Knowledge of the potential productivity of a tree species becomes especially important when timber production is the primary management objective. However, direct determination of potential productivity is often not possible. For example, in situations where the site is unstocked, stocked with trees unsuitable for productivity measurement, or stocked with species other than the one of interest. In these cases, an indirect estimate using known characteristics of the site itself is required. Such estimates were made using regression to model site index with indirect measures of site quality for lodgepole pine (Pinus contorta) and interior spruce (Picea engelmannii × P. glauca) in the Sub-Boreal Spruce (SBS) zone of central BC. We tested the utility of these productivity relationship models for predicting the site index of lodgepole pine and interior spruce (Kayahara et al. accepted for publication).

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 2000. / Document électronique également accessible en format PDF. CaQCU

Thèse (M.Ress.Renouv.) -- Université du Québec à Chicoutimi, 2004. / Bibliogr.: f. 62-73. Document électronique également accessible en format PDF. CaQCU

Thesis (Ph. D.)--Australian National University, 2004. / Title from PDF title page (viewed on July 2, 2005). Includes bibliographical references (p. 172-196).

Thesis (M.S.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

As regiões de cultivo de eucalipto apresentam um grande número de variações ambientais em nível microrregional, como pode ser facilmente constatado quando se observam as diferenças expressivas entre as produtividades florestais de cada área. No entanto, para se avaliar um ambiente, é necessário identificar segmentos específicos dentro de uma paisagem, tratando-se de uma propriedade florestal e, dentro desse estudo, buscar a compreensão das interações que aí se processam. Este trabalho contribui para entender o efeito da face de exposição solar no crescimento de plantios comerciais de Eucalyptus. A proposta metodológica apresentada leva em consideração o conhecimento do meio físico - tendo como base a fisiografia para distinção das faces de exposição solar- além disso, a interação dos fatores fisiográficos com os fatores biológicos são discutidos para subsidiar a tomada de decisão. A acentuada interação genótipo x ambiente presente em muitas culturas faz com que estudos de adaptabilidade a ambientes específicos sejam parte integrante dos programas de pesquisa florestal. A resposta diferenciada dos genótipos a ambientes favoráveis e desfavoráveis pode auxiliar o gestor florestal na alocação assertiva dos materiais genéticos para maximizar a produtividade. O escaneamento a laser aerotransportado, ferramenta de uso precoce no Brasil, é um sensor óptico ativo que mede a distância até os objetos-alvo e foi utilizado para a obtenção da altura das árvores. A área de estudo está localizada na região sudoeste do estado de São Paulo. Dentre as métricas disponíveis do processamento utilizou o percentil 90 de altura para estimar a altura de plantios comerciais homogêneos de Eucalyptus. Elaborou-se a análise de variância considerando um delineamento fatorial contemplando a face de exposição solar (norte e sul) e o material genético (clones comerciais), além da interação entre ambos para observar o efeito da face no crescimento em altura do povoamento. Para florestas abaixo de quatro anos de idade observou-se que os plantios de face sul cresceram menos que os da face norte. Para florestas acima de 5 anos essa diferença entre face continua, contudo, quando concluído o desdobramento da interação fatorial observou-se que os materiais genéticos plantados em face norte não diferem entre si, mas a diferença se mantém para florestas em face sul. / The eucalyptus cultivation regions boast a large number of environmental variables in micro-regional level, as can easily be seen when studying the expressive differences between the productivity of each forest area. To evaluate an environment, however, it is necessary to identify specific segments within a landscape with regards to a forest property and within that landscape study to seek the understanding of the interactions that takes place in the process. This work contributes to a better understanding of the effect of the aspect on growth in commercial plantations of Eucalyptus. The methodological approach presented in this work takes into account the knowledge of the physical environment, based on physiography, for distinction of aspect on environments, in addition to showing the interaction of physiographic factors with biological factors to support the decision-making process. The sharp interaction genotype x environment present in many cultures leads to studies of adaptability to specific environments to become integral parts of forestry research programs. The differentiated response of genotypes to favorable and unfavorable environments can assist forest managers in the allocation of assertive genetic materials to maximize productivity. The airborne laser scanning, which is an early tool used in Brazil, is an active optical sensor that measures the distance to the target objects, was used to obtain the height of the trees. The study area is located in the southwestern region of the State of São Paulo in Brazil. Among the available processing metrics, it was used 90 percentiles in height to estimate the height of homogeneous commercial plantations of Eucalyptus. A variance analysis was devised considering a factorial design contemplating the aspect (North and South) and genetic material (commercial clones), besides the interaction between both to observe the effect of the exposure on the height growth of the settlement. To forests below four years of age, it was observed that the plantations of the South exposure grow less than the north exposure. For forests above five years, this difference between aspect continues, however, when the deployment of factorial interactions is done, it\'s observed that the genetic materials planted in the north exposure do not differ with each other, but the difference stands within forests in the South exposure.

