Dans les systèmes agroforestiers simples à deux strates, la distribution de la lumière sous les couronnes des arbres est un facteur clé pour le développement de la culture associée. Cette distribution évolue en fonction des saisons et de la dynamique de croissance de la strate arborée. La lumière disponible pour la culture dépend de la quantité de lumière interceptée par les couronnes des arbres et par conséquent de l'architecture des espèces utilisées. L'objectif de cette thèse est de déterminer le rôle de l'architecture de deux espèces, Acacia mangium Willd. et Tectona grandis L., dans (i) les modalités de l'interception de la lumière par les couronnes et par les feuilles et (ii) les variations intra- et interspécifiques de la distribution du rayonnement sous les couronnes de ces arbres selon leur âge. A partir de l'analyse dynamique des processus de croissance et de ramification de ces deux espèces, un échantillonnage des organes foliaires a permis de déterminer leur répartition, leur géométrie et leurs caractéristiques morphologique, anatomique, optique et biochimique dans les couronnes. Par la simulation de la croissance, de ces deux espèces, paramétrée via des lois mathématiques de croissance et de ramification, des reconstructions 3D d'arbres ont été réalisées en vue de simuler le bilan radiatif de sous-parcelles agroforestières. Les résultats montrent de fortes variations inter- et intraspécifiques de la distribution des organes foliaires et leurs caractéristiques au sein de la couronne et de la distribution du rayonnement sous les couronnes. Les stratégies adoptées par ces deux espèces pour optimiser l'interception lumineuse sont discutées

Clones of the Eucalyptus grandis x Eucayptus nitens (GN) hybrids were produced and selected through the CSIR‟s breeding programmes for colder plantation sites in South Africa. Some GN clones consistently exhibit high and superior pulp properties, which makes them valuable for commercial plantations in South Africa. In nurseries, stockplants are usually seven cm in length and maintained at high (100 x1.5 m-2) planting density. However, rooting frequency varies with season and little is known about the impact of position of cuttings on overall rooting frequency of a clone. The aim of this study was to investigate the effect of size and planting density of stockplants in mini-hedges, on the yield and subsequent rooting of cuttings from various positions of GN clones of known rooting potential (i.e. GN 018B: difficult-to-root and PP 2107: easy-to-root clones). Stockplants (10 cm vs. 20 cm) were established at high (100 x 1.5 m-2) and at low (25 x 1.5 m-2) densities for GN 018B and PP 2107 under commercial nursery conditions in a polyethylene tunnel. Cuttings were harvested every two to three weeks in September-October 2010 (spring), December 2010-January 2011 (summer), April-May 2011 (autumn) and June-July 2011 (winter). The harvested material was 5 – 7 cm in length and the light intensity received by individual stockplants at the two planting density levels was recorded. Harvested cuttings from the three positions (apical, middle and basal shoots) were used for: (i) rooting experiments under nursery conditions, (ii) bio-stimulant analysis using the mung bean bioassay, and (iii) analysis of soluble sugars. Between spring and summer 2010, the two GN clones established at low density yielded a similar number of cuttings, but differences in the rooting frequencies were significant in favour of PP 2107 clone. Similar observations were made at high density in terms of production of cuttings, but the significant differences in the rooting observations were reversed between the clones. The GN 018B clone had low rooting rates in summer under nursery conditions but its tissue extracts promoted higher rooting in the bioassay during that time, when compared to spring. Spring and summer had similar effects on rooting responses of PP 2107 cuttings in nursery and bioassay experiments. For both clones, short stockplants produced fewer cuttings but had a higher rooting frequency than cuttings from tall stockplants, with a high rooting frequency recorded from basal cuttings. Similar results were observed in the bioassay experiments which showed high rooting potential of mung bean hypocotyls cuttings using tissue extracts of PP 2107 cuttings maintained at high planting density. Although apical cutting tissues had high concentration of sugars (i.e. sucrose, glucose and fructose), their rooting rates were usually lower at high and low planting