm, através da análise do índice de diversidade de Shannon(H\'), riqueza de espécies (S) e equabilidade de Pielou (J\'). Foram calculadas as taxas de dinâmicas: mortalidade, recrutamento, ganho e perda em área basal, as taxas de rotatividade e as taxas de mudança líquida no período. A remoção total dos Eucaliptos plantados aumentou o recrutamento em comparação com a área controle (sem intervenção), no entanto, a diversidade de espécies foi maior na área controle (sem intervenção). A testemunha foi o único tratamento que apresentou diferença significativa entre o índice de diversidade de Shannon e a riqueza para o período comparado (logo após a colheita e após os 24 meses). / This work aimed to evaluate the effect of three fallow systems in natural regeneration dynamics, structure and diversity in an abandoned plantation of Eucalyptus saligna Smith. Our study was carried out in the Itatinga Experimental Station of the University of São Paulo - USP, located in the county of Itatinga-SP, Brazil. The plantation has been abandoned for approximately 40 years; however, remaining E. saligna individuals were removed two years before our study under different harvesting systems. We used the randomized blocks design to sample 3.24 hectares in the study area. For each treatment, we placed three 30 x 30 m plots in each block totaling nine plots per treatment and a sampling area of 0.81 hectares per treatment. We sampled all E. saligna individuals, as well as natural regeneration with height >= 1.3 m and DBH >= 5,0 cm. In 3 x 3 m subplots we counted and tagged all individuals with height >= 5 cm and DBH < 5,0 cm. In the Control plots we found 278 individuals of E. saligna, which represents a density of 343.21 individuals/hectare. Total estimated wood volume of E. saligna was of 438,72 m3.ha-1, with a basal area of 23,18 m2.ha-1. In the 36 plots we sampled 1910 individuals, distributed in 168 species, 78 genus and 39 families. Natural regeneration density was of 589.51 individuals/hectare for individuals DBH > 5.0 cm and 11.080 individuals/hectare for individuals DBH < 5.0 cm and height >= 0.5 m. We studied the effect of fallow system in the vegetation structure considering four classes of damage to natural regeneration: intact, damaged, resprouted and dead. Our study shows that there was no significant difference between Conventional and Reduced Impact Logging 2 systems. The Reduced Impact Logging 1 and Control plots showed higher proportion of intact trees (57.89 % and 93.83 %, respectively), however, these treatments differed among each other. Control plots showed the lowest proportion of dead trees, followed by Reduced Impact Logging 1 (4.23 % and 16.98 %, respectively). We evaluated diversity of native individuals with DBH >= 5.0 cm through the Shannon diversity index (H\'), species richness (S) and Pielou equability (J\'). We calculated the dynamic rates ofmortality, recruitment, change in basal area, turnover and net change rates during the study period. Removal of planted E. saligna increased recruitment when compared to Control plots, however species diversity was higher in Control plots. Control plots were the only treatment that showed significant differences between the Shannon diversity Index and richness for the study period (i.e. right after logging and 24 months after logging).

