RESUMO A eficiência econômica do sistema de colheita depende de vários fatores como: condições geomorfológicas e climáticas das áreas de corte, características das árvores a serem colhidas, tipo de maquinário utilizado e características da mão de obra. Portanto, decide-se com base no uso de novas tecnologias, otimizando o processo de corte e transporte de madeira, e especificamente, otimizando o custo do sistema de colheita, selecionando o sistema de colheita florestal mais adequado para a área de estudo. registro para análise de custos e avaliação financeira. Para o estudo de caso, as florestas naturais de Pinus caribaea var. caribaea em áreas da Companhia Agroflorestal Macurijes na província de Pinar del Río. O aplicativo (COSTOFOR) possui dois módulos de trabalho: custos do sistema de colheita e análise financeira de todo o processo de colheita. Na análise dos custos são aplicados critérios de optimização que permitem minimizá-los, destacando-se acima destes critérios aquele relacionado com a interacção entre o custo da estrada e o custo de transporte com base na densidade de estradas e pátios de carregamento. Para a análise financeira, são aplicados indicadores para definir a viabilidade do projeto e a rentabilidade do investimento, cujos resultados permitem a tomada de decisões.

ABSTRACT The economic efficiency of the harvesting system depends on several factors such as geomorphological and climatic conditions of the felling areas, characteristics of the future harvested trees, type of machinery used and the characteristics of the workforce. Therefore, based on the use of new technologies, it is decided to optimize the process of felling- stockpiling-wood transportation, and specifically, to optimize the cost of the harvesting system, select the most appropriate forest harvesting system for study area and develop a computerized record for cost analysis and financial evaluation. For this study, the natural forests of Pinus caribaea var. caribaea, in areas near Macurijes Agroforestry Company in the province of Pinar del Río, were examined. The application (COSTOFOR) has two work modules: harvesting system costs and financial analysis of the entire harvesting process. In the analysis of the costs, optimization criteria are applied to minimize them. Above these criteria stands out the one related to the interaction between the cost of the road and the cost of hauling based on the density of roads and loading yards. For the financial analysis, indicators are applied to define the feasibility of the project and profitability of the investment; the results of those indicators allow decisions to be made.

RESUMEN La eficiencia económica del sistema de aprovechamiento depende de varios factores tales como: condiciones geomorfológicas y climáticas de las áreas de tala, características de los árboles a aprovechar, tipo de maquinaria utilizada y las características de la mano de obra. Por lo que se decide a partir de la utilización de las nuevas tecnologías, optimizar el proceso de tala acopio transporte de la madera, y de manera específica, optimizar el costo del sistema de aprovechamiento, seleccionar el sistema de aprovechamiento forestal más adecuado para el área de estudio y elaborar un registro informático para el análisis de los costos y su evaluación financiera. Para el estudio de caso se tomaron los bosques naturales de Pinus caribaea var. caribaea en áreas de la Empresa Agroforestal Macurijes en la provincia de Pinar del Río. La aplicación (COSTOFOR) cuenta con dos módulos de trabajo: costos del sistema de aprovechamiento y análisis financiero de todo el proceso de aprovechamiento. En el análisis de los costos, se aplican criterios de optimización que permiten minimizar los mismos, destacándose por encima de estos criterios el relacionado con la interacción entre el costo de camino y el costo de arrastre en base a la densidad de caminos y patios de carga. Para el análisis financiero se aplican indicadores para definir la viabilidad del proyecto y rentabilidad de la inversión, cuyos resultados permiten tomar decisiones.

ABSTRACT This work was carried out in a teak plantation in the state of Mato Grosso, Brazil. The objective was to evaluate technical and economic indicators of the cutting and processing of trees with a track harvester. Twenty complete work shifts were evaluated using direct thinning to determine operational cycle times. Other information was also recorded for the calculation of production costs. The second thinning was performed at 12 years, with a volume of 0.1648 m³/tree, and the third thinning at 18 years with 0.3408 m³/tree. The main finding was an increase in productivity and decrease in production costs with rising tree volumes. For each hour of effective work, 53 trees were cut (339 trees/day), and processed into 1,047 logs. The decrease in the cost of cutting and processing trees in proportion to the increase in the average volume of trees to be extracted was confirmed.