density compared to middle and basal cuttings. Sucrose concentration was the highest sugar present in stockplants grown under low planting density. A higher and lower rooting frequency was also observed in autumn although the two clones responded differently to Quambalaria eucalypti (Sporothrix eucalypti) disease infestations. Position, size and genotype had a significant impact on type and concentration of sugar (i.e. sucrose, glucose and fructose), particularly in PP 2107 clone, although rooting rates in the bioassay did not correlate with sugar contents of Eucalyptus cuttings. High carbohydrate (i.e. soluble sugar) content and auxin concentration increased production and subsequent rooting of cuttings across both clones, particularly in spring. Furthermore, rooting was enhanced by relatively higher light intensity intercepted by individual stockplants and in particular the GN 018B clone. Light intensity in the high and low planting densities caused variation in the rooting frequencies thereby increasing or decreasing soluble sugar and auxin concentrations of the two clones. Light intensity and fertiliser concentration received by tall and short stockplants impacted on endogenous hormone levels thereby increasing or decreasing rooting. High sugar concentration levels of PP 2107 clone increased its susceptibility to fungal infection thereby decreasing its rooting frequency in autumn, as its rooting rates increased in winter. Overall results of the investigation revealed that PP 2107 clone has higher rooting potential than GN 018B clone, in particular at high planting density and if stockplants are not infected by fungal diseases. Higher sugar levels were recorded in spring for PP 2107, although rooting rates of mung bean hypocotyl cuttings were higher in summer for GN 018B, suggesting that sugars have nothing to do with rooting of GN cuttings. Season, planting density and size of stockplants affect the rooting frequency of GN clone. Thus, short stockplants maintained at low and high planting densities are recommended for GN 018B and PP 2107 respectively, although the impacts of fertilisers and pathogen resistance on rooting rates still need to be investigated under similar conditions. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2005. / The aim of this study was to develop a set of models that will allow the determination of volume for Tectona grandis trees and stands grown in plantation form in Tanzania. As a secondary objective, models describing tree and dominant stand height were developed. Total volume and volume ratio models were fitted that respectively predict total tree volume and merchantable volume. In order to allow the calculation of volume for different product classes and dimensions, taper models were fitted. All the data were collected by non-destructive sampling methods using a Barr and Stroud optical dendrometer. This proved to be an accurate and inexpensive method of collecting data for developing volume and taper models. Sampling stratification was based on age and site quality and as wide a range as possible was covered to ensure adequate representation of all growing sites and ages present in Tanzanian teak plantations. A total of 2617 individual observations were made from 222 trees at three teak plantations. Several models were selected from the literature to describe teak volume and shape. Results indicated that the Schumacher and Hall (1933) volume equation best describes total volume over and underbark to a fixed upper limit of 7.5 cm. Merchantable volume to upper stem diameter and height limits were best described by respectively the Burkhart (1977) volume ratio model and the Cao and Burkhart (1980) modification thereof. Many of the fitted taper models were unable to adequately describe stem shape over the whole stem, mainly due to the large range in tree sizes and ages used in model fitting. The variable form taper model by Perez, Burkhart and Stiff (1990) provided the best results according to various criteria and is recommended for predicting teak underbark diameters to various heights and, if only a single model is required, the merchantable volume. Top height growth of teak stands was adequately described by the generalized Schumacher (1939) model with the value of the exponent k estimated from the sample data. From this a series of anamorphic site index curves were developed. Suitable height-dbh curves were obtained by a simple linear model and predictions improved by including stand age and site index as predictor variables.