Este trabalho contribui para a evolução dos métodos que lidam com a quantificação de biomassa em plantações florestais em grande escala. Mais especificamente, explora o potencial de novos métodos baseados em sistemas de escaneamento a laser aerotransportado (ALS) que produzem uma representação 3D da estrutura vertical e horizontal acima do solo em plantios de Eucalyptus spp. A abordagem assume que a biomassa acima do solo pode ser estimada de forma precisa quando o perfil vertical da altura do dossel e a área basal são bem conhecidos. Assim, quatro questões foram analisadas: (i) se a função de densidade probabilidade Weibull com dois parâmetros (escala ? e forma ?) consegue descrever com precisão a distribuição vertical de pontos gerada pela tecnologia ALS e gerar um perfil aparente de altura de dossel adequado em plantios de eucalipto; (ii) se quando gerada por tecnologia ALS, a proporção de retornos no subdossel e solo tem relação significativa e positiva com a variável área basal; (iii) qual a qualidade da predição de área basal e de biomassa seca de lenho quando são usadas como variáveis explicativas um percentil baixo de altura da nuvem ALS e o parâmetro de escala da distribuição Weibull ajustada para definir o perfil vertical do dossel; e (iv) qual a qualidade dos mapas de biomassa de lenho de plantios de eucaliptos quando produzidos a partir de dois métodos diferentes, um de interpolação de dados das parcelas de campo (krigagem ordinária) e outro que usa a nuvem de pontos ALS para calibrar as informações das parcelas de campo (regressão linear). Os resultados mostraram que a função Weibull de dois parâmetros ajustou com precisão adequada o perfil das alturas do plantio de eucalipto. Do ponto de vista prático, esse resultado reforça as estratégias de uso dos parâmetros da função Weibull (escala e forma) como métricas que caracterizam adequadamente a estrutura vertical dos povoamentos florestais. A estimativa de área basal em função da proporção de retornos no subdossel e no solo mostrou-se moderada (R² = 0.42 e rRMSE = 7.6%), sendo necessários mais estudos que investiguem essa relação. As predições de área basal e biomassa do lenho foram aprimoradas em função do parâmetro ? da função Weibull, usado como estimador de escala para as alturas do dossel (área basal, R² = 0.77 e rRMSE = 4.8% e biomassa do lenho, R² = 0.89 e rRMSE = 5.1%). As variáveis, percentil 30 e parâmetro de forma (?) da função Weibull, também produziram boas estimativas (R² = 0.82 para área basal e R² = 0.93 para biomassa de lenho). Os mapas de predição de biomassa de lenho mostraram-se mais precisos quando derivados a partir de dados ALS (rRMSE = 5.5% versus 12.7% na interpolação por krigagem ordinária). / This work contributes to the evolution of methods dealing with the quantification of biomass in large-scale forest plantations. More specifically, it explores the potential of new methods based on airborne laser scanning systems to produce a 3D representation of the vertical and horizontal structure of above ground Eucalyptus spp plantations. The approach assumes that above ground biomass can be precisely estimated when the vertical profile of canopy heights and basal area are well known. Thus, four questions are examined: (i) can the Weibull probability density function (pdf) with two parameters (? scale and ? shape) describe accurately the vertical distribution of points generated by the ALS technology and generate an adequate apparent profile of canopy heights for the eucalyptus plantation?; (ii) when generated by the ALS technology, is the proportion of understory returns to ground returns significantly and positively related with basal area?; (iii) how well are basal area and dry stem biomass predicted by models using low height percentile values of the ALS point cloud and the scale parameter of the Weibull distribution describing the vertical canopy profile?; and (iv) how accurate are stem biomass maps of the eucalyptus plantation when two different methods are used, one based on interpolation that uses sample plots information (ordinary kriging) and another that uses the ALS point cloud to calibrate the sample plot information (linear regression)? The results showed that the Weibull pdf with two parameters fitted with adequate accuracy the plantation\'s height profiles. From a practical standpoint, this result reinforces the strategies of using the Weibull parameters (scale and shape) as metrics that adequately characterize the vertical structure of forest stands. Basal area estimates derived from the proportion of understory and ground returns presented only moderated accuracy (R² = 0.42 e rRMSE = 7.6%) and more research is needed to investigate such relationship. Good results were obtained when basal area and stem biomass were fitted as a function of the Weibull ? parameter, as a proxy for the scale of canopy heights (basal area, R² = 0.77 e rRMSE = 4.8%, and stem biomass, R² = 0.89 and rRMSE = 5.1%). The explanatory variables percentile 30 and the Weibull shape parameter (?) also produced good estimates (R² = 0.82 for basal area and R² = 0.93 for stem biomass). Stem biomass prediction maps showed to be more accurate when derived from ALS data (rRMSE = 5.5% against 12.7% derived from ordinary kriging interpolation).

As florestas plantadas contribuem para o desenvolvimento econômico, social e ambiental brasileiro, e o setor florestal busca plantios cada vez mais produtivos e melhor aproveitados. A tecnologia a laser aerotransportada (ALS - Airborne Laser Scanning), capaz de gerar informações tridimensionais precisas em extensas áreas e em pequeno intervalo de tempo, tem se destacado nas aplicações florestais, sendo utilizada na quantificação e caracterização de florestas. Neste estudo foram utilizados dados ALS obtidos em dois sobrevoos (2013 e 2014), cobrindo uma área de plantio do gênero Eucalyptus com diferentes clones e idades, localizada no estado de São Paulo. Esta dissertação é dividida em três partes. A primeira buscou avaliar a combinação de métricas ALS e de dupla amostragem nas estimativas de volume e na redução da intensidade amostral, comparando seus resultados aos de métodos amostrais tradicionais. Os resultados mostraram que a dupla amostragem obteve o menor erro de amostragem dentre os delineamentos, permitindo a redução do esforço amostral. A segunda parte visou caracterizar as diferenças estruturais existentes entre clones de eucalipto, com diferentes idades, a partir de métricas ALS e perfis de altura do dossel (CHP). O estudo mostrou que é possível distinguir a estrutura do dossel dos clones, o que pode contribuir com melhorias nas estimativas e no gerenciamento dos plantios comerciais. Na última parte, foram avaliados dois algoritmos de detecção de árvores individuais quanto à quantificação dos indivíduos e os efeitos da composição (tamanho de célula e filtragem) do modelo digital de alturas (CHM) no desempenho desses algoritmos. Verificou-se que as características do CHM influenciam na detecção. A estratégia com melhor desempenho resultou em um erro médio relativo de 11% no número de indivíduos. / Planted forests contribute to the economic, social and environmental development of Brazil, and the forest industry aims to increase productivity and the efficient use of these plantations. Airborne Laser Scanning (ALS) technology, capable of generating accurate three-dimensional information, covering large areas in a short time, has highlighted potential in forestry applications and has been applied in forests quantification and characterization. In this study, ALS data were obtained from two flights (2013 and 2014), covering a Eucalyptus plantation area with different clones and ages, in the state of São Paulo. This thesis comprises three parts. The first study aimed to evaluate the combination of ALS metrics and double sampling design for volume estimates and reducing sampling intensity, comparing the results to traditional sampling methods. Results showed that the double sampling had the lowest error from the designs, allowing the reduction of the sampling effort. The second part was proposed to characterize the structural differences between Eucalyptus clones with different ages, based on metrics ALS and canopy height profiles (CHP). The study showed that it is possible to distinguish the canopy structure of the clones, which can contribute to improvements in estimates and management of commercial plantations. In the last study, two individual tree detection algorithms were evaluated for quantification of individuals, and the effect of the canopy height model (CHM) composition at the performance of these algorithms was analyzed. It was found that the CHM characteristics influence the tree detection. The strategy with better performance resulted in an average relative error of 11% in number of trees.

The present study investigates new frontiers of lidar technology knowledge assessessing of tropical forest degradation and restoration. The thesis is structured with an introductory chapter, four technical chapters, which explored technical and scientific aspects of the application of lidar technology to the evaluation of forest degradation in the Amazon and restoration of forests in the Atlantic Forest, and a final chapter with considerations and a summary of the main scientific results obtained in this thesis. The results of chapter 2 provided important insights for the correct modeling of leaf area density (LAD) proflies profiles usind airborne lidar. LAD profile is the decomposition of the leaf area index (LAI) along the vertical canopy profile and can be used to answer many ecological questions. The results of chapter 2 provided important insights for the correct modeling of LAD profiles. Chapter 3, using lidar data on aerial and portable ground platforms, in the Biological Dynamics of Forest Fragments Project (BDFFP), demonstrated in an unprecedented way the effect of forest fragmentation in the canopy structure (lidar-derived) and their relationships with the change of the tree community. In this chapter, the results showed that the lidar technology has enormous potential to monitor the impact of forest fragmentation in a high precision scale for large areas. Chapter 4, using data from several forest typologies in the Atlantic Forest biome restoration collect by a portable ground lidar system, demonstrated the potential of canopy structural attributes to distinguish different forest typologies and to estimate above ground woody dry biomass. However, the results were not positive for estimating tree community diversity (richness, Shannon index and species composition). Finally, chapter 5 demonstrated the potential of a novel lidar system on a drone platform (also known as UAV - unmanned aerial vehicle) to monitor forest restoration plantations. Lidar is revolutionizing the way we measure forest landscapes and can be an indispensable tool for the success of forest restoration projects, having the potential to support on planning, monitoring and inspection of forest restoration landscapes. In this thesis, we demonstrate several applications of remote sensing to address the context of forest restoration, and we established methodological bases for other studies to expand the use of this technology for decision making in tropical forest conservation, management and restoration. / O presente estudo investiga novas fronteiras do conhecimento da aplicação da tecnologia de sensoriamento remoto lidar à avaliação da degradação e restauração de florestas tropicais. A tese está estruturada na forma de um capítulo de introdução, quatro capítulos técnicos, que exploraram aspectos técnicos e científicos da aplicação da tecnologia lidar à avaliação da degradação de florestas na Amazônia e restauração de florestas na Mata Atlântica, e de um capítulo final com considerações gerais e uma síntese dos principais resultados científicos obtidos nesta tese. O capítulo 2, utilizando dados lidar aeroembarcados em avião, analisou uma questão técnica, sobre a influência da densidade de pulsos da nuvem lidar e da resolução de amostragem para a modelagem do perfil de densidade de áerea foliar em florestas tropicais (DAF). O perfil de DAF é a decomposição do índice de área foliar (IAF) ao longo do perfil vertical do dossel e pode ser utilizado para responder diversas questões ecológicas. Os resultados da capítulo 2 trouxeram importantes insights para a correta modelagem dos perfis de DAF. O capítulo 3, utilizando dados lidar em plataformas aeroembarcados e terrestre portátil, no Projeto Dinâmica Biologica de Fragmentos Florestais (PDBFF), demonstrou de maneira inédita o efeito da fragmentação florestal sobre a alteração da estrutura do dossel (derivados de dados lidar) e suas relações com a mudança da comunidade arbórea. Neste capítulo os resultados demonstraram que a tecnologia lidar tem enorme potencial para monitorar o impacto da fragmentação florestal para grandes áreas e em fina escala. O capítulo 4, utilizando dados de diversas tipologias florestais em restauração no bioma Mata Atlântica, a partir de um sistema lidar terrestre portátil, demonstrou a capacidade dos atributos estruturais do dossel em distinguir diferentes tipologias florestais, estimar diversidade e biomassa de madeira acima do solo. Contudo, os resultados não foram muito positivos para estimativa da diversidade da comunidade arbórea (riqueza, indice de Shannon e composição de espécies). Finalmente, o capitulo 5 demonstrou a capacidade de um sistema inovador lidar aeroembarcado em uma plataforma drone (também conhecida como VANT - veículo aéreo não tripulado) para monitorar plantios de restauração florestal. O lidar está revolucionando a maneira de mensurarmos as paisagens florestais, podendo ser uma ferramenta imprecindível para o sucesso dos projetos de restauração florestal em larga escala, tendo o potencial de auxiliar desde o planejamento ao monitoramento e fiscalização dos projetos florestais. Nesta tese, demonstramos diversas aplicações do sensoriamento remoto lidar ao contexto da restauração florestal, e estabelecemos bases metodológicas para que outros estudos expandam o uso desta tecnologia para tomada de decisão na conservação, manejo e restauração de florestas tropicias.