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Aim of the study: We investigated the most suitable thinning ages and intensities to maximize productivity and minimize the rotation age of Tectona grandis clonal plantations in the Brazilian Eastern Amazon. Area of study: Capitão Poço, State of Pará, Eastern Amazonia, Brazil. Materials and methods: We used diameter, height, and volume data from 72 permanent plots measured on nine occasions. We determined the classification of forest sites using the generalized algebraic difference approach (GADA). Clutter’s segmented model was used to simulate different intensities of basal area reduction, determining the technical ages according to the projected increments. Main results: The polymorphic site curves generated by the GADA method revealed that there were sites with different productive characteristics. The Clutter model produced compatible projections of basal area and volume that followed the behavior of the productivity classes. The final production was maximized when three thinning intensities (basal area reductions) were applied: 1st thinning (50%), between the ages of 3.5 to 4.2 years; 2nd thinning (50%), between the ages of 6.1 to 7.3 years; and 3rd thinning (25%), between the ages of 10.6 to 12.8 years. Projected rotation ages ranged from 13.9 to 16.6 years earlier than seminal plantings. The simulations increased the net volume by 8.3%, on average, compared to no thinning. Research highlights: Simulations with three thinnings maximized production compared to the no thinning scenario. The time interval between thinnings was less than five years. The research results can help forest management decision-making and reveal production increases of T. grandis clonal stands in a shorter time.

In Brazil, affordable housing programs aimed at low-income populations reach a limited number of people. In the northern region, conventional bricklaying is the preferred method of building affordable single-family houses, which are essentially sets of tiny houses on the outskirts of cities. Conventional bricklaying can damage the environment. This study, started in July 2019, aimed to understand the perception of using timber to build affordable houses by housing program stakeholders and determine why the beneficiaries of housing programs prefer brick houses to wooden houses in locations with building permits. We applied a SWOT analysis to a group of 60 individuals comprising government agents and wooden and brick house residents of cities located in the northern region of Brazil. Subsequently, we devised relevant strategies, validated by stakeholders involved in public policy, for the provision of wooden housing for low-income populations. We used R software to analyze the data, and the results showed that the beneficiaries of affordable housing programs were unaware of wooden architectural projects and their durability, despite the regional abundance of wood and its environmental benefits. We suggest using strategies based on the SWOT analysis and validated by a group of experts to include the Affordable Wooden Housing (AWH) Project in the National Rural Housing Program (PNHR) and Harvest Plan.

We conducted a study on the dominant height growth of clonal teak (Tectona grandis Linn F.) plantations in the Brazilian Amazon to assess their potential and its agreement with volumetric production. We employed two approaches, ADA (algebraic difference) and GADA (generalized algebraic difference), and analyzed data from 58 permanent plots collected over a 10 year period. To classify the sites, we developed equations and evaluated their accuracy using various criteria, including correlation coefficient, mean square of residual, Akaike’s criterion, distribution of residuals, and validation through equivalence testing (TOST). We also assessed the biological realism of the constructed curves. We used cluster evaluation and dendrogram comparison to assess the agreement between site index and volumetric production for each approach. The Lundqvist–Korf baseline models (M1–ADA and M4–GADA) proved to be accurate and realistic in estimating dominant height in both approaches. Our findings indicate that the approaches utilizing dynamic equations and generating polymorphic curves effectively represent the sites and indicate the volumetric production of the plantations, with 98.3% of agreement rate. Based on our results, we recommend the use of ADA and GADA approaches for estimating the dominant height of clonal teak plantations in the Eastern Brazilian Amazon.

O Cerrado é o segundo maior bioma da América do Sul ocupando cerca de 23% do território nacional, mas que vem perdendo grande parte da sua vegetação nativa devido ao desmatamento e a fragmentação antrópica. O estudo teve como objetivo entender o comportamento de uma área restaurada no bioma por meio do prognóstico do fragmento florestal, a partir do método de razão de movimentação das classes. Foram realizados dois inventários florestais, onde foram mensurados todos os indivíduos com CAP (circunferência a altura do peito) superior a 15 cm, para posterior ajuste dos modelos não lineares de incremento periódico, ingresso e mortalidade. Os resultados demonstraram perda da densidade de indivíduos, indicando a passagem de fase do fragmento de “construção” “para “degradação”. Os principais fatores da degradação foram, a acessibilidade ao local, descarte de lixo urbano e a falta de planejamento do projeto de restauração, deixando de levar em consideração os princípios de sucessão ecológica e o levantamento das informações de referência do ambiente. Porém, a área apresenta capacidade de regeneração se forem adotadas técnicas que interfiram no processo de restauração, pois houve aumento na taxa do número de indivíduos na menor classe de diâmetro (2023) se comparado aos anos anteriores; aumento do crescimento na penúltima classe, seguido de estabilização; redução da perda de densidade dos indivíduos, entre os intervalos dos anos 2014-2017 e 2017-2023; e tendência de distribuição diamétrica em “J invertido” no ano de 2023.