Thesis (MScFor)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: South Africa is a timber scarce country that will most probably experience a shortage of structural timber in the near future. In this study the concept of using young finger‐jointed Eucalyptus grandis timber was evaluated for possible application in roof truss structures while the timber is still in the green, unseasoned state. 220 finger‐jointed boards of cross‐sectional dimension 48 x 73 mm and 36 x 111 mm timber, cut from 5‐18 year old Eucalyptus grandis trees were obtained from Limpopo province, South Africa. The boards were manufactured using a polyurethane (PU) adhesive at moisture content levels above fibre saturation point and no drying was performed. The objectives of this study were to determine various mechanical and physical properties of this finger‐jointed product. More specifically (1) to determine the strength and stiffness potential of the product in the wet and the dry condition, (2) to evaluate physical properties such as density, warp, checking and splitting, (3) to evaluate potential indicator properties to be used as structural grading parameters, and (4) to compare the flexural properties to the current SA pine resource and SANS structural grade requirements. The boards were divided into two groups of the same size, which constituted the wet and the dry samples. Each sample was further separated into six different groups for testing the different strength and stiffness properties. The dry group was stacked in a green‐house for nine weeks until equilibrium moisture content was reached. Afterwards selected physical properties such as warp, checking and splitting were assessed. Destructive testing was conducted on the boards and the results were used to determine various mechanical properties. Finally, each board was assessed for density and moisture content (MC) values. The study showed that the young finger‐jointed Eucalyptus grandis timber had very good flexural properties. Both mean modulus of elasticity (MOE) and modulus of rupture (MOR) 5th percentile strength values for wet and dry boards complied with the current SANS 10163‐1 (2003) requirements for grade S7.The values of tensile perpendicular to grain and compression perpendicular to grain strength did not conform to SANS requirements for grade S5. The other strength properties for the wet and dry groups complied with one of the three SANS structural grades. The 5 year old (48 x 73 mm) boards’ showed significantly higher levels of twist and checking compared to 11 year old boards of the same dimension. Only 46.3% of the finger‐jointed products conformed to the density requirements in SANS 1783‐2 (2004) for grade S7. There was a significant difference in density between the three age groups (5, 11 and 18 years) presented in this study. The variation in both MOE and MOR values of the fingerjointed product proved to be significantly lower in comparison to currently used SA pine sources. Based on the results from this study the concept of producing roof trusses from wet, unseasoned and finger‐jointed young Eucalyptus grandis timber has potential. However, additional research on a number of issues not covered in this study is still required for this product including full scale truss evaluations, proof grading, PU adhesive evaluation at elevated temperatures, nail plate load capacity, and the possible need for chemical treatment of the product against Lyctus beetles. / AFRIKAANSE OPSOMMING: Suid Afrika is ‘n land wat waarskynlik ‘n tekort aan strukturele hout sal ervaar in die nabye toekoms. In hierdie studie word die gebruik van jong gevingerlasde Eucalyptus grandis hout vir die moontlike gebruik in dakstrukture, terwyl nat en ongedroog, ondersoek. 220 gevingerlasde planke van deursnit 48 x 73 mm en 36 x 111 mm gesaag van 5‐18 jaar‐oue Eucalyptus grandis bome en afkomstig van die Limpopo provinsie in Suid Afrika, is gebruik. Die produk is vervaardig met poli‐uretaan (PU) lym uit planke met vog inhouds vlakke bo veselversadigingspunt. Die doelwit van hierdie studie was om verskeie meganiese en fisiese eienskappe van die vingerlas produk vas te stel. Meer spesifiek (1) om die sterkte en modulus van elastisiteit (MOE) potensiaal van die vingerlas produk in die nat en droë toestand te analiseer, (2) om die fisiese eienskappe soos digtheid, vervorming, oppervlakbarse en spleting te ondersoek, (3) om potensiële graderingsparameters te evalueer, en (4) om die buigeienskappe van die produk te vergelyk met SA dennehout asook die SANS strukturele graad vereistes. Die planke is verdeel in twee groepe, ‘n nat groep en ‘n droë groep. Elke groep is verder verdeel in ses kleiner groepe soos buig, trek en drukmonsters. Die droë groep was in ‘n kweekhuis geplaas vir nege weke totdat veselversadigingspunt bereik is. Daarna is geselekteerde fisiese eienskappe soos vervorming, oppervlak barse en spleting gemeet. Destruktiewe toetsing is uitgevoer op die planke en die resultate was gebruik om verskeie meganiese eienskappe vas te stel. Laastens is elke plank se digtheid en voggehalte gemeet. Die studie het getoon dat die jong gevingerlasde Eucalyptus grandis hout goeie buigeienskappe het. Beide die gemiddelde MOE en buig sterkte 5de persentiel waardes van die nat en droë groep het voldoen aan die huidige SANS 10163‐1 (2003) vereistes vir graad S7. Die sterkte‐eienskappe van loodregte trekkrag en loodregte druk het nie die vereistes vir SANS graad S5 gemaak nie. Die ander sterkte‐eienskappe van die nat en droë groep het voldoen aan een van die drie SANS strukturele graadvereistes. Die 5 jaar‐oue (48 x 73 mm ) planke het beduidend hoër vlakke van draai‐trek en oppervlakbarste getoon as die 11 jaar‐oue planke van dieselfe dimensie. Slegs 46.3% van die vingerlas produk het voldoen aan digtheidsvereistes vir SANS graad S7. Daar was ‘n beduidende verskil in dightheid tussen die drie ouderdomsgroepe (5, 11 en 18 jaar). Die MOE en buigsterkte‐waardes van die Biligom produk het beduidend laer variasie as huidige SA denne houtbronne getoon. Die resultate verkry in die studie toon dat die konsep om dakkappe te vervaardig van nat, gevingerlasde jong Eucalyptus grandis hout die potensiaal het om suksesvol toegepas te word. Bykomende navorsing oor ‘n aantal faktore wat nie in hierdie studie ingesluit is nie word steeds benodig. Dit sluit in ‘n volskaalse dakkap evaluasie, proefgradering, PU lym evaluasie by hoë temperature, spykerplaat ladingskapasiteit en die moontlike noodsaaklikheid van chemiese behandeling van die produk teen Lyctus kewers, insluit.