ABSTRACT The objective was to obtain a statistical model to estimate the operational performance of cutting trees with a chainsaw in the natural tropical forest north of Mato Grosso state. One-hundred-and-fifty-one operational cycles of selective logging for commercial purposes were registered. In each cycle, the effective time for cutting, the diameter of the trees, commercial height, the number of logs per tree, and the distance between trees was determined. A step-by-step regression analysis was performed to obtain the coefficients of the models and statistical parameters. The result of the analysis concluded that the most accurate model to estimate the operational performance is the one that transforms the diameter variable at breast height (DBH) squared and also includes the variables number of logs per tree and distance between logged trees.

The work was carried out in natural forests of Pinus caribaea in areas of the forest company "La Palma" in the province of Pinar del Río in Cuba. The objective of the investigation was to minimize the cost of harvesting by combining the costs of haulage and road and load patio densities. In addition, the study also takes into consideration the interaction of costs of transportation and the thickness and quality of the layer of gravel on the road. The results of the investigation have shown a significant increase in the spacing between roads and load patios with the decrease of US$0.45/m³. It was possible to improve the quality of the layer of gravel on the road without changing the construction costs significantly, which led to a cost reduction of US$1.01/m³. The overall cost considering the new system decreases in US$1.46/m³. Another significant contribution is made by decreasing the impact to the ecosystem once the reduction on road density may reach around 44% in comparison to the current density.

El trabajo se realizó en bosques naturales de Pinus caribaea en áreas de la empresa forestal La Palma en la provincia de Pinar del Río - Cuba. El objetivo de la investigación fue minimizar el costo del sistema de aprovechamiento de madera a partir de la interacción entre el costo de camino y el costo de arrastre en base a la densidad de camino y patios de carga, además de la interacción del costo de camino y el costo del transporte de madera en base a la calidad de la capa de rodamiento del camino. Los resultados de la investigación muestran una reducción de la densidad de caminos y patios de carga, con la correspondiente disminución del costo de sistema de aprovechamiento de 0,45 $/m³. Además se logró mejorar la calidad de la capa de rodamiento del camino sin alterar el costo total de construcción de este, propiciando una disminución de 1,01 $/m³ de madera transportada. En general, el costo del sistema de aprovechamiento se reduce en 1,46 $/m³. También se hace una contribución considerable en la disminución del impacto al ecosistema al reducir 44% el área utilizada para la construcción de caminos y patios en relación al método tradicional.

Este estudo objetivou avaliar o desempenho de fornos retangulares no processo de carbonização, envolvendo duas rotinas de carbonização. As rotinas analisaram a influência de tatus e câmaras de combustão externa no processo de carbonização em quatro fornos retangulares instrumentados com termopares para acompanhamento da temperatura, bem como o balanço de massa e energia do sistema. A lenha utilizada na carbonização foi o clone A08, híbrido do cruzamento entre Eucalyptus grandis e Eucalyptus urophylla, com idade de 7 anos e comprimento da lenha de 3 m. Foram realizadas oito carbonizações em cada rotina. De acordo com os resultados, verificou-se que a rotina 2, caracterizada pelo uso das câmaras de combustão externa, foi mais eficiente no controle da carbonização; a instrumentação do forno é uma técnica viável, mas que requer ajustes para caracterizar, com precisão, o fenômeno da carbonização. No balanço de massa e energia, verificou-se que as perdas foram maiores que os ganhos em produção, para lenha com elevados teores de umidade.

The objective of the present work was to evaluate the performance of rectangular kilns in the carbonization process involving two carbonization routines. The routines analyzed the influence of air inlets and external combustion chambers on the carbonization process in four rectangular kilns equipped with thermo pairs for following temperature and mass and energy balance of the system as well. The firewood used in carbonization was the A08 clone, Eucalyptus grandis and Eucalyptus urophylla hybrid, at 7 years of age and 3 meters of wood length. Eight carbonizations were made for each routine. According to the results, it was verified that routine 2, which uses external combustion chambers, was more efficient for the carbonization control; Kiln instrumentation is a viable technique, but it requires adjustments for a precise characterization of the carbonization phenomenon. For mass and energy balance, it was verified that production losses were greater than profits for high moisture content firewood.

