scholarly journals HAND-ARM VIBRATION IN DIFFERENT OPERATING CONDITIONS WITH A CHAINSAW

FLORESTA ◽  
2022 ◽  
Vol 52 (1) ◽  
pp. 074
Author(s):  
Juliano Dos Santos Depoi ◽  
Catize Brandelero ◽  
Valmir Werner ◽  
José Fernando Schlosser ◽  
Alexandre Russini ◽  
...  
Keyword(s):  
Eucalyptus Grandis ◽  
Forest Harvesting ◽  
Operating Conditions ◽  
Forest Species ◽  
Technological Advances ◽  
Regulatory Standards ◽  
Forestry Sector ◽  
Eucalyptus Dunnii ◽  
Reference Limits ◽  
Iso 2631

The mechanization of forest harvesting is a trend in Brazil. However, small and medium-sized companies in the forestry sector, even today, opt for semi-mechanized harvesting, using chainsaws for the harvesting and sectioning of trees. Despite technological advances, when operated continuously, chainsaws may cause damage to the operator’s body, acting as a stressor, and vibration excess is responsible for numerous health disorders, among them the Raynaud syndrome. In this sense, this study aimed to determine the vibration levels to which a chainsaw operator is subjected, during the transversal cut (tracing) of the wood, in different forest species and cutting sets. The treatments consisted of three forest species (Eucalyptus grandis, Eucalyptus dunnii and Acacia mearnsii De Wild) and two cutting sets, consisting of square tooth chains of the semi-chisel and chisel types. The vibration assessment was based on the criteria established by the Regulatory Standards NR15, NHO10 and ISO 2631-4. The results of vibration levels were higher than the reference limits established by ISO 2631-4, and, for both cutting sets, the highest vibration levels occurred on the “x” axis. After the data processing, the acceleration values resulting from the normalized exposure to hand-arm vibrations showed significant differences for the “y” and “z” axes. Therefore, it can be inferred that the chainsaw operation is a stressor, potentially capable of causing damage to workers' health. 

scholarly journals Comparative Dynamics of Above-Ground Litter Production and Decomposition from Eucalyptus Grandis Hill ex Maiden and Pinus Taeda L., and Their Contribution to Soil Organic Carbon

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 349
Author(s):  
Andrés Baietto ◽  
Jorge Hernández ◽  
Amabelia del Pino
Keyword(s):  
Pinus Taeda ◽  
Decomposition Rate ◽  
Methodological Approach ◽  
Eucalyptus Grandis ◽  
Isotopic Analysis ◽  
Forest Litter ◽  
First Year ◽  
Litter Production ◽  
Forest Species ◽  
Pinus Taeda L

The replacement of native pasture by exotic commercial forest species is an infrequent situation worldwide. In these systems, a new component is introduced, forest litter, which constitutes one of the main ways of incorporating carbon into the soil–plant system. The present work seeks to establish a methodological approach to study the dynamics of litter production and decomposition in an integrated way. The general objective was to characterize and compare the litter production dynamics in 14-year-old Eucalyptus grandis Hill ex Maiden and Pinus taeda L. commercial plantations. During two years, seasonal evaluations of fall, decomposition and accumulation of litter were carried out in stands of both species. In turn, the contribution of carbon from forest species to the soil through isotopic analysis techniques was quantified. Litterfall in E. grandis showed maximums during the spring of the first year and in the spring and summer of the second. In P. taeda, the maximums occurred in summer of the first year and in autumn of the second. In relation to the decomposition rate, the results based on short periods of evaluation between 15 and 21 months did not show differences between species, nor for the different moments of beginning of the evaluation, obtaining average values of 0.0369 month−1 for E. grandis and 0.0357 month−1 for P. taeda. In turn, both the decomposition rate of the material as a whole and the estimates of accumulated biomass in equilibrium state did not show significant differences between the species. Additionally, there was a relevant incorporation of carbon into the soil by forest species, fundamentally in the first few centimeters, substituting an important proportion of the carbon inherited by the original cover of native pastures. Finally, it is necessary to specify that the scope of the findings obtained is greatly limited by the sample size used in this study.