Orientador: Antonio Carlos Nogueira / Dissertação (mestrado) - Universidade Federal do Parana, Setor de Ciencias Agrarias / Área de concentração: Silvicultura / O presente trabalho teve por objetivos avaliar os efeitos dos diferentes tratamentos de manejo hídrico, habitualmente utilizado durante a rustificação, na qualidade de mudas de Eucalyptus grandis Hill ex. Maiden, utilizando parâmetros morfológicos, fisiológicos e nutricionais. O ensaio envolveu também os efeitos da rustificação na sobrevivência das mudas no campo. O estresse hídrico sofrido pelas mudas foi determinado com base na tensão de retenção de água pelo substrato. Os tratamentos foram : mudas sem sofrer déficit hídrico durante a rustificação (permanentemente subirrigadas); mudas irrigadas ao atingir uma tensão de retenção de água pelo substrato de -0,05 MPa; mudas irrigadas ao atingir uma tensão de retenção de água pelo substrato de -0,1 MPa; mudas irrigadas ao atingir uma tensão de retenção de água pelo substrato de -0,5 MPa e mudas irrigadas ao atingir uma tensão de retenção de água pelo substrato de -1,5 MPa. As características morfológicas determinadas foram: altura da parte aérea, diâmetro do colo, pesos de matéria verde e de matéria seca da parte aérea, pesos de matéria verde e de matéria seca da parte radicial, pesos de matéria verde e de matéria seca total, área foliar e peso específico foliar. As características fisiológicas determinadas foram clorofila, potencial hídrico no ponto correspondente ao estresse e transpiração. Os resultados obtidos indicam que o regime hídrico afetou muito a qualidade da muda. Todas as características morfológicas tiveram seus valores reduzidos proporcionalmente ao aumento do estresse hídrico aplicado. Quanto às características fisiológicas, pôde-se constatar que o teor de clorofila não foi afetado pelo manejo hídrico, entretanto a transpiração foi fortemente relacionada ao estresse hídrico. Quanto maior o estresse menor foi a transpiração e maior foi a sobrevivência das mudas no campo, mostrando ser esta característica muito importante na determinação da qualidade da muda. Com relação à caracterização nutricional, observou-se que a movimentação dos nutrientes do substrato ao longo do tubete foi diferente para cada manejo hídrico. Geralmente houve acúmulo dos minerais no substrato da parte superior do tubete, e em geral, quanto maior o estresse maior foi a diferença entre os teores de nutrientes do substrato da parte inferior em comparação com aquele da parte superior do tubete. Na planta, praticamente não ocorreram alterações nas concentrações dos nutrientes. A variação que ocorreu na quantidade total de nutrientes na planta nos diferentes tratamentos esteve relacionada ao peso da matéria seca. / This study characterized Eucalyptus grandis Hill ex. Maiden seedlings in terms of morphological, physiological and nutritional parameters under different degrees of water stress during enharding, and related them to seedling survival in out planting. It was carried out along 1996 at Faculdade de Ciências Agronômicas of Unesp, in the municipality of Botucatu, State of Säo Paulo. The water stress suffered by the seedlings was determined based on water retention tension by the growing medium. The treatments applied were: a) water-stress-free seedlings (permanently sub-irrigated); b) seedlings irrigated when reaching: -0,05 MPa; c) - 0,1 MPa; d) -0,5 MPa and e) -1,5 MPa. The morphological seedling characteristics measured were: shoot height, collar diameter, shoot and root turgid and dry weight and total turgid and dry weight, leaf area and specific leaf weight. The physiological characteristics determined were: chlorophyll, leaf water potential at stress tention on each treatment, and transpiration. The results pointed out that the water management strongly influenced the seedling quality. All the morphological characteristics had decreasing values when on high water stress. The amount of chlorophyll did not change at water management but transpiration was strongly related to water stress. The higher the stress the lower the transpiration, increasing seedling survival in the out planting, indicating that this parameter is important in determining seedling quality. Nutrients movement in growing medium along the container differed in each treatment. In general, mineral nutrients were accumulated in growing medium at the upper part of the container. The higher the stress, the greater the difference between nutrients content in the growing medium at container upper and lower parts. Changes in nutrient concentration in the plant were not observed. Variation of total nutrients in the plant at different tratments was related to dry weight.

