Temperate forests are an important carbon sink, yet there is uncertainty regarding land-use history effects on biomass accumulation and carbon storage potential in secondary forests. Understanding long-term biomass dynamics is important for managing forests as carbon sinks and for co-benefits such as watershed protection and biodiversity. However there are many unanswered questions regarding these dynamics in northeastern U.S. forests: How have secondary forests of the U.S. Northeast recovered post nineteenth century agricultural abandonment? How has the region's extensive land-use history influenced long-term structural development and aboveground carbon storage? To answer these questions, we employed a longitudinal study based on twelve years of empirical data (2001-2013) from the Marsh-Billings-Rockefeller (MBR) National Historical Park in Woodstock, VT. MBR Park was the first parcel of land to actively be reforested in the eastern U.S., and as such, its diverse forest mosaic reflects a history of alternate reforestation approaches and varied successional trajectories indicative of secondary forest recovery occurring across the broader northeastern forest landscape. We also used 150 years of documentary data from park management records. This research evaluates the effects of reforestation approaches (planting vs. natural regeneration), management regimes (long-term low-to-intermediate harvest intensities at varied harvest frequencies), and stand development pathways on biomass outcomes. We generated biometrics representative of stand structural complexity, including the H' structural diversity index, and aboveground biomass (live trees, snags, and downed coarse woody debris pools) estimates. Multivariate analyses evaluated the predictive strength of reforestation approach, management history, and site characteristics relative to aboveground carbon pools and stand structural complexity. Classification and Regression Tree (CART) analysis ranked reforestation approach (plantation or natural regeneration) as the strongest predictor of long-term mean total aboveground carbon storage, while harvest frequency, and stand age were selected as secondary variables. CART ranked forest percent conifer (a metric closely associated with reforestation approach) as the strongest predictor of H' index, while harvest intensity, and harvest frequency were selected as secondary variables. Increases in harvest intensity can significantly reduce aboveground carbon storage. Our results suggest that a variety of long-term recovery pathways converge on high levels of aboveground carbon storage, including both conifer plantations and naturally regenerated hardwood stands, but choice of silvicultural management approach can dramatically alter those trajectories. Importantly, total aboveground biomass (i.e., carbon) co-varied with H' (r2 = 0.25), and thus, our dataset showed a positive relationship between forest carbon storage and structural complexity, supporting the concept of multifunctional forestry emphasizing late-successional habitats.

The (Plethodon nettingi) Cheat Mountain Salamander is a rare and endangered species that relies heavily on (Picea rubens) Red Spruce for habitat. P. rubens communities on the Cheat Mountain range in West Virginia have been disturbed by fires and logging, and regeneration of P. rubens stands are central to the survival of the P. netting. A supervised and unsupervised landscape classification of three Landsat images over the past 26 years was conducted to analyze change in P. rubens communities on Cheat Mountain Range. Change detection results revealed that from 1986-2012 a 52% growth increase of P. rubens stands, 18% loss, and 29% stayed the same over the last 26 years. P. rubens stands are vital habitat to the rare and endangered P. netting and regrowth of P. rubens is vital in restoring the habitat of the salamander on the Cheat Mountain. The regrowth of P. rubens on the Cheat Mountain range is critical to the survival of the P. nettingi. Identifying critical forest as it relates to salamander habitat is essential for conservation efforts. Since not all P. rubens stands are of equal significance to the P. nettingi, it is important to identify and map those that adhere to their stringent habitat needs as defined by forest fragmentation, aspect, slope, and lithology. I used spatial analysis and remote sensing techniques to define critical forest characteristics by applying a forest fragmentation model utilizing morphological image analysis, northeast and southwest aspects, moderate slopes, and limestone lithology. Patches were ranked based on this quantitative model and key P. rubens stands identified using spatial statistics. The results could aid in prioritizing research areas as well as conservation planning in regards to P. rubens and the P. nettingi. In this study, the MaxEnt modeling framework was used to predict habitat suitability for P. rubens under current conditions and under two future climate change scenarios. P. rubens distribution data was acquired from the U.S Geological Survey. Both the IPCC A1B and A2 emission scenarios of the HadCM3 global circulation model were projected to years 2040-2069 and 2070-2099. Results showed that a substantial decline in the suitability of future P. rubens habitat on the Cheat Mountain is likely under both climate change scenarios, particularly at lower elevations. By the end of the century, P. rubens is likely to be extirpated from the Cheat Mountain Range. By the end of century, the A1B and A2 scenarios predict the average habitat suitability for P. rubens on Cheat Mountain will be 0.0002 and 0.00004 respectively. Conservation as well as species migration efforts for P. rubens should be focused on areas such as Cheat Mountain to preserve this vital habitat.