Orientador: José Raimundo de Souza Passos / Resumo: O setor de florestas plantadas no Brasil, e particularmente de eucaliptos, tem significativa participação na produção nacional representando 1,3% do PIB. O acirramento da competição entre as empresas de base florestal faz com que estas busquem por alternativas para minimizar o aumento dos custos produtivos aliadas ao aumento da produtividade de suas florestas plantadas. No entanto, um dos aspectos da garantia desta produtividade está relacionada à fitossanidade das florestas plantadas. Neste sentido, o objetivo deste trabalho é quantificar o efeito da ferrugem, causada por Austropuccinia psidii Winter na produtividade de povoamentos do Eucalyptus grandis utilizando uma abordagem de modelagem estatística. Inicialmente, foi proposto um novo Índice de Severidade da Ferrugem (ISF) com o objetivo de quantificar o efeito da doença no tempo, definido como a média ponderada entre as categorias de severidade com o inverso da idade das árvores. Ajustaram-se os modelos lineares generalizados com o objetivo de verificar o efeito dos fatores “fazenda” e “severidade” da doença (doente/sadia) no volume máximo amostral (m3). Foram também ajustados modelos de regressão linear generalizados para verificar o efeito do ISF no volume máximo amostral (m3) das árvores. As curvas de crescimento das árvores por região/fazenda foram ajustadas utilizando-se modelo de regressão não linear Gompertz. Após os ajustes, foram estimados os volumes das árvores aos 51, 60, 66 e 72 meses de idade para cada uma d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The planted forest sector in Brazil, and particularly eucalyptus, has a significant participation in national production, representing 1.3% of Gross Domestic Product. The increased competition among forest-based companies makes them search for alternatives to minimize the increase in production costs combined with the increase in the productivity of their planted forests. However, one aspect of ensuring this productivity is related to the health of planted forests. In this sense, the aim of this paper is to measure the effect of rust disease, caused by Austropuccinia psidii Winter on the productivity of Eucalyptus grandis stands by the statistical modeling approach. Initially, a new Rust Severity Index (ISF) was proposed in order to quantify the effect of the disease over time, defined as the weighted average between the severity categories with (or and) the inverse of the age of the trees. The generalized linear models were adjusted in order to verify the effect of the factors "farm" and "severity" of the disease (sick / healthy) on the maximum sample volume (m3). Generalized linear regression models were also adjusted to verify the effect of the ISF on the maximum sample volume (m3) of the trees. The growth curves of the trees by region / farm were adapted using a non-linear Gompertz regression model. After the adjustments, the tree volumes at 51, 60, 66 and 72 months of age were estimated for each of the severity categories (sick / healthy). In this way, the percentage dif... (Complete abstract click electronic access below) / Doutor

Equations for modeling the height-age pattern of forest trees or stands are typically developed for a given species in a specified region. In order to adequately model height-age patterns, the resulting equations are often quite complex. This study addresses the question of how to increase the accuracy and precision of the prediction of height-age relationships through the use of localized equations. Although the pattern of height-age relationships of loblolly pine plantations was studied, the methodology should prove valuable for other species as well. The Schumacher logarithm of height-reciprocal of age model was fitted to data from loblolly pine plantations to attain an average guide curve. Various methods of localizing this equation to a particular stand were examined. The methods are based on empirical Bayesian, maximum likelihood, and Kalman filter theory. All of these methods employ the general concept of feedback in localizing the simple equation. The best of these various models is compared with the unadjusted model and a more complex polymorphic equation. The adjusted model compares favorably with these other two models. / Master of Science

Two mathematical models (TASS and PT AEDA2) were applied to the study of long-term interactions of air pollution stress and forest growth and yield. TASS was previously developed to examine the dynamics and yield of Douglas-fIr, and PTAEDA2 was previously developed to examine individual tree growth and stand development in loblolly pine plantations. Differential levels of pollution stress were incorporated into TASS through the reduction of the input variables photosynthetic efficiency and average needle retention. Reductions of photosynthetic efficiency included 0, 7.5, and 15 percent, while average needle retention was reduced 0 and 1 year. These reductions were distributed evenly over each of the five most current years' needles. Percentage volume reductions of 0, 17.3, 4.4, 23.1, 16.0, and 32.4 were obtained as results from six TASS scenarios. Given these percentage volume reductions, several levels of crown ratio reduction (0, 5, 10, 12, 15, and 22 percent) were applied to PTAEDA2 in order to determine the crown ratio reductions necessary to cause the same percentage volume reductions obtained from TASS. Results indicate that crown ratio reductions of 0, 5, 10, 12, 15, and 22 caused total volume reductions of 0, 6.3, 14.9, 18.7, 22.6, and 33.3 percent. These results are not intended to be final quantitative answers to the question of possible volume reductions due to air pollution impacts. However, they do offer insights to the possible effects of air pollution stress on forests. / Master of Science

The effects of site quality, dormant and growing season harvests, and four even-aged regeneration treatments on natural hardwood and planted loblolly pine (Pinus taeda L.) are examined three years after clear felling and whole-tree harvesting upland hardwood stands in the Virginia Piedmont. Natural hardwood regeneration was dominated by stump sprouts, with seedlings and advanced regeneration playing a secondary role. Stump sprouts and seedlings plus advanced regeneration were significantly taller with a dormant season harvest. A growing season harvest resulted in significantly better survival and growth of loblolly pine after 2 growing seasons. A trend for more loblolly pine volume index growth on the poor site class was noted. Regneration alternatives included an herbicide stump treatment at time of harvest that significantly reduced stump sprout growth, 70%, and resulted in significantly better loblolly pine survival. This stump sprout control also favored hardwood seedling and advanced regeneration. One regeneration alternative included either a triclopyr basal bark spray or hexazinone soil applied spot treatment for releasing loblolly pine at age one. Both release treatments significantly reduced natural regeneration basal area and density when used two years after the herbicide stump treatment. Loblolly pine growth was significantly increased by both pine release treatments. Herbicide treatments were most effective, in terms of lower hardwood basal area and greater loblolly pine volume index, in growing season harvest treatment plots. / Master of Science