Submitted by IZABEL CHRISTINA GAVA DE SOUZA null (izabelsouza@suzano.com.br) on 2016-09-30T11:03:11Z No. of bitstreams: 1 Tese_Izabel_2016_1.pdf: 1921899 bytes, checksum: cce906c3ffd78242151254d344282fb0 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-09-30T13:09:58Z (GMT) No. of bitstreams: 1 souza_icg_dr_bot.pdf: 1921899 bytes, checksum: cce906c3ffd78242151254d344282fb0 (MD5) / Made available in DSpace on 2016-09-30T13:09:59Z (GMT). No. of bitstreams: 1 souza_icg_dr_bot.pdf: 1921899 bytes, checksum: cce906c3ffd78242151254d344282fb0 (MD5) Previous issue date: 2016-07-29 / Este trabalho teve como objetivo propor um novo método de melhoramento para Eucalyptus visando obter materiais genéticos para plantio operacional, por meio dos seguintes estudos: a) avaliar o ganho em produtividade volumétrica de madeira na seleção aplicada numa população clonal de Eucalyptus grandis oriunda da mistura de clones selecionados em progênies de polinização controlada (irmãos completos); b) avaliar a variabilidade genética a partir de marcadores moleculares microssatélites na população clonal selecionada, quando submetida a diferentes condições ambientais e níveis de seleção. Com as sementes obtidas no cruzamento controlado foi instalado um plantio experimental na Fazenda Ribeirão Grande (município de Salesópolis/SP) de propriedade da Suzano Papel e Celulose no ano de 2001. Aos 6 anos de idade foi realizada a seleção de árvores superiores (clones) com base nos caracteres silviculturais e densidade básica da madeira. Foram selecionados 57 clones (irmãos completos), os quais foram propagados vegetativamente, misturados para a formação do minijardim clonal e posterior produção de mudas para plantio operacional na empresa. Este material genético foi recomendado para plantio em 2010. Para este trabalho foram selecionadas três áreas de plantio operacional desse material genético, denominado aqui população clonal inicial com idade de 3,3 a 3,5 anos. Em cada local foram estabelecidas 3 parcelas de 100 árvores e realizada a avaliação silvicultural das árvores. Com os dados de DAP foi feita a ordenação dos valores (maior para o menor) e selecionadas as 40 árvores com maiores valores de DAP e boa forma do tronco, e as 15 árvores com menores valores de DAP totalizando 405 árvores. O perfil genético por meio de marcadores moleculares microssatélites foi realizado para as árvores selecionadas, clones que formam a população clonal inicial e clones genitores. O Incremento Médio Anual com casca aos 7 anos de idade (IMA7; m3/ha/ano) foi estimado por parcela e níveis de seleção de 10%, 20%, 30% e 40%. Com o perfil genético das 40 árvores selecionadas por parcela obteve-se os clones presentes na seleção, como também, os clones presentes nas 15 árvores de comportamento silvicultural inferior. Os resultados mostram que o método de seleção e melhoramento em populações clonais de E. grandis é promissor, diminuindo o tempo de obtenção de materiais genéticos para plantio operacional. Os níveis de seleção de 30% e 40% são os mais indicados para conservar um bom número de clones e obter ganhos em produtividade em curto prazo. / The objective of this work was to propose a new method for breeding to Eucalyptus in order to obtain genetic material for commercial planting by the following studies: a) evaluate the gain, in wood volumetric productivity, in the selection applied to a clonal population of Eucalyptus grandis coming from a selected clonal mixture obtained in cross-pollinated progenies (full sibling); b) evaluate the genetic variability using microsatellite markers obtained in a selected clonal population when subjected to different environmental conditions and levels of selection. Using the seeds obtained in the hand pollination, an experimental plantation was established, in 2001, at the Ribeirão Grande Farm in the municipality of Salesópolis, State of São Paulo, Brazil, owned by Suzano Pulp and Paper. At the age of 6 years old, a selection of superior trees (clones) was carried out based on silvicultural traits and wood density. Fifty-seven clones (full-siblings) were selected, propagated using vegetative technique and used for mixed plantation in a clonal garden to subsequent