Search

Tree cultivation spacing can influence productivity and wood quality, with silvicultural, technological and economic implications. This study aimed to estimate the production and provide an economic analysis of Eucalyptus urophylla × Eucalyptus grandis stands as a function of planting spacing in a small rural property. The study was carried out in the Zona da Mata of Minas Gerais state, with the hybrid clone (GG100) established in 2 × 1 m, 2 × 2 m, 3 × 2 m and 3 × 3 m spacing. Inventories were carried out at 14, 54 and 84 months in four plots from each spacing, with 24 plants. Diameter at breast height (DBH), total height and survival rate were evaluated. The study evaluated the logistic model of growth and yield for the different spacings and analysed production costs, characterising the expenditure elements related to inputs and labour. For the economic analysis, we considered a discount rate of 8% p.a. and the valuation methods of net present value (NPV), annual equivalent value (AEV), average production cost (APC), and cost–benefit ratio (CBR). Spacing influenced diameter distribution, tree height and productivity. The optimal harvest age showed a tendency to decrease in smaller spacing. The increase in plant density (smaller spacing) did not promote a proportional increase in volumetric production. Our results indicated economic viability from 60 months onwards for all spacing, except for 2 × 1 m. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) is a carbonaceous material used to adsorb and remove pollutants. One of the requirements for the material to be considered a precursor in the AC production is its high levels of carbon. Therefore, a promising alternative for the use of forest biomass and its residues would be the application of these materials as precursors in the AC production. Owing to the productive capacity of activated carbon in Brazil and the considerable availability of forest biomass, the objective of the study was to approach the production and market of activated carbon in Brazil. This study is a bibliographic review focused on the use of forest resources for the AC production. AC production occurs by three methods: physical, chemical and physico-chemical activation. At the national level, the main production method is the physical one, since it has the least cost. However, the Sector still requires the researches and technologies aimed at the standardisation and improvements in the whole production chain. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Minquartia guianensis Aubl. (acariquara) occurs at Acre, Amazonas, Roraima, Pará and Amapá states, with a great market demand and utility in the Amazon region. It is used mainly in civil construction due to its high durability and singular beauty, because of reentrances in its trunk, resulting in high market value. Most of used trees present small diameters, what is a critical factor for their management and commercialization. Thus, the objective of this study was to evaluate M. guianensis diametric growth and cutting cycle through the analysis of time of passage among diameter classes, 31 years after logging, at Tapajós National Forest, Pará State, Brazil. Five treatments were established and in each one 12 permanent sample plots of 0.25 ha were installed. All trees with diameter at 1.3 m above ground level (DBH) ≥ 5 cm were measured from 1981 to 2012. Trees with DBH ≤ 50 cm have potential to be managed, due to the growth stagnation presented in larger diameter classes. These results may support silvicultural decisions to sustainable management. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira is the property of Brazilian Journal of Forest Research / Pesquisa Florestal Brasileira and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Forest production regulation is complex due to the large number of variables in the process. Economic variables consistently influence the results of regulation models. Therefore this study aims to analyze the influence of interest rate and wood price in some forest regulation models. Linear programming model was used in a studying case using data from 10 forest stands and the software Regulation of Forest Production, which was also used to simulate management and planning scenarios. All stands were regulated independently of the method used. It was observed that as the wood price raises, the annual cutting area becomes bigger and the average logging age decreases. The average annual production presented no change regardless of interest rate, wood price or the method used. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Economia e Sociologia Rural is the property of Sociedade Brasileira de Economia e Sociologia Rural and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The existence of degraded forests is common in the Eastern Amazon. The maintenance of these forests standing and the recovery of their productivity play an important role in the conservation of biodiversity, storage and carbon sequestration. However, the management techniques currently employed are designed for natural forests in the first harvest cycle or lightly explored and do not apply adequately to forests that have gone through several harvest cycles. Therefore, adaptations and the establishment of new management criteria that take into account other characteristics of these types of forests are necessary to ensure their sustainability. The objective of this study was to propose a silvicultural management system that has the potential to recover and perpetuate the productivity of an intensively logged tropical forest. A forest census was carried out on 535.6 ha for trees with dbh ≥ 25 cm. With these data, the following two treatments were designed: (1) criteria: the BDq method was applied from B = 9.8 m2 ha−1, D = 100 cm and q = 2. The criteria for standing wood commercialization were, in this order, first, Health; second, Tree Stem; third, Tree Density and fourth, dbh ≥ 105 cm. (2) Control: the planning was in accordance with Brazilian regulations. For the cost–benefit and sensitivity analysis, the Net Present Value (NPV) was used and a projection of ±20% was made in the commercial price of standing wood. In the criteria treatment, a higher number of trees and species destined for the commercialization of standing wood was verified in relation to the control treatment, showing a greater diversity of species. In the criteria treatment, NPV was positive and superior to the control treatment in all scenarios. The proposed silvicultural management system with an object of an explored and enriched forest, with criteria for harvesting trees with a minimum cut diameter of 25 cm, proved to be viable to generate economic returns and with conservationist potential for the continuous supply of forest products and maintaining biodiversity. [ABSTRACT FROM AUTHOR]