The work was carried out in natural stand of Pinus caribaea var. caribaea located in San Andrés, Forestry enterprise of La Palma in the Pinar del Río province. The objective was determine which method of wood extraction results more efficient and reduce damages to the soil vegetable. Three method were evaluated: 1- the extraction of tree length with oxen to landing; 2 - the extraction of tree length with tractor to landing; 3 - the extraction of tree length with oxen to short distance and using tractor up to landing places. The method the extraction of tree length with oxen to short distance and using tractor up to landing places, resulted the most efficient and the one which fewer damages on the vegetable cover of the soil.

El trabajo se realizó en rodales naturales de Pinus caribaea var. caribaea, ubicados en la unidad silvícola San Andrés, La Palma, provincia Pinar del Río. El objetivo de la investigación fue evaluar la eficiencia y los daños causados a la cubierta vegetal del suelo durante la operación de arrastre de madera. Se evaluaron tres métodos: 1 - el arrastre de fustes enteros con yuntas de bueyes hasta los patios de carga; 2 - el arrastre de fustes enteros con tractor hasta los patios de carga; 3 - el arrastre de fustes enteros con yuntas de bueyes hasta las pistas de arrastre y con tractor hasta los patios de carga. El método de arrastre de madera que consistió en la combinación del empleo de animales y de tractor resultó más eficiente y provocó menos alteraciones a la cubierta vegetal del suelo.

An study was carried out in the natural forests of Pinus caribaea, Pinar del Rio province, Cuba, aiming at the evaluation of the different methods used for clearcuting with chainsaw, using the cut-to-length system conducted in such a way to diminish the risks of the occupational diseases in chainsaw operators, and simultaneously to maintain the productivity levels and work quality. The rotation of the work was tested with an alternation controled method by refueling the chainsaw (MAC), and a free alternation method too (MAL). Both methods used: two chainsaw operators, the lever, and the directional felling in those trees exhibiting more than 40cm diameter. These methods were compared to each other, and to that one traditionally applied on natural forests (T), that consists of one operator and its assistant who besides maintaining their functions during this activity, do not use the lever nor make the directional felling, but rather adopt spontaneous pauses. According to the results, the MAC shows to be more appropriate because: it allows to reduce the risks of accidents and occupational diseases in chainsaw operators; provides the balance of the work physiologic load and the decreases of 13.69% in load and 52.08% in the noxious effects from chainsaw, although the productivity over the effective time showed an increase of 27.32% relative to method (T), so diminishing the operating costs that justify the basic wages corresponding to the operator's level for both integrants of the team.

El presente trabajo fue desarrollado en bosques naturales de Pinus caribaea, en la provincia de Pinar del Río-Cuba, para evaluar diferentes métodos en el corte raso con motosierra, empleando sistema de madera corta. Se experimentó la rotación del trabajo de un método de alternancia controlada de los operadores por el reabastecimiento de combustible de la motosierra (MAC) y un método con alternancia libre (MAL). En ambos métodos se utilizaron dos operadores en parejas, la palanca de empuje y la ejecución de la muesca direccional en árboles con diámetros superiores a 30 cm. Los métodos fueron comparados entre si y a su vez, con el que se aplica tradicionalmente en estas áreas (T), que consta de un operador y un ayudante que mantienen sus funciones durante la jornada, no usan la palanca de empuje, no efectúan la muesca direccional y toman descanso espontáneos. De acuerdo con los resultados el MAC es el más apropiado pues, redujo los riesgos de accidentes y enfermedades ocupacionales en los operadores de motosierras, al equilibrar y disminuir la carga fisiológica de trabajo en un 13,69%, redujo el tiempo de exposición a posturas incomodas, así como los efectos nocivos de la motosierra en un 52,08%, la productividad del tiempo efectivo se elevó en un 27,32% respecto al método (T), con la disminución de los costos de la operación, que justifican salarios básicos correspondiente al nivel del operador para ambos integrantes de las parejas.