production of seedlings for commercial planting. This genetic material (initial clonal population) was recommended for planting in 2010. For this study, three commercial areas planted with these genetic materials at ages ranging from 3.3 to 3.5 years old were selected. On each site, 3 plots of 100 trees were established and the silvicultural evaluation of trees was made. The trees were ordered using the diameter at breast height (DBH) data (highest to lowest) and the 40 trees with the highest DBH values and good shape of the trunk were selected, and the 15 trees with lower DBH values, totaling 360 trees. The genetic profile through microsatellite markers was conducted for selected trees, for clones that form the initial clonal population and for parental clones. The Annual Average Increase in shell to the 7 years old (IMA7; m3 / ha.year) was estimated per plot and 10, 20, 30 and 40% selection of levels. Throughout the genetic profile of the 40 selected trees per plot, the presented clones in the selection were obtained, but also, the clones present in 15 trees with lower silvicultural behavior. The results show that the method selection and improvement in clonal populations of E. grandis is promising, decreasing the time for obtaining genetic materials for commercial plantation. Check levels of 30 and 40% are the most suitable to preserve a good number of clones and to obtain short-term productivity gains.

Made available in DSpace on 2014-06-12T15:04:58Z (GMT). No. of bitstreams: 2 arquivo1766_1.pdf: 916614 bytes, checksum: d16125fdbdb2b99a4f6d33952c69a16b (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / O bicudo do algodoeiro, Anthonomus grandis Boheman, é considerado a maior praga da cotonicultura mundial, ocasionando danos que repercutem principalmente na produtividade, qualidade do algodão colhido e gasto com medidas de controle. Neste estudo foi realizada pela primeira vez, uma análise da diversidade e estrutura genética das populações naturais de A. grandis do Brasil. Doze populações coletadas em seis estados brasileiros (Paraíba, Ceará, Bahia, Pará, Mato Grosso e Goiás) em áreas onde são praticadas a agricultura em escala empresarial e agricultura familiar, foram avaliadas pelas técnicas de Polimorfismo do DNA Amplificado Randomicamente (RAPD), Isoenzimas e Microssatélite. Os resultados obtidos em seis populações pela técnica de RAPD baseados em 25 loci, revelaram uma heterozigosidade média de 0,262, com polimorfismo (P) variando de 52 a 84%. A diferenciação genética entre as populações foi extremamente elevada e significativa (GST = 0,258; p < 0,05), refletindo a existência de baixo fluxo gênico entre as mesmas (Nm = 0,72). A análise de cinco populações com 6 loci alozímicos mostrou uma heterozigosidade média de 0,212 e polimorfismo (P) variando entre 25 e 100%. O índice de diferenciação genética FST obtido por este marcador entre as populações correspondeu a 0,544 (p < 0,05), sugerindo a ocorrência de baixo fluxo gênico (Nm = 0,210) entre as populações. A heterozigosidade e o polimorfismo (P) observados em onze populações pela análise de 8 loci de microssatélites variaram entre 0,038 e 0,224 e de 37,5 a 75%, respectivamente. O FST entre as populações correspondeu a 0,220, produzindo um Nm de 0,8. Os três marcadores moleculares utilizados revelaram que as populações de A. grandis dos estados brasileiros avaliados apresentam baixa diversidade genética, em comparação às populações dos Estados Unidos, México e demais países da América do Sul, sugerindo que a colonização deste inseto ocorreu em uma ou poucas áreas. Os resultados obtidos relativos à diversidade genética também permitiram distinguir populações oriundas de regiões onde é praticada a agricultura em escala empresarial das áreas de agricultura familiar, assim como mostrou que as populações do nordeste podem estar servindo de fonte para colonização de novas áreas e de áreas já tratadas