scholarly journals Theoretical Overview of Successional Considerations in Vegetation Management

1990 ◽  
Vol 66 (4) ◽  
pp. 361-365 ◽  
Author(s):  
E. T. Oswald
Keyword(s):  
Forest Succession ◽  
Forest Tree ◽  
Vegetation Management ◽  
Forest Harvesting ◽  
Burning Time ◽  
Forest Species ◽  
Forest Sites ◽  
Site Characteristics ◽  
Chemical Techniques ◽  
Theoretical Overview

Forest succession most relevant to forestry originates following forest harvesting or wildfire. That following harvesting is most often also influenced by site preparation procedures for reforestation. The resultant vegetation succession is dependent on the type, degree, and timing of the disturbance, the site characteristics and conditions, and the microclimate. Subsurface organs, including roots, rhizomes, and stumps, allow most species of shrubs occurring on moist and wet forest sites to survive burning and crushing. Establishment and survival of some forbs, such as fireweed and bracken fern, are greatly facilitated by burning. Effective non-chemical techniques for providing desirable forest tree species a successional advantage over competing forest species are discussed. These involve different silvicultural systems, time of logging, type of scarification, time and degree of burning, time of planting, size of seedlings, and other reforestation considerations.

scholarly journals Painéis Compensados Fabricados com Lâminas de Três Espécies de Eucaliptos

2017 ◽  
Vol 24 (0) ◽  
Author(s):  
Sandra Kazmierczak ◽  
Everton Hillig ◽  
Setsuo Iwakiri
Keyword(s):  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla ◽  
Eucalyptus Saligna ◽  
Eucalyptus Dunnii ◽  
E 32

RESUMO O objetivo foi analisar a qualidade de painéis compensados produzidos com lâminas de Eucalyptus saligna, Eucalyptus dunnii e o híbrido Eucalyptus urophylla x Eucalyptus grandis, em diferentes composições de misturas. Foram produzidos painéis com 500 × 500 × 14 mm e sete camadas de lâminas, coladas com fenol-formaldeído (FF), na gramatura de 360 g. m-2 em linha dupla e teores de sólidos de 28% e 32%. A prensagem dos painéis foi realizada a 130 °C, 12 kgf. cm-2 e 15 minutos. Analisaram-se as propriedades massa específica, umidade, absorção d’água, inchamento em espessura, cisalhamento na linha de cola e flexão estática. Os resultados foram comparados aos requisitos do catálogo técnico da ABIMCI e das normas EN 314-2 e DIN 68792. Os painéis de Eucalyptus dunnii apresentaram menores valores de propriedades mecânicas, com tendência de aumento quando em misturas. Os painéis de Eucalyptus saligna e do híbrido Eucalyptus urophylla x Eucalyptus grandis apresentaram bons resultados, tanto puros como em mistura com as outras espécies.

scholarly journals INTEMPERISMO ARTIFICIAL DE QUATRO REVESTIMENTOS APLICADOS EM MADEIRAS DE DUAS ESPÉCIES FLORESTAIS

Nativa ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 313 ◽  
Author(s):  
Aline Krolow Soares ◽  
Roberto Lessa Pereira ◽  
Pedro Henrique Gonzalez de Cademartori ◽  
Henrique Weber Dalla Costa ◽  
Darci Alberto Gatto
Keyword(s):  
Morphological Changes ◽  
Eucalyptus Grandis ◽  
Accelerated Aging ◽  
Surface Wettability ◽  
Forest Species ◽  
Artificial Weathering ◽  
Color Changes ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Weathering Resistance

O presente estudo teve como objetivo investigar a resistência ao intemperismo artificial de quatro revestimentos aplicados nas madeiras de duas espécies florestais. Para tal, foram utilizadas seis árvores de Eucalyptus grandis e três árvores de Tetrorchidium rubrivenium as quais foram desdobradas para confecção de 50 amostras para cada espécie, com dimensões de 5,0x7,0x1,0cm (largura, comprimento e espessura, respectivamente). A superfície das madeiras foi revestida com quatro acabamentos: polistein, verniz marítimo, tinta branca base óleo e tinta branca base água. As amostras sem revestimento e revestidas foram submetidas ao ensaio de envelhecimento acelerado durante 480 horas. A resistência ao intemperismo artificial foi avaliada por meio das modificações colorimétricas e morfológicas ao longo da exposição das madeiras e em função da molhabilidade superficial. Os principais resultados mostraram que a superfície das madeiras  tendeu a tons opacos após exposição de 480 horas. Foi observado que os revestimentos não evitaram o aumento da molhabilidade superficial. Após todo o período de exposição, as madeiras não apresentaram modificações morfológicas tais como rachaduras e descascamento dos revestimentos, o que denota importante característica de proteção à madeira.Palavras-chave: Eucalyptus, canemaçu, modificação da superfície, envelhecimento acelerado, durabilidade da madeira. ARTIFICIAL WEATHERING OF FOUR COATINGS APPLIED ON WOODS OF TWO FOREST SPECIES ABSTRACT:The present study aimed to investigate the resistance to artificial weathering of four coatings applied on wood from two forest species. Six trees of Eucalyptus grandis and three trees of Tetrorchidium rubrivenium were cut to produce 50 wood samples for each species with dimensions of 5.0x7.0x1.0 cm (width, length and thickness, respectively). Wood surface was coated with four finishing products: polistein, marine varnish, oil-based white paint and water-based white paint. The uncoated and coated wood samples were subjected to accelerated aging test for 480h. The artificial weathering resistance was evaluated by color changes and surface wettability. The main results showed the coated woods tend to opaque tones after the exposure for 480h. The coatings did not avoid the increase of the surface wettability. After the exposure, both woods did not present morphological changes, such as cracks and peeling into the coatings, which represent relevant characteristics for wood protection.Keywords: Eucalyptus, canemaçu, surface modification, accelerated aging, wood durability. DOI:

scholarly journals Comparing Hot and Cold Loading in an Integrated Biomass Recovery Operation

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 385
Author(s):  
Anil Raj Kizha ◽  
Han-Sup Han ◽  
Nathaniel Anderson ◽  
Anil Koirala ◽  
Libin T. Louis
Keyword(s):  
Forest Harvesting ◽  
Primary Objective ◽  
Operating Conditions ◽  
Sampling Techniques ◽  
Loading Capacity ◽  
Work Sampling ◽  
Operational Characteristics ◽  
Truck Loading ◽  
Biomass Components ◽  
The Cost

The balance of production activities at the landing is pivotal to the success of any forest harvesting operation and has a direct impact on the cost and efficiency of the enterprise. The primary objective of this study was to understand the operational characteristics of the loader in a hot operation (handling both sawlog and biomass components concurrently) and cold operation (handling biomass and sawlogs separately) for harvesting sawlogs and biomass. Systematic work sampling techniques were employed to obtain “snapshots” of the loader activities for a cable logging operation, including the interaction of the loader with other operational phases and delay time for both hot and cold configurations. The results show that for hot loading at the landing, the yarder was the most utilized machine (85%), and was the bottleneck of the operation, followed by the loader (70%). In the hot loading configuration, 39% of operational delay during truck loading was caused by the loader and was predominantly due to movement of the loader within or between the landings. This was followed by the yarder (19%, due to rigging activities) and the chaser (15%, to maintain the crews’ safety). In the cold loading configuration, delays due to the unavailability of roll-off bins constituted up to 77% of the operational delay. This suggests that the number of bins and trucks hauling biomass has a crucial role in the overall efficiency of the biomass harvesting system, and should be well balanced with loading capacity. Additionally, the choice of hot or cold biomass loading operations is highly dependent on the site and operating conditions.

scholarly journals Optimization of the micropropagation of elite adult trees of Sequoia sempervirens: forest species of interest in the Basque Country, Spain