O Brasil, um país de dimensões continentais e inúmeros rios em seu território, tem uma enorme carência de pontes para pequenos e médios vãos. Atualmente, a elevada produção de madeira de reflorestamento traz à engenharia uma opção de material renovável e ecologicamente correto para se utilizar em prol do ser humano nas obras de infraestrutura, mais especificamente na construção de pontes, uma vez que a madeira possui ótimo desempenho quando sujeita a cargas de curta duração. A utilização de Madeira Laminada Colada (MLC) permite a fabricação de peças de grandes dimensões, com excelente estabilidade, e com elevado controle de qualidade, proporcionando segurança e confiabilidade à estrutura. Este trabalho tem como objetivo o estudo teórico de pontes em vigas de MLC e tabuleiros em painéis de MLC utilizando procedimentos desenvolvidos por pesquisadores internacionalmente renomados e adequando estes procedimentos para as normas e condições brasileiras. Apresentam-se neste trabalho tabelas para pré-dimensionamento deste tipo de ponte para vãos de 8m a 20m para TB-30 e TB-45. Além disso, analisam-se numérica e experimentalmente os ganhos de rigidez e redução de deslocamentos relativos proporcionados pela utilização de vigas de enrijecimento, bem como a influência da seção destas vigas e a quantidade de parafusos utilizados para interligar ao tabuleiro. Por fim, apresentam-se algumas disposições construtivas não estruturais fundamentais para o bom funcionamento deste tipo de estrutura. / Brazil, a continental size country and with many rivers in its territory, has a huge necessity for short and medium spans bridges. Nowadays, the high production of reforestation wood allows to engineering an option of renewable material and ecologically correct to be used in favor to humans in infrastructure works, most specifically in bridges construction, once timber has a great performance in quick loads. The use of Glued-Laminated Timber (Glulam) enable the manufacture of large sizes members, with excellent stability, and a high control of quality in its production, providing a safety and reliability structure. This work aim the theoretical study of glulam stringers bridge and glulam panels deck using procedures developed by international researchers and adapting those procedures for Brazilian conditions and normalizations. Pre-design tables are presented in this work for 8m to 20m spans for TB-30 and TB-45. In addition to, analyses numerical and experimentally the gain of stiffness and the reduction of relative displacements between panels provided by the use of stiffener beams, besides the influence of those beams section size and number of bolts used for deck interconnection. Finally, it is presented some not structural constructive arrangements essential for good performance of this kind of structure.

Ações de recuperações de áreas degradadas têm sido amplamente empregadas, tanto por exigências legais como por iniciativas de grupos preocupados com a qualidade ambiental, assim não havendo uma padronização destas ações. Surgindo então a necessidade de avaliar se as metodologias empregadas estão alcançando seu objetivo e proporcionando uma auto-sustentação da comunidade florestal formada. O presente trabalho teve como objetivo descrever a comunidade arbustivo-arbórea de uma área restaurada, por meio de um plantio com alta diversidade, após 18 a 20 anos de sua implantação. O estudo foi desenvolvido em uma Floresta Estacional Semidecidual (FES) no município de Iracemápolis estado de São Paulo Sudeste do Brasil (22°35\'S e 47°31\'W). O clima regional é do tipo Cwa segundo a classificação de Köppen, com precipitação variando de 1.100 a 1.700mm por ano. O plantio foi realizado entre 1988 e 1990, em aproximadamente 50ha. Foi realizado um levantamento florístico e fitossociológico de duas áreas com 1,0ha cada, foram amostrados todos os indivíduos com perímetro a altura do peito igual ou maior que 10cm para calculo dos parâmetros fitossociológicos e dos índices de diversidade e de equidade. As espécies amostradas foram classificadas quanto a classe sucessional e a síndrome de dispersão. Foi verificada fisionomia florestal nas duas áreas estudadas. Foram encontrados 2.532 indivíduos vivos, distribuídos em 52,05% na área 1 e 47, 95% na área 2, e estavam distribuídos em 143 espécies, compondo 40 famílias. A altura do dossel foi inferior ao encontrado em remanescentes de FES, porém os índices de diversidade e equidade, bem como a densidade absoluta estiveram entre os valores obtidos para FES. As espécies que apresentaram maior crescimento foram Lafoensia glyptocarpa, Melia azedarach, Pterocarpus violaceus, Centrolobium tomentosum, Cariniana estrellensis, Triplaris americana, Cariniana legalis e Balfourodendron riedelianum na área 1 e Luehea divaricata, Pterogyne nitens, Citharexylum myrianthum e Triplaris americana na área 2. Foram verificados indivíduos com forma de vida vegetais diferentes dos introduzidos assim como espécies arbustivo-arbóreas diferentes das implantadas. A maior parte dos indivíduos regenerantes foi de espécies secundárias iniciais e pioneiras, sendo que as maiores espécies, tanto em altura como em área basal, foram provenientes das espécies plantadas. As duas áreas foram consideradas como restauradas e apresentam características de vegetação secundária. A composição inicial das espécies