A madeira é a principal variável de custo na produção de polpa celulósica. A polpa celulósica obtida a partir da madeira de folhosas é principalmente utilizada para produção de papéis de escrita e impressão assim como, a produção de papéis para fins sanitários; para estes usos normalmente a polpa celulósica deve ser branqueada. Mundialmente, várias espécies de madeira de folhosas são utilizadas para produção de polpa celulósica de fibra curta, estando entre as principais o híbrido Eucalyptus grandis x Eucalyptus urophylla (Brasil), Betula pendula (Finlândia) Eucalyptus globulus (Portugal). Este projeto teve por objetivo: i-avaliar e comparar o desempenho de madeiras de principais espécies utilizadas mundialmente, para produção de polpa celulósica de fibra curta, considerando os aspectos relacionados à qualidade da madeira e polpa, o consumo de reagentes químicos na polpação e também os aspectos relacionados ao rendimento e a capacidade de produção de polpa celulósica; ii-fornecer informações estratégicas para o setor celulósico nacional com relação as possíveis ameaças e as oportunidades apresentadas pelos materiais não utilizados no Brasil, visando o conhecimento e posicionamento em competitividade destas madeiras no mercado mundial de celulose e papel; iii-fornecer subsídios para o programa genético e de melhoramento florestal; iv-posicionar a polpa celulósica de Eucalyptus grandis x Eucalyptus urophylla em relação as suas principais concorrentes. Para realização deste trabalho foram coletadas 5 árvores de todas as espécies, sendo considerado o diâmetro médio do povoamento, transportando a madeira em forma de discos e transformadas em cavacos de forma manual; com relação à madeira foram determinadas, densidade básica, dimensões de fibras, composição química e análise anatômica através da microscopia eletrônica de varredura; as condições de cozimento foram ajustadas visando à obtenção de polpa branqueável (número kappa de 17&#177;0.5). Os resultados obtidos mostraram que as espécies de Eucalyptus globulus e E. grandis x E. urophylla 2 apresentaram melhor desempenho no processo de polpação; atingiram a mesma intensidade deslignificação (expressa como número kappa), sendo necessário menor nível de álcali ativo. As matériasprimas citadas apresentaram maior rendimento, maior viscosidade e menor teor de ácidos hexenurônicos. As diferentes matérias-primas estudadas neste trabalho apresentaram características bastante distintas que implicam em diferentes eficiências nos processos de polpação e branqueamento. / Wood is the main variable in the cost of pulp production, besides being a strong component in the final quality of the paper product. Pulps obtained from hardwoods are mainly used in the production of printing and writing papers as well as tissue papers; for these uses, the pulp must be bleached. Several species of hardwoods are used in the production of pulp worldwide. The main ones are the hybrid Eucalyptus grandis x Eucalyptus urophylla (Brazil), E. globulus (Portugal), Betula pendula (Finland). The objectives of this research was: 1) to evaluate and compare the performance of woods from the main species used worldwide for hardwood cellulose pulp production, considering the aspects regarding the quality of the wood and pulp, chemicals consumption during pulping, and aspects related to the yield and capacity pulp production; 2) to supply strategic information for the Brazilian pulp and paper sector regarding possible threats and opportunities presented by materials which are not used in Brazil in order to know and compete with these woods in the world market of pulp and paper. In order to accomplish this work, chips were manually obtained from disks. Regarding the wood, the basic density, fibers dimensions, chemical composition and anatomic analysis were conducted. The cooking conditions were adjusted in order to obtain the bleachable pulp (kappa number 17&#177;0.5). The results had shown that the species of Eucalyptus globulus from Portugal and hybrid of Eucalyptus grandis x Eucalyptus urophylla 2 had better performance in the kraft pulping process; they had reached the same delignification level, as number kappa, requiring lesser active alkali. The mentioned raw materials showed higher yield, greater viscosity and minor levels of acid hexenurônicos. The raw-materials considered in the research showed clearly distinct characteristics that lead to differences in the pulping and bleaching processes efficiencies and strategies.

