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Published By Scielo

0100-6762, 0100-6762

2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Fillipe Tamiozzo Pereira Torres ◽  
Rafael Gomes Siqueira ◽  
Gilberto Fialho Moreira ◽  
Gumercindo Souza Lima ◽  
Sebastião Venâncio Martins ◽  
...  

ABSTRACT The aim of this study is to analyze the factors that affect the occurrence of fires in the vegetation, in the area of the Serra do Brigadeiro State Park (PESB) and its surroundings, and through this information to establish the most appropriate methodology to generate a risk map for fires in the place. A risk cartogram for fires was developed with the help of the ArcGIS 10.1 software, by the generation of maps of slope, aspects and land use. These maps were intercrossed, enabling the determination of the areas most susceptible to fires. Tested methodologies varied in the form of assigning grades to each predictor class of fire as well as in the division of risk classes. According to the results, the assignment of notes to each predictor class, depending on the size of the burned area and taking into account the history of events, reflected the risk of fires in vegetation in the region more satisfactorily.


2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Carlos Miguel Simões da Silva ◽  
Benedito Rocha Vital ◽  
Angélica de Cassia Oliveira Carneiro ◽  
Aylson Costa Oliveira ◽  
Solange Oliveira Araújo ◽  
...  

ABSTRACT The objective of this study was to evaluate the effect of the final torrefaction temperature on the energy properties of wood. It was applied four treatments with three replicates, consisting of untreated wood particles and particles torrefied at temperatures of 170, 220 and 260ºC. Better physical, chemical and thermal properties of the particles were observed as a function of the torrefaction temperature. Comparing with the control group, the particles torrefied at the highest final temperature (260ºC) showed significant differences in bulk density - from 239 to 396kg/m3; the equilibrium moisture content changed from 12.3 to 5.7%; fixed carbon content - from 13.0 to 24.8%; heating value - from 4,465 to 4,945kcal/kg; and energy density - from 882 to 1,727Mcal/m3. It was concluded that torrefaction had a positive effect on the energy properties of the wood.


2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Victor de Freitas Neubert ◽  
Aloísio Xavier ◽  
Haroldo Nogueira de Paiva ◽  
Poliana Coqueiro Dias ◽  
Ricardo Gallo

ABSTRACT The objective of this work was to evaluate the production and survival of the mini-stumps in mini-clonal hedge and the effect of leaf reduction of mini-cuttings on rooting and seedling growth of progenies of Vinhático (Plathymenia foliolosa) by mini-cutting. Apical mini-cuttings were used to evaluate the influence of leaf reduction on the rooting of vinhático; the mini-cuttings ranged between 8 to 10 cm in length and samples were subjected to100% leaf reduction (without leaf), 75% of leaf reduction, or no leaf reduction. As for the survival of mini-stumps in mini-clonal hedge, after the fourth successive mini-cuttings collection, P3 and P19 progenies showed the highest survival percentages (64.5% and 61.5%, respectively), while progenies P1 (32.3 %) and P45 (25%) showed the lowest values for this parameter. The average number of mini-cuttings/mini-stump/collection produced ranged from 0.83 (progeny 53) to 4.8 (progeny 01) and the average productivity was 120 m2 mini-stumps/mini-cuttings per collection. These results suggest that leaf reduction in adventitious rooting in mini-cuttings did not result in any difference between foliar treatments without reduction and 75% leaf reduction; however, 100% mortality was observed when the mini-cuttings were made with total leaf reduction.The progenies studied showed potential regeneration of mini-stumps, thus allowing the realization of successive collections of young shoots.


2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Juliana Cristina da Silva ◽  
Ana Márcia Macedo Ladeira Carvalho ◽  
Bruno de Freitas Homem de Faria

ABSTRACT There are many species of the Eucalyptus genus presents high levels of the growth stress. These stresses are mechanical efforts generated during the tree growth to help maintaining the balance of the cup in response to environmental and silvicultural agents. The stresses are responsible for the cracks of tops and for the warp after unfolding. The objective of this study was to test five different methods to minimize the effects of growth stress on the production of Eucalyptus urophylla sawlogs. The boards produced were then evaluated and measured for cracking, arching, curvature and cupping. The treatment with herbicide presented the smallest medium indexes of cracking (16.63 cm) and of arching (0.23 mm.m-1), while the medium curvature was smaller than observed in boards unfolded in 72 hours after the reduction of the trees (0.88 mm.m-1). Unfolding after ten days of harvesting represented the less efficient technique in the cracking control, curvature and arching. The cupping was not observed during boards processing. The herbicide application was more efficient in the reduction of the effects of the growth tensions.


2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Felipe Leitão da Cunha Marzano ◽  
Amaury Paulo de Souza ◽  
Luciano José Minette

ABSTRACT Context: In mechanized forestry work, the ergonomic conditions of the workplace affects operator's health, performance and productivity. Originality: A comparison of different forest machines becomes complex in case where it is required analysis of several ergonomic factors simultaneously. There are several methods of ergonomic analysis however, a more complete methodology that considers several ergonomic factors and produces an index that represent the ergonomic condition of the machine is needed. Objective: Propose a methodology to determining an Ergonomic Conformity Index to evaluate Harvesters and Forwarders of different brands. Methodology: The ECI was determined initially basing in four relevant ergonomic factors: noise, vibration, thermal environment and air quality. These factors were evaluated utilizing four Harvesters and two Forwarders in eucalyptus timber harvesting operations. For each factor, a score was given according to its compliance with the established parameters. The ECI was obtained from an average of the scores given to each factor. The index ranges from zero to one, so that lower values indicate worse ergonomic conditions. Results: All the analyzed machines had continuous noise between 75.0 and 82.6 dB (A) and whole-body vibration between 0.27 and 0.70 m s-2. HV1 and HV2 presented thermal environment in accordance with the established criteria, other machines showed deficiencies in this regard. All the machines presented non-conformities in the air quality, except HV2. The ECI of Harvesters HV1, HV2, HV3 and HV4, were 0.83; 0.88; 0.71; 0.63. The ECI of Forwarders FW1 and FW2 were 0.58 and 0.79. Conclusion: The determination of the ECI allowed an evaluation and comparison between analyzed forest machines. The machine with the higher ECI had only one non-conformity, and it was related to noise inside the cab. The machine that got the lower ECI presented non-conformities for all the factors.


2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Victor de Freitas Neubert ◽  
Aloísio Xavier ◽  
Haroldo Nogueira de Paiva ◽  
Poliana Coqueiro Dias ◽  
Ricardo Gallo

ABSTRACT The objective of this work was to evaluate the production and survival of the mini-stumps in mini-clonal hedge and the effect of leaf reduction of mini-cuttings on rooting and seedling growth of progenies of Vinhático (Plathymenia foliolosa) by mini-cutting. Apical mini-cuttings were used to evaluate the influence of leaf reduction on the rooting of vinhático; the mini-cuttings ranged between 8 to 10 cm in length and samples were subjected to100% leaf reduction (without leaf), 75% of leaf reduction, or no leaf reduction. As for the survival of mini-stumps in mini-clonal hedge, after the fourth successive mini-cuttings collection, P3 and P19 progenies showed the highest survival percentages (64.5% and 61.5%, respectively), while progenies P1 (32.3 %) and P45 (25%) showed the lowest values for this parameter. The average number of mini-cuttings/mini-stump/collection produced ranged from 0.83 (progeny 53) to 4.8 (progeny 01) and the average productivity was 120 m2 mini-stumps/mini-cuttings per collection. These results suggest that leaf reduction in adventitious rooting in mini-cuttings did not result in any difference between foliar treatments without reduction and 75% leaf reduction; however, 100% mortality was observed when the mini-cuttings were made with total leaf reduction.The progenies studied showed potential regeneration of mini-stumps, thus allowing the realization of successive collections of young shoots.


2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Carlos Miguel Simões da Silva ◽  
Benedito Rocha Vital ◽  
Angélica de Cassia Oliveira Carneiro ◽  
Aylson Costa Oliveira ◽  
Solange Oliveira Araújo ◽  
...  

ABSTRACT The objective of this study was to evaluate the effect of the final torrefaction temperature on the energy properties of wood. It was applied four treatments with three replicates, consisting of untreated wood particles and particles torrefied at temperatures of 170, 220 and 260ºC. Better physical, chemical and thermal properties of the particles were observed as a function of the torrefaction temperature. Comparing with the control group, the particles torrefied at the highest final temperature (260ºC) showed significant differences in bulk density - from 239 to 396kg/m3; the equilibrium moisture content changed from 12.3 to 5.7%; fixed carbon content - from 13.0 to 24.8%; heating value - from 4,465 to 4,945kcal/kg; and energy density - from 882 to 1,727Mcal/m3. It was concluded that torrefaction had a positive effect on the energy properties of the wood.


2017 ◽  
Vol 41 (1) ◽  
Author(s):  
Ivar Wendling ◽  
Carlos André Stuepp ◽  
Delmar Santin ◽  
Katia Christiana Zuffellato-Ribas

ABSTRACT Araucaria angustifolia (Brazilian Pine or Araucaria) is a potential native species to Brazilian forestry. However, a number of challenges and technical restraints still persist, making difficult its expansion as a species for forest plantations, among which the lack of cloning technologies evaluation in field conditions. So the present study aimed to evaluate the potential use of Araucaria plants produced by cuttings and grafting for wood production in comparison to those produced by seeds, by assessing field vigor and establishing a form factor for plantations with equivalent age. Plants from cuttings and seeds were planted in a 3 x 3 m spacing, being part of the last intended to be rootstocks for grafting. The experiment was conducted in a completely randomized design with three treatments and plots of a plant (one tree plot). Plants from cuttings had higher growth in diameter at breast height (7.4 ± 2.41 cm) and total height (4.2 ± 1.08 m) at 74 months after planting, followed by grafted plants and from seeds, with similar results. We conclude that cuttings and grafting are potential techniques for Araucaria plants formation for wood production, and, in particular, grafting is recommended by the easiness of in its application, besides the fact that it can be used for seed orchards formation and presents volumetric increase and form factor similar to seedlings.


2017 ◽  
Vol 41 (4) ◽  
Author(s):  
Juliana Cristina da Silva ◽  
Ana Márcia Macedo Ladeira Carvalho ◽  
Bruno de Freitas Homem de Faria

ABSTRACT There are many species of the Eucalyptus genus presents high levels of the growth stress. These stresses are mechanical efforts generated during the tree growth to help maintaining the balance of the cup in response to environmental and silvicultural agents. The stresses are responsible for the cracks of tops and for the warp after unfolding. The objective of this study was to test five different methods to minimize the effects of growth stress on the production of Eucalyptus urophylla sawlogs. The boards produced were then evaluated and measured for cracking, arching, curvature and cupping. The treatment with herbicide presented the smallest medium indexes of cracking (16.63 cm) and of arching (0.23 mm.m-1), while the medium curvature was smaller than observed in boards unfolded in 72 hours after the reduction of the trees (0.88 mm.m-1). Unfolding after ten days of harvesting represented the less efficient technique in the cracking control, curvature and arching. The cupping was not observed during boards processing. The herbicide application was more efficient in the reduction of the effects of the growth tensions.


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