utilizadas e suas classes sucessionais influenciaram a composição da floresta formada com 18 e 20 anos. A utilização de alta diversidade em plantios de restauração apresenta-se de grande importância para o restabelecimento da estrutura, possibilitando o desenvolvimento dos processos existentes em florestas naturais nas áreas restauradas, especialmente em áreas não conectadas a fragmentos florestais naturais. / Restoration actions in degraded areas have been widely used, as much for legal requirements as for initiatives of groups worried about the ambient quality, in this way not having an standardizing of this actions. Appearing the necessity to evaluate if the employed methodologies are reaching its objective and providing a self-sustentation of the formed forest community. The present work had as objective to describe the community of tree and shrub from restored area, by a high diversity plantation, after 18 and 20 years of your implementation. The study was developed in Semideciduous Seasonal Forests (FES) at Iracemápolis City in São Paulo, Southeastern of Brazil (22°35\'S and 47°31\' W). The regional climate is Cwa, according to Köppen classification, with precipitation varying from 1.100 to 1.700mm per year. The plantation was realized between 1988 and 1990, in approximately 50ha. It was realized a floristic and phytosociological survey from two areas with 1,0ha each, where had been sampled individuals with perimeter at breast height equal or bigger than 10cm for calculate phytosociological parameter and diversity indices of equability. The showed species had been classified according to sucessional class and the syndrome of dispersion. Forest physiognomy was verified in the two studied areas. It has been found 2,532 individuals alive, distributed in 52,05% at area 1 and 47, 95% at area 2, and were distributed in 143 species, composing 40 families. The canopy heights had been less than found in FES remained, however, the diversity and equability index, and the absolute density has been among the value obtained to FES. The species that had presented greater growth had been Lafoensia glyptocarpa, Melia azedarach, Pterocarpus violaceus, Centrolobium tomentosum, Cariniana estrellensis, Triplaris americana, Cariniana legalis and Balfourodendron riedelianum in the area 1 and Luehea divaricata, Pterogyne nitens, Citharexylum myrianthum and Triplaris americana in area 2. Had been verified individuals with different vegetal life forms from introduced species as well as tree and shrub species different from implemented. Most of the regenerate individual was from pioneering and initial secondary species, and the biggest species, in height and in basal area had been coming from the planted species. It is concluded that the two areas are restored and present characteristic of secondary vegetation, the initial composition from used species and respective sucessional class had influenced the forest composition formed with 18 and 20 years. The use of high diversity in plantations of restoration present with high importance to re-establishing of the structure, enabling the development of existing process in a natural forests, especially in areas not connected with fragments of natural forests.

Grande parte das moradias brasileiras apresenta coberturas inadequadas, conforme indicação de pesquisa sobre o deficit habitacional. A carpintaria dessas coberturas necessita de mão de obra qualificada e materiais de custos elevados, porém, na maioria dos casos ainda hoje utiliza processo construtivo artesanal. O objetivo deste trabalho é identificar quais as condições necessárias para viabilizar a produção de sistemas de cobertura adotando o processo de préfabricação com madeiras de florestas plantadas, em contextos com precariedades, como nos casos dos assentamentos rurais. Os estudos se concentraram em dois assentamentos rurais; no primeiro, Assentamento Rural Pirituba II no município de Itapeva - SP, foi desenvolvido o sistema de cobertura VLP (vigas laminadas pregadas) e empregado em 35 moradias; no segundo, Assentamento Rural Sepé Tiaraju localizado no município de Serra Azul - SP, foi desenvolvido o sistema de cobertura Painéis pré-fabricados e empregado em 67 moradias. A estratégia adotada para a coleta de dados do produto e do processo aconteceu ao longo da cadeia de produção dos sistemas de cobertura, começando pelo desenvolvimento do projeto, passando pela realidade social do assentamento até a aplicação das propostas em cada assentamento. O desenvolvimento e escolha da proposta elaborada utilizam o processo participativo com envolvimento direto das famílias em todo o processo. Os resultados obtidos permitem concluir que ambos os sistemas de cobertura pré-fabricados atendem às condições necessárias na redução de custos com materais e mão de obra melhorando a qualidade de acabamento dos sistemas de cobertura mesmo trabalhando em situações com precariedade de infraestrutura. A relevância da pesquisa está no fato de agregar valores não comuns às coberturas das habitações rurais possibilitando a replicação dos princípios adotados em situações semelhantes, mesmo que em contextos diferentes, demonstrando que a pré-fabricação com o processo participativo podem ser alternativas viáveis para comunidades organizadas. / There are many Brazilian houses with inadequate roofs, as indicated by