Dans l’hémisphère Nord, le climat des deux derniers millions d’années a été marqué par une alternance de périodes froides et de brefs intervalles chauds. Cette succession d’évènements a laissé des traces durables au niveau de l’arrangement spatial de la diversité et de la structure génétique au sein des espèces.<p>En décrivant la répartition spatiale des lignées d’une espèce au moyen d’informations génétiques, la phylogéographie vise à identifier les processus évolutifs responsables de cette répartition. La phylogéographie comparée permet de gagner en compréhension en confrontant les patrons de variation génétique présents chez plusieurs espèces codistribuées :en étudiant des espèces partageant une même histoire au moyen de plusieurs sources d’information indépendantes (par exemple, plusieurs fragments d’ADN ou des données bioclimatiques historiques externes), il est possible de mettre en évidence des éléments de cette histoire commune tels que des refuges glaciaires ou des routes de recolonnisation post-glaciaires. Par contre, il est aussi possible que les caractéristiques biologiques intrinsèques à chaque espèce, telles que des stratégies dispersives ou reproductives différentes, engendrent une différenciation dans la structure et la diversité de cette variation génétique. <p>Dans cette thèse de doctorat nous nous sommes intéressés à deux espèces inféodées à un même hôte (Picea abies) et appartenant à une même sous-famille taxonomique (Coleoptera :Curculionidae, Scolytinae). Il sagit du typographe, Ips typographus et du dendroctone, Dendroctonus micans. Au moyen de plusieurs fragments génétiques spécialement identifiés pour cette étude ainsi que par le recours à des modèles bioclimatiques et des tests statistiques basés sur la théorie de la coalescence, nous avons étudié la phylogéographie de ces espèces.<p>Les résultats obtenus au cours de ce travail ont permis de mettre en évidence l’influence contrastée de stratégies écologiques différentes sur l’arrangement de la variation génétique. Une espèce opportuniste aux capacités de dispersion élevées telle qu’I. typographus présente un patron génétique peu structuré (des variants génétiques appelés haplotypes sont présents dans des régions très disparates) et un degré de polymorphisme nucléaire relativement élevé. Au contraire, une espèce parasitique adaptée à un environnement stable et caractérisée par une stratégie de dispersion limitée telle que D. micans présente un patron génétique très structuré (un nombre restreints et spécifiques d’haplotypes sont observés dans des régions géographiquement proches) et un degré de polymorphisme nucléaire dramatiquement faible.<p>Par ailleurs la comparaison de nos résultats à ceux de leur hôte, l’épicéa, ainsi qu’à ceux d’autres espèces partageant une même niche écologique (ex. Rhizophagus grandis), nous a permis de mettre en évidence des éléments communs dans l’histoire de ces espèces boréo-montagnardes :les populations européennes et asiatiques présentent une même divergence ancienne (antérieure à la dernière glaciation) et les populations européennes affichent des traces de structure génétique. Ces éléments nous ont permis de reconsidérer l’histoire de ces deux espèces en proposant et testant de nouveaux scénarios historiques./In the North Hemisphere, the climate of the last two million years has been paced by<p>the alternation of ice ages and warm interglacial periods. This succession of events has markedly shaped the present-day spatial arrangement of genetic diversity and structure within species. <p>By analyzing the geographical distribution of genetic variation within species, Phylogeography aims to identify evolutionary processes responsible for the current spatial patterns in the distribution of populations. Comparative phylogeography is used to gain insights into the understanding of driving evolutionary processes by co-analyzing the current genetic variation patterns of several co-distributed species; the study of species sharing a same history by several independent sources of information (e.g. different DNA fragments or historical bioclimatic data) allows to identify similar historical events such as glacial refugia or post-glacial recolonization pathways. However differences in life-history traits related to specific ecological strategies may also influence contrasting patterns of genetic structure and diversity. <p>In this PhD thesis, we focused on two insect associated with a same host (Picea abies) and belonging to a same taxonomic sub-familly (Coleoptera :Curculionidae, Scolytinae). The two insects are the Eurasian spruce bark beetle, Ips typographus, and the great spruce bark beetle, Dendroctonus micans. By the use of several genetic markers specifically designed for the purpose of this study and by bioclimatic modeling approach combined with coalescent-based statistical method, we have studied the phylogeography of both species. <p>Our results enable us to highlight the influence of contrasting ecological strategies on the spatial arrangement of genetic variation. On the one hand, opportunistic species characterized by high dispersal capacities, such as I. typographus, exhibits poor genetic structure (same genetic variants named haplotypes are found in really distant geographic regions) and a relatively high polymorphism level. On the other hand, parasitic species well-adapted to stable environmental conditions and characterized by limited dispersal strategy, such as D. micans, exhibits high genetic structure (same specific haplotypes found in same or neighboring geographic countries) and an extremely low polymorphism level.<p>Moreover, the comparison of our results with those of their specific host plant Picea abies and of other sympatric species (e.g. Rhizophagus grandis), has enable us to identify common patterns typical of boreo-montane species :a same old divergence between european and asiatic populations (older than the last glaciation) and genetic structure in european populations. These findings have been used to infer past of both species by identifying and testing new historical scenarii.<p><p> / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished