ABSTRACT Background: Process-based modeling is made to simulate the interactions of the soil-plant-atmosphere system providing information and estimates for forest management and services. Through bibliometric evaluation we identify the quantitative state of the art on the use of Process-Based Models (PBMs) applied in forestry studies, contextualizing research fronts, and analyzing the main topics and emerging themes. Data from the Web of Science and Scopus were used for the bibliometric survey of 533 scientific records. Results: We verified that (i) the number of publications related to the PBMs was boosted in the year 2000, and is growing; (ii) Forest Ecology and Management (74 publications) is the journal that most publishes on the subject; (iii) Annikki Mäkelä is the most productive researcher (20 publications) and most cited (h-index: 12); (iv) The USA (131 records) is the country with the highest number of research; (v) there are eight collaborative networks between the authors, three workings together, and five producing in isolation; (vi) the keywords are grouped into five clusters: (a) the effect of climate change on forests; (b) carbon studies; (c) physiology of trees; (d) silvicultural practices and; (e) analysis of model uncertainties. The separation of themes showed that the new search hotspots are the PBMs using of remote detection tools. Conclusion: The results presented can be a fundamental theoretical tool for understanding the trends and development perspectives of this research line in future studies.

ABSTRACT This study aimed to evaluate the growth of Eremanthus erythropappus (DC.) MacLeish submitted to different planting spacing and growth modelling based on the diameter and crown area projection, as well as to identify the best management strategy to be applied to control the competition, period and intensity of thinning. The evaluated planting spacings were: 1.5 × 1.5 m; 1.5 × 2.0 m; 1.5 × 2.5 m and 1.5 × 3.0 m. Diametric growth modelling in function of the age and crown area projection according to the mixed models methodology was efficient and the individual tree modelling allowed for defining a correct thinning prescription for tree plantations in relation to the percentage of removal needed at each spacing, thus permitting the trees to grow free from competition and produce trees with larger diameters.

RESUMO Objetivo do trabalho foi estabelecer equações hipsométricas para Eucalyptus spp. não manejado em idade avançada. Para isto, foram mensurados o diâmetro e a altura de 513 fustes distribuídos em 11 espécies e ajustes hipsométricos foram testados por seis modelos de regressão, sendo selecionado aquele com os melhores valores de Critério de Informação de Akaike (AIC), Erro Padrão da Estimativa (Syx), teste de Razão de Máxima Verossimilhança e Análise Gráfica de Resíduos. Posteriormente, o melhor modelo foi submetido à inclusão de covariantes, Qualidade do Fuste (Qf) e Espécie (Sp), por meio da decomposição dos seus parâmetros. Nessas condições, o modelo de Chapman e Richards se mostrou o de melhor desempenho tanto em sua forma original, quanto após a inclusão das covariantes, sendo que, ao compará-los obteve-se uma redução no modelo com covariantes de 71 unidades em AIC, 7,4% em Syx e melhoria significativa em todos os aspectos da distribuição de resíduos. Portanto, foi possível estabelecer equações hipsométricas adequadas para eucalipto não manejado em idade avançada, com e sem inclusão de covariantes, sendo que a última técnica resultou em melhoria significativa na qualidade do ajuste.

ABSTRACT The aim of the study was to establish hypsometric equations for unmanaged Eucalyptus spp. in old age. For this purpose we measured the diameter and height of 513 stems distributed in 11 species and the hypsometric relationship was established by six regression models, being selected the one with the best Akaike Information Criterion (AIC), standard error of estimative (Syx), Maximum Likelihood Ratio Test and Residual Graphical Analysis. Subsequently, the best model has undergone the inclusion of the covariates stem quality (Qf) and Species (Sp) by means of the decomposition of its parameters. Under these conditions, the model of Chapman and Richards showed the best performance in both modeling approaches. When compared both models, we observed a reduction of 71 AIC units and 7.4% in Syx and a significant improvement in all aspects of the residual distribution in the model with covariates. The results show that it is possible to provide hypsometric equations suitable for unmanaged Eucalyptus in old age, with and without addition of covariates, and the last technique has provided significant improvement in the quality of fit of the models.

Existem importantes fatores ambientais que afetam diretamente a taxa de crescimento das espécies florestais, que podem provocar alterações em suas propriedades e, por sua vez, afetar a densidade da madeira. Como a ocorrência das diferentes fitofisionomias está relacionada a fatores ambientais característicos, neste trabalho, objetivou-se verificar o comportamento geral da densidade da madeira das espécies arbóreas nativas, frente a essas diferentes condições de crescimento no estado de Minas Gerais. Os dados de cubagem rigorosa das árvores foram obtidos do Inventário Florestal de Minas Gerais. Foram utilizados dados de 1988 árvores nas diversas fisionomias florestais. De cada árvore foram retirados cinco discos de madeira nas posições 0, 25, 50, 75 e 100% da altura total. A densidade básica de cada disco foi determinada segundo a norma NBR 7190/1997. As fitofisionomias ombrófila, semidecídua, cerradão, cerrado típico e decídua apresentaram, respectivamente, médias de densidade da madeira de 0,502; 0,561; 0,585; 0,612 e 0,675 g.cm-3, todas estatisticamente distintas. Foi encontrada uma relação clara e coerente da densidade da madeira com as características edafoclimáticas que condicionam as diferentes fitofisionomias no estado de Minas Gerais. As fisionomias florestais apresentam condições ambientais tão características, que afetam a composição florística e, também, a atividade fisiológica e cambial das plantas, ocasionando densidades da madeira próprias às formações florestais.

The objective was to verify the general behavior of wood density of native tree species in forest types in Minas Gerais state. The trees scaling data were obtained from the Forest Inventory of Minas Gerais State. Were used data from 1988 trees distributed in different forest formations. From each tree, five discs of wood were removed, at the 0, 25, 50, 75 and 100% of the total height. The wood basic density of each disk was determined according to NBR 7190/1997. The ombrophylous forest, semideciduous forest, savanna woodland, typical savanna and deciduous forest presented average wood density of 0.502, 0.561, 0.585, 0.612 and 0.675 g.cm-3, respectively, all statistically different. It was found a clear and consistent relation between wood density and environment characteristics that affect the different vegetation types in Minas Gerais State. The forest formations present environmental conditions so typical that they affect the floristic composition and also the cambial and physiological activity of plants, causing particular wood densities to forests formations.