research on the housing deficit. The traditional build-up roofs require skilled labor and expensive materials, made in a handmade construction process. The objective of this research is to identify the necessary conditions to enable the production of roof systems by adopting the pre-fabrication with soft-wood from reforestations, to be applied in precarious situations, such as are found in rural settlements. The studies focused on two rural settlements. At the first, in the Pirituba II (Itapeva SP, Brazil), it was designed the roof system NLB (nailed laminated beams) which covered 35 houses. In another context, the Sepé Tiaraju, located in the municipality of Serra Azul SP (Brazil), it was designed the roof system in prefabricated wood panels, applied in 67 houses. The strategy for collecting data about the product and the process occurred throughout the production chain of roofing systems, starting with the participatory design, through the found social reality, to implementation of proposals in each rural settlement. The development and selection of the proposed solutions counted with the direct involvement of the families throughout the process. With the results it is concluded that both prefabricated roof systems meet the conditions of cost reductions of materials and labor, improving the quality of the finish of the roof system, even when working in situations with precarious infrastructure. The relevance of this research is to add not common value to the roof of rural housing, enabling the replication of the principles in similar situations and demonstrating that the prefabrication and participatory design can be viable alternatives to organized communities.

Em 2012 foi anunciado um pacote econômico do governo que concede à iniciativa privada a operação de estradas e ferrovias pelo Brasil, onde serão investidos R$ 133 bilhões, incluindo a construção de 10 mil quilômetros de estradas de ferro. O dormente é um dos componentes estruturais mais importantes na construção de ferrovias, com a função de receber esforços produzidos pelos veículos ferroviários, amortecer parcialmente as vibrações, transmiti-las ao lastro e manter invariável a distância entre os trilhos (bitola). As madeiras utilizadas no Brasil para a produção de dormentes são de essências nobres. Porém, com a escassez cada vez maior dessas espécies e a exploração ilegal de madeiras nativas consideradas de elevada resistência buscaram-se madeiras alternativas para esse uso como o Eucalipto ou o Pinus de florestas plantadas. Objetivo deste trabalho foi a análise experimental da viabilidade técnica da produção de dormentes pelo método de fabricação da Madeira Laminada Colada utilizando a madeira da espécie de Pinus oocarpa e adesivo poliuretano para atender os requisitos da recém aprovada norma de dormentes ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio. Após intenso programa experimental em que foram estudadas diversas configurações de disposição de lamelas visando à otimização do processo de fabricação, foram produzidos dormentes de MLC com configurações diferentes de seção transversal, e realizados ensaios preliminares com a finalidade de atingir as especificações mínimas de norma. Os resultados mostraram que os dormentes em MLC de Pinus oocarpa atingiram os requisitos da norma ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio. / In 2012 it was announced a government economic package that grants to private operation of roads and railways in Brazil, which will be invested R$ 133 billion, including the construction of 10,000 km railroads. Sleepers are one of the most important structural components in the construction of railways with the function of receiving actions produced by the rail vehicles, diminish dampen vibrations and transmitting them to the ballast and remain invariant distance between rails (gauge). The timbers used in Brazil to manufacture sleepers are from tropical forest. Considering the scarcity and tropical illegal logging, Eucalyptus and Pines planted forests are a interesting alternative. The aim of this study was experimental analyze of the technical feasibility to produce Glulam sleepers using Pinus oocarpa species and polyurethane adhesive to reach the requirements of the recently approved sleepers standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods. After intensive experimental program using various layout settings of lamellae and different configurations of cross-sectional an optimization of the manufacturing process of MLC sleepers was done in order to achieve the minimum standard specifications. Results showed that in MLC sleepers of Pinus oocarpa reached the requirements of the standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-02T12:37:08Z No. of bitstreams: 2 Dissertação - Cassiomar Rodrigues Lopes - 2013.pdf: 4397463 bytes, checksum: 77e10a2616b5b02b9cfa4d9278944278 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-02T15:57:02Z (GMT) No. of bitstreams: 2 Dissertação - Cassiomar Rodrigues Lopes - 2013.pdf: 4397463 bytes, checksum: 77e10a2616b5b02b9cfa4d9278944278 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-02T15:57:02Z (GMT). No. of bitstreams: 2 Dissertação - Cassiomar Rodrigues Lopes - 2013.pdf: 4397463 bytes, checksum: 77e10a2616b5b02b9cfa4d9278944278 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-07-31 / This work presents and discusses the results about the expansion of the cultivation of eucalyptus (Eucalyptus spp) in the Cerrado biome, including the analysis of related variables in this process. The motivation for this research came from the recognition, using data from the Brazilian Institute of Geography and Statistic, of the expansion of this crop, mainly in the state of Mato Grosso do Sul, where it was verified in the last three decades changes in the landscape with the replacement of cattle raising and agriculture. At the same time, there was a regression in eucalyptus plantations in Bahia’s west. It can be argued that this expansion and regression of areas are connected to the presence of forest-based industries in the region that needs this raw material. Therefore, this study sought to identify areas where they are being held eucalyptus plantations in the Cerrado with 2006 census data. These locations were chosen based on these information, and the mapping of the highlighted counties according to the data from the agricultural census. Then it was analyzed the variables physical, political economical and social policies in the producing regions. Based on these features were pointed the prone areas for the expansion of eucalyptus plantation in the Cerrado. In general, the results show that there are a predominance of some characteristics in the choice of areas to be cultivated, as a predominant deep sandly quartzly soils, relief in the class of 0 º to 8 º of declivity and proximity to highways and rivers around 5 km and 3 km, respectively. Another important result of this research, obtained by the intersection of the areas of eucalyptus to the Cerrado and the map of land use (PROBIO), indicates that the expansion of this crop is occurring over areas with remnant Cerrado vegetation. / Neste trabalho são apresentados e discutidos os resultados sobre a expansão do cultivo de eucalipto (Eucalyptus ssp) no bioma Cerrado, incluindo a análise das variáveis relacionadas neste processo. A motivação para esta pesquisa partiu da constatação, através de dados do IBGE, da expansão desta cultura, principalmente no Estado do Mato Grosso do Sul, onde nas últimas três décadas verificou-se mudanças na paisagem com a substituição da pecuária e da agricultura. Ao mesmo tempo, verificou-se uma regressão no plantio de eucalipto na região oeste da Bahia. Pode-se afirmar que esta expansão e regressão das áreas estão ligadas com a presença de indústrias de base florestal na região, que necessitam desta matéria prima. Para tanto, esta pesquisa buscou identificar as áreas onde estão sendo realizados os plantios de eucalipto no Cerrado com dados censitários de 2006. Tais localidades foram escolhidas tendo como base estas informações, sendo realizado o mapeamento dos municípios de destaque segundo os dados do censo agropecuário. Em seguida foram analisadas as variáveis físicas, políticas econômicas e sociais nas regiões produtoras. Com base nestas características foram apontadas as áreas propensas para a expansão do eucalipto no Cerrado. Em geral, os resultados demonstram que existem algumas características em comum nas áreas cultivadas, tais como predomínio de solo arenoquartizoso profundo, relevo com até 0º a 8º de declividade e proximidade de rodovias e rios em torno de 5 km e 3 km, respectivamente. Outro resultado relevante da pesquisa, obtido com a intersecção das áreas de eucalipto para o Cerrado e o mapa de uso da terra (PROBIO), indica que a expansão deste cultivo está ocorrendo sobre áreas de Cerrado remanescente.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-04T18:50:24Z No. of bitstreams: 1 2016 - Fernando Lima Aires Gon?alves.pdf: 4917479 bytes, checksum: d7c7e6d879e9495bcc0db5d59f03c813 (MD5) / Made available in DSpace on 2017-05-04T18:50:24Z (GMT). No. of bitstreams: 1 2016 - Fernando Lima Aires Gon?alves.pdf: 4917479 bytes, checksum: d7c7e6d879e9495bcc0db5d59f03c813 (MD5) Previous issue date: 2016-02-26 / Three studies were conducted to evaluate the efficiency of seedling crowning using cardboard in reforestation with arboreal species of the Atlantic. The first study aimed to test the effect of the crowning with cardboard on the growth of Atlantic Forest species planted in a pasture area with dominance of Andropogon bicornis. The experimental design was randomized blocks with two treatments and 12 repetitions. Treatments consisted of crowning with cardboard or crowning with hoe applied to 11 tree species. We evaluated the growth of plants by measuring the height (H) and diameter of the collar height (DAC) at 6, 12 and 18 months after planting beyond survival rate. It was also carried out an assessment of the costs of each treatment. The results showed that the board did not interfere significantly in any forest species assessed. However, the survival rate was higher in the treatment crown of cardboard (80.7%) compared to the capping treatment with hoe (73.1%). In the economic aspect, the crowning with cardboard obtained material cost and labor up to 50% lower than the crowning with hoe. In the second study we evaluated the crowning efficiency with cardboard in the suppression of four species of grasses commonly found in forest areas in the Atlantic Forest. Four experiments were set up in places with dominant species A. bicornis, Urochloa decumbens, Urochloa umidicola and Panicum maximum. The experimental design was completely randomized with five replications. The treatments were the culmination of cardboard and without crowning. The cardboard efficiency was monitored by sampling the total biomass and the level of senescence of grasses in the area crowned. The cardboard was efficient in suppressing the four species of grasses evaluated, because after the evaluation period (100- 170 days) had hardly live plant material in the field of crowns. In the third study was rated as the crowning with cardboard influences the temperature and moisture in the surface layers in the soil. The experimental design was a randomized complete block design with four treatments and eight repetitions. The treatments were 1 - crown with cardboard (cardboard disposed directly on the braqui?ria); 2 - no crowning; 3 - with cardboard crown after crown with hoe (willing cardboard on the exposed soil); 4 - crowning with hoe. The moisture in the layers from 0 to 5 cm and 5 to 10 cm of soil, and the temperature in the layers 0 and 2,5 cm, 2.5 to 5 cm and 5 to 10 cm of the soil were monitored during periods 19 and subsequent 7 days, respectively, at a rain simulation 130 mm for 24 hours and natural rainfall of 133 mm for 13 days. The results indicated that treatment 1 (crowning with cardboard) decreased soil drying speed while maintaining higher water content in the crown area compared to the other treatments. Both capping treatments showed cardboard soil temperature in the region of the crown to 8.5?C lower than the capping treatment with cardboard. The set of results of the three studies demonstrate that the use of the capping technique with cardboard in reforestation deployment can significantly reduce operating costs after planting, either by reducing hand labor used in capping operations, as the lower need for seedlings for replanting. / Foram conduzidos tr?s estudos objetivando avaliar a efici?ncia do coroamento de mudas com papel?o em reflorestamentos com esp?cies arb?reas da Mata Atl?ntica. O primeiro estudo teve como objetivo testar o efeito do coroamento com papel?o sobre o crescimento de esp?cies da Mata Atl?ntica plantadas em uma ?rea de pastagem com domin?ncia de Andropogon bicornis. O delineamento experimental foi em blocos casualizados com dois tratamentos e 12 repeti??es. Os tratamentos consistiram de coroamento com papel?o ou coroamento com enxada aplicados a 11 esp?cies arb?reas. Avaliou-se o crescimento das plantas atrav?s da mensura??o da altura (H) e di?metro a altura do coleto (DAC) aos 6, 12 e 18 meses ap?s o plantio al?m da taxa de sobreviv?ncia. Tamb?m foi realizada uma avalia??o dos custos de cada tratamento. Os resultados encontrados mostraram que o papel?o n?o interferiu de maneira significativa em nenhuma esp?cie florestal avaliada. Entretanto, a taxa de sobreviv?ncia foi maior no tratamento de coroamento com papel?o (80,7%) comparado ao tratamento de coroamento com enxada (73,1%). No aspecto econ?mico, o coroamento com papel?o obteve custo de material e m?o de obra at? 50% inferior ao do coroamento com enxada. No segundo estudo avaliou-se a efici?ncia do coroamento com papel?o na supress?o de quatro esp?cies de gram?neas forrageiras comumente encontradas em ?reas de reflorestamento no bioma Mata Atl?ntica. Foram montados quatro experimentos em s?tios com domin?ncia das esp?cies A. bicornis, Urochloa decumbens, Urochloa umidicola e Panicum maximum. O delineamento experimental foi o inteiramente casualizado com cinco repeti??es. Os tratamentos foram o coroamento com papel?o e sem coroamento. A efici?ncia do papel?o foi monitorada atrav?s de coletas da biomassa total e do n?vel de senesc?ncia das gram?neas na ?rea coroada. O papel?o se mostrou eficiente na supress?o das quatro esp?cies de gram?neas avaliadas, pois ap?s o per?odo de avalia??o (100 a 170 dias) praticamente n?o havia material vegetal vivo na ?rea das coroas. No terceiro estudo foi avaliado como o coroamento com papel?o influencia na temperatura e umidade nas camadas superficiais no solo. O delineamento experimental foi o de blocos casualizados com quatro tratamentos e oito repeti??es. Os tratamentos foram 1 ? coroamento com papel?o (papel?o disposto diretamente sobre a braqui?ria); 2 ? sem coroamento; 3 ? coroamento com papel?o ap?s coroamento com enxada (papel?o disposto sobre o solo exposto); 4 ? coroamento com enxada. A umidade, nas camadas de 0 a 5 cm e 5 a 10 cm do solo, e a temperatura, nas camadas de 0 a 2,5 cm, 2,5 a 5 cm e 5 a 10 cm do solo, foram monitorados durante per?odos de 19 e 7 dias subsequentes, respectivamente, a uma simula??o de chuva de 130 mm durante 24 hs e a chuvas naturais de 133 mm durante 13 dias. Os resultados indicaram que o tratamento 1 (coroamento com papel?o) diminuiu a velocidade de ressecamento do solo, mantendo maior teor de ?gua na ?rea da coroa em compara??o aos demais tratamentos. Ambos os tratamentos de coroamento com papel?o apresentaram temperatura do solo na regi?o da coroa at? 8,5?C menor do que no tratamento de coroamento com papel?o. O conjunto de resultados dos tr?s estudos realizados demonstram que o uso da t?cnica de coroamento com papel?o na implanta??o de reflorestamentos pode reduzir significativamente os custos operacionais ap?s o plantio, tanto pela redu??o de m?o-de-obra empregada em opera??es de coroamento, quanto pela menor necessidade de replantio de mudas.

Refazer ecossistemas de forma artificial representa um desafio de iniciar um processo de sucessão o mais semelhante possível aos processos naturais. A recuperação ambiental tem se baseado no modelo da silvicultura tradicional, plantandose árvores sob espaçamento 3 x 2 m, em área total, com altos insumos de implantação/manutenção, e gerando-se bosques desenvolvidos em altura, porém com baixa diversidade de formas de vida e regeneração. Técnicas nucleadoras de restauração formam microhabitats em núcleos propícios para a chegada de uma série de espécies de todas as formas de vida, que num processo de aceleração sucessional, irradiam diversidade por toda a área. As técnicas foram implantadas em áreas piloto de um hectare, denominadas "Unidades Demonstrativas" (UDs). As UDs foram montadas em Floresta Estacional Semidecidual (Capão Bonito-SP), Cerrado (Santa Rita do Passa Quatro-SP) e Restinga (Florianópolis-SC). Na primeira UD, com um ano de idade, as técnicas nucleadoras introduziram 1.603 mudas de 148 espécies nativas, dentre 84 espécies arbóreas (883 mudas), 12 arbustivas (124 mudas), 30 herbáceas (242 mudas), 20 trepadeiras (260 mudas) e 2 bromeliáceas (3 mudas), além de 94 mudas de hábito indeterminado. Entre as espécies, ocorreram 69 zoocóricas, 32 autocóricas e 29 anemocóricas, além de 21 plantas indeterminadas. Desconsiderando-se as 47 espécies arbóreas implantadas por mudas, houve introdução de: 25% de arbóreas, 8% de arbustos, 20% de ervas, 14% de lianas e 1% de bromeliáceas. Na UD de Cerrado, apesar de impactada por gado, aos dois anos de idade, foram introduzidos 354 indivíduos de 31 espécies nativas. Destas, 39% foram espécies arbóreas, 13% arbustivas, 16% herbáceas, 16% lianas e 16% indeterminadas. Foram registradas 35% de espécies zoocóricas, 29% de anemocóricas, 19% de autocóricas e 16% de plantas com síndrome indeterminada. Na UD de Restinga, foram detectadas, aos dois anos e meio de idade, 180 espécies de 108 gêneros e 55 famílias. As técnicas nucleadoras resultaram num custo experimental estimado em torno de 34% mais barato em relação ao modelo tradicional que varia em torno de R$ 5.500,00 reais/ha. O uso da nucleação aumentou nitidamente a eficiência da restauração ecológica. Foi restituída a diversidade, não só em seu aspecto estrutural, mas considerando-se também os diferentes nichos, formas e funções, formando um mosaico de ambientes e permitindo uma maior dinâmica das comunidades. No atual estágio de conhecimento, é importante a definição de qual paradigma almejamos para a restauração de nossas florestas: cultivar plantações de árvores nativas ou permitir e acelerar a sucessão natural? O novo paradigma das técnicas nucleadoras, ao contrário dos modelos tradicionais de recuperação que apenas satisfazem exigências legais, promovem a restituição de produtores, consumidores e decompositores, gerando a conservação efetiva dos ecossistemas, e assumindo, desta forma, um compromisso ético com as futuras gerações. / To remake ecosystems of artificial form represents a challenge to initiate a process of the possible most similar succession to the natural processes. The environmental recuperation has based on the model of traditional forestry, standing trees under 3 x 2 m spacing, in total area, with high implantation/ maintenance inputs, and generating forests developed in height, however with low diversity of forms of life and regeneration. Restoration nucleation techniques form microhabitats in nuclei propitious for the arrival of a series of species of all the life forms that in a process of sucessional acceleration, radiate diversity for all the area. The techniques had been implanted in pilot areas of one hectare, called "Demonstrative Units" (UDs). The UDs had been mounted in seasonal semidecidual forest (Capão Bonito-SP), Brazilian savanna (Santa Rita do Passa Quatro-SP) and coastal plain vegetation (Florianópolis-SC). In the first UD, with one year of age, the nucleation techniques had introduced 1,603 seedlings of 148 native species, amongst 84 arboreal species (883 seedlings), 12 shrubs (124 seedlings), 30 herbaceous ones (242 seedlings), 20 lianas (260 seedlings) and 2 bromelias (3 seedlings), in addition to 94 seedlings of indeterminate habit. Among the species, 69 zoochore, 32 autochore and 29 anemochore had occurred, plus 21 indetermined plants. Disrespecting the 47 arboreal species implanted by traditional seedlings, there was introduction of: 25% of arboreal, 8% of shrubs, 20% of herbaceous, 14% of lianas and 1% of bromelias. In Brazilian savanna UD, although affected by cattle when two years of age, 354 individuals of 31 native species had been introduced. Of these, 39% had been arboreal species, 13% shrubs, 16% herbaceous, 16% lianas and 16% indetermined. There had been registered 35% of zoochore species, 29% of anemochore, 19% of autochore and 16% of plants with indetermined syndrome. In coastal plain vegetation UD, in two years and half of age, 180 species of 108 genus and 55 families had been detected. The nucleating techniques had resulted cheaper in an esteemed experimental cost around 34% in relation to the traditional model that varies around R$ 5,500.00 reais/ha. The use of the nucleation clearly increased the efficiency of the ecological restoration. The diversity not only restituted its structural aspect, but also the different niches, forms and functions, forming an environment mosaic and allowing a dynamic growth of the communities. In the current period of knowledge, is important the definition of which paradigm we wish for the restoration of our forests: to cultivate plantations of native trees or to allow and to speed up the natural succession? The new paradigm of the nucleation techniques, in contrast to the traditional models of recovery that only satisfy legal requirements, replenishes the producers, consumers and decompositors, promoting the conservation of the ecosystems, and adopting an ethical commitment with the future generations.

La Grande muraille verte est le nom d’un programme régional de lutte contre la désertification au Sahel lancé en 2007 sous l’égide de l’Union africaine et des organisations régionales. Il consiste à favoriser le reboisement des territoires semi-arides le long d’un tracé reliant Dakar à Djibouti et traversant onze États, afin de créer un « bandeau végétal dressé face à l’avancée du désert ». Cette thèse a pour but de proposer une lecture géographique et critique de ce projet insolite, appréhendé ici comme une utopie environnementale. À partir d’enquêtes de terrain principalement menées au Sénégal (région du Ferlo) et enrichies par les apports de la political ecology, elle met en lumière la tension qui existe entre d’un côté, la formulation d’un projet de territoire au nom du développement des zones semi-arides et de la gestion des ressources naturelles et, de l’autre, la promotion d’un instrument d’extraversion politique et économique permettant de capter de nouvelles rentes environnementales : en quoi la territorialisation du projet est-elle subordonnée à une quête de visibilité globale ? La première partie montre comment la Grande muraille verte recycle dans un moment historique favorable des pratiques anciennes en matièr ede lutte contre la désertification. La deuxième partie décrit le déficit d’ancrage territorial de ses aménagements à l’échelle locale. La troisième partie montre que l’appropriation globale du projet est la source principale de sa grande résilience. / The Great Green Wall is a regional initiative to combat desertification in the Sahel. It was launched in2007 under the leadership of the African Union and other regional organisations. The program supports reforestation of drylands from Dakar to Djibouti, and aims to form a line of trees protecting against desert encroachment. In a geographical and critical perspective, it can regarded as a green utopia. This thesis, based essentially on field research carried out in Senegal (Ferlo region) supplemented by political ecology insights sheds light on the existing tension between two approaches to the project : one, the objectives of this local project are to develop drylands and better manage natural resources, and two, it can also be seen as promoting an instrument of political and economic extraversion, producing newrent-seeking opportunities. To what extent can the territorialization process of the local project be impaired by the search for global visibility ? The first part shows how the Great Green Wall, at a historical moment, is reactivating traditional techniques to combat desertification. The second partdescribes the lack of territorial anchorage and its local applications. The third part shows that the project derives its great resilience mainly from global ownership.