scholarly journals AVALIAÇÃO TÉCNICA E DE CUSTOS DE PODA MANUAL E SEMIMECANIZADA EM PLANTIOS DE Pinus taeda

FLORESTA ◽  
2012 ◽  
Vol 42 (4) ◽  
pp. 691
Author(s):  
Felipe Martins Oliveira ◽  
Eduardo Silva Lopes ◽  
Jorge Roberto Malinovski ◽  
Rafael Henrique Da Silva ◽  
Carla Krulikowski Rodrigues

ResumoO objetivo desta pesquisa foi realizar uma avaliação técnica e de custos das atividades de poda manual e semimecanizada em plantios de Pinus taeda L., visando gerar informações para o aumento da produtividade, melhoria da qualidade e redução dos custos de produção. A pesquisa foi conduzida em uma empresa prestadora de serviços florestais, localizada na região do Norte Pioneiro, Estado do Paraná. Foram estudadas as atividades de podas executadas a 2,5 m; 4,0 m e 5,0 m de altura. A avaliação técnica consistiu em um estudo de tempos e movimentos, determinando a produtividade, a eficiência operacional e a qualidade das operações, verificando a presença de tocos de galhos e injúrias no lenho. A análise de custos foi feita por meio da determinação dos custos operacionais e de produção. Os resultados mostraram que a poda manual apresentou menor produtividade em relação ao método semimecanizado, porém proporcionou melhor qualidade do trabalho em termos de injúrias no lenho das árvores. Apesar do maior custo de produção, a execução das podas mais altas pelo método semimecanizado tornou-se viável técnica e economicamente devido à melhor qualidade do trabalho em relação à presença de tocos de galhos e possíveis benefícios ergonômicos aos trabalhadores. AbstractTechnical and cost evaluation of manual and semi-mechanized pruning in plantations of Pinus taeda. The objective of this research was to conduct technical and cost analysis of pruning in Pinus taeda L. planted forests by semi-mechanized and manual methods to increase productivity, improve the quality and reduction of costs. The research was conducted in a forest service company, located in the State of Parana, Brazil. There was studied the pruning to 2.5 m, 4.0 m and 5.0 m high. The technical evaluation consisted of a time and motion study, determining the productivity, operational efficiency and the quality of activities verifying the presence of branch stumps and injuries in the wood. The cost analysis was done by determining operating and production costs. The results showed that manual pruning had lower productivity compared to the semi-mechanized method, provided even better quality of work over terms apparent injuries on wood. Though even higher production cost, the implementation of pruning higher by semi-mechanized methods becomes more technical and economically, caused by better quality work in relation to the branch stumps and possible ergonomics benefits to workers.Keywords: Productivity; cost; pruning and silviculture. 

2020 ◽  
pp. 1259-1263
Author(s):  
Carlos Cézar Cavassin Diniz ◽  
Romano Timofeiczyk Junior ◽  
Renato Gonçalves Robert ◽  
Eduardo da Silva Lopes ◽  
João Carlos Garzel Leodoro da Silva ◽  
...  

In this work, we present that how bifurcation in Pinus trees can influence productivity and harvester production costs. Our example draws from one harvesting machine that works in thinning operations in forest plantations of Pinus taeda L. in a small Brazilian forestry company. To get daily productivity, we use the machine’s system, which provides such daily information as total production. We also used a time and motion study to obtain the meantime to cut, delimb, and process the tree stem into logs. In this way, we separated the normal trees from the forked trees to get the operating cycle time of the machine and get the productivity to the two types of trees. The continuous timing method was used for this purpose. The results show an increase of up to 22.9% in the operational cycle time for cutting forked trees, resulting in reduction of productivity of 5.58 m³ for each hour worked. The production cost increased by 23.3% on operation of forked trees, as the machine took more time to perform the partial activities of the operational cycle. This study can help many companies and contractors to calculate the appropriate productivity and production harvest cost according to the type of tree stems from the plantation forest.


FLORESTA ◽  
2020 ◽  
Vol 50 (4) ◽  
pp. 1844
Author(s):  
Guilherme Giesel ◽  
Martha Andreia Brand ◽  
Flaviana Reis Milagres ◽  
Renato Augusto Pereira Damasio

In pulp production, wood in logs is stored for periods that can range from a few weeks to several months. During storage, changes in the wood properties that affect the pulping process and the quality of the pulp may occur. The objective of this study was to determine the ideal timing of wood storage in logs by evaluating the variations (a) in the chemical properties of wood (b) in the parameters of the pulping process and (c) the quality of the Pinus taeda pulp. Logs were stored in an industrial courtyard for 30, 60, 90, 120 and 150 days. In each storage period, the physical and chemical properties of the wood, the cooking parameters, and the properties of the pulp were analyzed. The chemical properties of wood varied throughout storage, but only the solubility in sodium hydroxide showed a positive and significant correlation with storage time. In pulping, the yield and tailings had an inversely proportional correlation with the storage time, while the organic and total solids content had a positive correlation. As for cellulose quality, arabinan and soluble lignin contents did not vary during storage. The mannan content had a positive and significant correlation with the storage time. Taking into account all the variables analyzed, the storage time of P. taeda logs should be up to 30 days.


1999 ◽  
Vol 23 (4) ◽  
pp. 197-202 ◽  
Author(s):  
Timothy B. Harrington ◽  
Jason A. Gatch ◽  
Terry S. Price

Abstract Twenty-four machine-planted stands of loblolly pine (Pinus taeda L.) of ages 3 to 10 yr were sampled near Athens, GA, to compare stem sinuosity, tree size, and pest injury of trees with bent versus straight taproots. Based on a 0- to 8-point index, the average level of stem sinuosity was medium (X = 2.6; n = 1,327 trees). Trees of high or low stem sinuosity index were identified near each of ten points per site, and one was selected to best represent each level (n = 240 pairs). Seventy-two pairs were excavated, and of these, 62 and 82 trees had bent and straight taproots, respectively. Levels of stem sinuosity were medium or high for 77% of trees with bent taproots, while they were low for 71% of trees with straight taproots (chi-square P = 0.001). Trees with bent taproots were 7% to 9% smaller in stem diameter and height, while their stem sinuosity index was over twice that of trees with straight taproots (P = 0.01). Taproot azimuth did not differ significantly (P > 0.20) from planting row azimuth, indicating that bent taproots from machine planting remained confined to the planting slit. Although biological mechanisms were not identified, results indicate a potentially problematic association between bent taproots and reduced stem quality of loblolly pine. South. J. Appl. For. 23(4):197-202.


2004 ◽  
Vol 62 (3) ◽  
pp. 221-224 ◽  
Author(s):  
E. Y. A. Okino ◽  
D. E. Teixeira ◽  
M. R. de Souza ◽  
M. A. E. Santana ◽  
M. E. de Sousa

2020 ◽  
Vol 19 (2) ◽  
pp. 112-116
Author(s):  
Luana Maria dos Santos ◽  
Erick Martins Nieri ◽  
Flávia Alves Pereira ◽  
Sandra Mara Krefta ◽  
Jéssica Batista da Mata

The companies in the forestry sector seek highly durable wood, prioritizing the use of planted forests, and the thermal treatment is a viable alternative to provide quality to these woods. Thus, the objective of the study was to evaluate the resistance of the heat-treated Pinus taeda L wood by the attack of white rot fungus Trametes versicolor (L.) CG Lloyd. The P. taeda L. wood was deployed in joinery to obtain samples with dimensions of 30 x 15 x 2.5 cm (length x width x thickness), being treated at temperatures of 140, 160 and 180ºC. From these, 1.0 x 1.0 x 1.0 cm specimens were obtained and subjected to the fungus for six weeks. The accelerated rot test was carried out in accordance with the ASTM D2017 standard. The experiment was conducted in a completely randomized design with four treatments (T1 = 0; T2 = 140°C; T3 = 160°C and T4 = 180°C) and nine replications. The loss of mass caused by the fungus was less in heat treated wood. On the other hand, the increase in temperature did not provide greater resistance to the material. In conclusion, heat treatment has reduced the degradation caused by the white rot fungus Trametes versicolor. Heat treatment at 140°C is indicated to avoid loss of mass in P. taeda L. woods submitted to the fungus T. versicolor. All treated woods were classified as highly resistant.


1989 ◽  
Vol 13 (3) ◽  
pp. 127-132 ◽  
Author(s):  
L. John Frampton ◽  
James F. Hodges

Abstract Methods used to root slash (Pinus elliottii var. elliottii Englem.) and loblolly (Pinus taeda L.) pine cuttings from 1-0 seedlings in outdoor nursery beds are described. The species, the date of setting (February or March) and the type of shoot collected (succulent, top-pruned or bud-set)influenced rooting success. A February rather than March setting date is recommended. The succulent shoot type rooted best for slash pine while nonsucculent shoot types rooted best for loblolly pine. When considering all types of shoots set in February, slash and loblolly pine cuttings rootedat 77 and 69%, respectively. After lifting, approximately 70% of the cuttings that rooted (or 52% of all cuttings set in February) were judged acceptable for planting. Current costs of producing rooted cuttings exceed that of barefoot seedlings. However, as technology is developed to rootcuttings on a larger scale in the nursery, the superior genetic quality of plantations derived from rooted cuttings may offset their extra cost, relative to seedlings, enough to economically justify their operational use. If so, these procedures will offer forest managers an additional andmore effective option than seedling propagation for exploiting genetic variation in order to enhance forest productivity. South. Appl. For. 13(3):127-132.


FLORESTA ◽  
2013 ◽  
Vol 44 (1) ◽  
pp. 53 ◽  
Author(s):  
Eduardo Silva Lopes ◽  
Diego De Oliveira ◽  
Jean Alberto Sampietro

AbstractThe objective of this study was to evaluate the influence of different wheel types of a skidder on productivity and cost of Pinus taeda L. wood extraction. The study was conducted in a forestry company located in the municipality of Mandirituba, Paraná state, Brazil. The technical and cost analyses included a time and motion study of the wood extraction activity. The productivity, operative efficiency, energy consumption and the production and operational costs were determined for the machines with different wheel types: SDP - skidder with rubber tires; SD2 – skidder with tracks on the two front tires; and SD4 – skidder with tracks on the four tires. Results showed that the activity that demanded most time in the operational cycle was the maneuvering of the machines to pick up more than one tree, resulting in lost of productivity and need of improvement in the operational planning. The skidder equipped only with rubber tires showed higher productivity and lower production cost in the longest extraction distances, caused by the higher operating speed of the machine.Keywords: Timber extraction; wheel types; operating efficiency. ResumoInfluência dos rodados de um skidder na produtividade e no custo da extração florestal. Este trabalho objetivou avaliar a influência de diferentes tipos de rodados de um skidder na produtividade e no custo da extração de madeira de Pinus taeda L. O estudo foi conduzido em uma empresa florestal localizada no município de Mandirituba, estado do Paraná, Brasil. As análises técnica e de custo englobaram um estudo de tempos e movimentos da operação de extração florestal. Foi determinado a produtividade, eficiência operacional, rendimento energético e custos operacionais e de produção das máquinas equipadas com diferentes tipos de rodados: SDP – skidder com rodados de pneus; SD2 – skidder com pneus dianteiros recobertos com semiesteiras e SD4 – skidder com os quatro pneus recobertos com semiesteiras. Os resultados mostraram que a atividade que demandou o maior tempo do ciclo operacional foram as manobras realizadas pelas máquinas para apanhar mais de uma árvore, ocasionando perda de produtividade e necessidade de melhoria no planejamento operacional. O skidder equipado somente com rodados de pneus apresentou maior produtividade e menor custo de produção nas maiores distâncias de extração, ocasionado pela maior velocidade operacional da máquina.Palavras-chave: Extração florestal; tipos de rodados; eficiência operacional.


2021 ◽  
Vol 51 ◽  
Author(s):  
Natali De Oliveira Pitz ◽  
Jean Alberto Sampietro ◽  
Erasmo Luis Tonett ◽  
Luis Henrique Ferrari ◽  
Philipe Ricardo Casemiro Soares ◽  
...  

Background: Work studies are fundamental for the development and assessment of timber harvesting systems aimed at rationalising and improving forest management activities.   Methods: This study evaluated the operational performance of a mechanised whole-tree harvesting system in 32-year-old Pinus taeda L. stands producing multiple timber products. A time and motion study at the cycle element level was conducted to evaluate the operational performance of each component of the harvesting system. Equations were developed to estimate the productivity of tree extraction activity with a wheeled skidder and log loading with a mechanical loader. Results: Tree felling with an excavator-based harvester had the highest mean productivity (135 m3 per productive machine hour), followed by tree extraction with a wheeled skidder (117 m3 per productive machine hour), while manually processing larger logs with a chainsaw had the lowest productivity (25.7 m3 per productive machine hour). Operator, extraction distance and mean log volume had a significant effect on the performance of different activities and were included in productivity models. Conclusions: Operational performance of equipment was variable and dependent on the effect of the operator, extraction distance and log volume. Thus, the use of models to estimate productivity considering such factors, coupled with reduced delays to increase utilisation of equipment, will contribute to the better management and planning of forest harvesting operations under the evaluated conditions.


2013 ◽  
Vol 70 (4) ◽  
pp. 429-437 ◽  
Author(s):  
Mário Dobner JR. ◽  
Leif Nutto ◽  
Antonio R. Higa

1993 ◽  
Vol 17 (2) ◽  
pp. 80-83 ◽  
Author(s):  
J. P. Barnett ◽  
J. M. McGilvray

Abstract The performance of container and bareroot loblolly pine (Pinus taeda L.) seedlings from the same improved seedlot was compared on highly productive bottomland sites in South Carolina. At the time of planting, size and quality of the open-grown container stock were equal to or betterthan bareroot material. When outplanting conditions were ideal, field plantings in March, April, and May of 2 successive years indicated equal performance of the 2 stock types. When conditions were more stressful, container stock survived and grew better than bareroot seedlings. Needle-tipburn caused by postplanting applications of herbicides had no long-term effects on seedling growth. South. J. Appl. For. 17(2):80-83.


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