Bionatura ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 1511-1519
Author(s):  
Alejandra Rojas Vargas ◽  
A Castander-Olarieta ◽  
P Moncaleán ◽  
I.A Montalbán
Keyword(s):  
Climate Change ◽  
Acetic Acid ◽  
Butyric Acid ◽  
Pinus Radiata ◽  
Basque Country ◽  
Sequoia Sempervirens ◽  
Naphthalene Acetic Acid ◽  
Root Induction ◽  
Forest Species ◽  
Forestry Sector

Forest trees are renewable sources of timber and other valuable non-timber products. Nowadays, the increase in population and demand for forestry products results in overexploitation of forestry. Therefore, there is an urgent need to produce elite plants with higher productivity under stress derived from climate change to have available to afforestation. For this reason, propagation methods should be improved to be more efficient in terms of quality and productivity. The main species planted in the Basque Country is Pinus radiata; during the last three years, Pinus radiata plantations have suffered a fungus attack affecting mainly needles until the tree's death. This crisis is caused by the combined action of two fungi of the genus Dothistroma and Lecanosticta acicola, whose expansion seems to have been enhanced by weather-related factors, such as humid and hot summers. Although we have evidence of this disease's presence in our mountains since 1942, the disease has had a speedy expansion with an aggressive effect for reasons that are not scientifically known today. For the above, Basque Country forestry sector is looking for alternative species to be used in its plantations. Part of the forestry sector considers that Sequoia sempervirens could be a good choice for plantations. Besides, its high-quality wood and its tolerance to the attack of several pathogens and other diseases derived from climate change are characteristics that could confer some advantage over other forest species. The main goal of this study was to optimize the micropropagation of adult elite trees of Sequoia sempervirens. The effect of 6-benzylaminopurine, meta-Topolin and Kinetin, and 4 types of explant in the multiplication stage were analyzed to carry out this objective. Furthermore, the effect of two types of auxins: 1-naphthalene acetic acid, indole-3-butyric acid, and a mixture of both, were evaluated on the induction of roots and their subsequent effect on the acclimatization process. The best multiplication index was obtained when 4.4 µM 6-benzylaminopurine and apical explants longer than 1.5 cm of length were used. The root induction percentage was 75% in the most responsive genotype analyzed when 4.4 µM 6-benzylaminopurine was used on the induction stage, and 50 µM of 1-naphthalene acetic acid was used for rooting. Finally, after 3 months in the greenhouse, the explants cultured with Kinetin and rooted in a culture medium with indole-3-butyric acid showed the highest acclimatization success (94%).

Zoning Based on Climate and Soil for Planting Eucalyptus in Southern Region of Rio Grande do Sul State, Brazil

2011 ◽  
pp. 127-143
Author(s):  
José Alba ◽  
Marcos Wrege ◽  
Marilice Garrastazu
Keyword(s):  
Sustainable Use ◽  
Eucalyptus Grandis ◽  
Rio Grande ◽  
Southern Region ◽  
Temperate Climate ◽  
Eucalyptus Species ◽  
Rio Grande Do Sul ◽  
Eucalyptus Dunnii ◽  
Legal Restrictions ◽  
Positive Step

Zoning based on climate and soil characteristics does not represent a full ecological-economic zoning procedure, as the Brazilian law establishes, but it is a positive step forward toward a sustainable use of natural resources. The Embrapa Temperate Climate Research Center has developed, with the collaboration of several entities from Brazil and Uruguay, a zoning procedure based on climate and soil for planting eucalyptus in southern region of Rio Grande do Sul State covering a total area greater than 3,5 million hectares. Three eucalyptus species were considered: Eucalyptus grandis W. Hill ex Maiden, Eucalyptus dunnii Maiden and Eucalyptus globulus Labill. Data were processed and integrated through statistical procedures and by using a GIS. The potential surface area for forestry surpasses 900,000 hectares, but a homogeneous exploitation of that territory is limited by legal restrictions.

scholarly journals PRODUÇÃO DE PAINEL COMPENSADO ESTRUTURAL DE Eucalyptus grandis E Eucalyptus dunnii

FLORESTA ◽  
2007 ◽  
Vol 37 (3) ◽  
Author(s):  
Setsuo Iwakiri ◽  
Sidon Keinert Júnior ◽  
José Guilhrme Prata ◽  
Silviana Rosso
Keyword(s):  
Eucalyptus Grandis ◽  
Eucalyptus Dunnii

Este trabalho foi desenvolvido com o objetivo de avaliar o potencial de utilização de lâminas de Eucalyptus grandis e Eucalyptus dunnii para produção de painéis compensados estruturais. Os painéis foram produzidos com diferentes formulações de adesivo à base de resina fenol-formaldeído. Os resultados indicaram que as diferentes formulações do adesivo não afetam de forma clara a resistência da linha de cola. Entre as espécies, os painéis de E. grandis apresentaram maiores valores de resistência da linha de cola em comparação aos painéis de E. dunnii. Os valores médios de MOR das duas espécies foram estatisticamente iguais. Os resultados das propriedades mecânicas avaliadas apontam que o E. grandis e E. dunnii são espécies com grande potencial para produção de painéis compensados estruturais.

Influence of age and planting density on the energy content of Eucalyptus benthamii, Eucalyptus dunnii and Eucalyptus grandis planted in Uruguay

New Forests ◽  
2019 ◽  
Vol 51 (4) ◽  
pp. 631-655
Author(s):  
Fernando Resquin ◽  
Rafael M. Navarro-Cerrillo ◽  
Leónidas Carrasco-Letelier ◽  
Cecilia Rachid-Casnati
Keyword(s):  
Energy Content ◽  
Eucalyptus Grandis ◽  
Planting Density ◽  
Eucalyptus Dunnii

scholarly journals Variability and Plasticity in Cuticular Transpiration and Leaf Permeability Allow Differentiation of Eucalyptus Clones at an Early Age

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 9 ◽  
Author(s):  
André Carignato ◽  
Javier Vázquez-Piqué ◽  
Raúl Tapias ◽  
Federico Ruiz ◽  
Manuel Fernández
Keyword(s):  
Water Stress ◽  
Drought Resistance ◽  
Stomatal Density ◽  
Stomatal Closure ◽  
Eucalyptus Grandis ◽  
Leaf Traits ◽  
Improvement Program ◽  
Stomatal Control ◽  
Cuticular Transpiration ◽  
Eucalyptus Dunnii

Background and Objectives. Water stress is a major constraining factor of Eucalyptus plantations’ growth. Within a genetic improvement program, the selection of genotypes that improve drought resistance would help to improve productivity and to expand plantations. Leaf characteristics, among others, are important factors to consider when evaluating drought resistance evaluation, as well as the clone’s ability to modify leaf properties (e.g., stomatal density (d) and size, relative water content at the time of stomatal closure (RWCc), cuticular transpiration (Ec), specific leaf area (SLA)) according to growing conditions. Therefore, this study aimed at analyzing these properties in nursery plants of nine high-productivity Eucalyptus clones. Material and Methods: Five Eucalyptus globulus Labill. clones and four hybrids clones (Eucalyptus urophylla S.T. Blake × Eucalyptus grandis W. Hill ex Maiden, 12€; Eucalyptus urograndis × E. globulus, HE; Eucalyptus dunnii Maiden–E. grandis × E. globulus, HG; Eucalyptus saligna Sm. × Eucalyptus maidenii F. Muell., HI) were studied. Several parameters relating to the aforementioned leaf traits were evaluated for 2.5 years. Results: Significant differences in stomatal d and size, RWCc, Ec, and SLA among clones (p < 0.001) and according to the dates (p < 0.001) were obtained. Each clone varied seasonally the characteristics of its new developing leaves to acclimatize to the growth conditions. The pore opening surface potential (i.e., the stomatal d × size) did not affect transpiration rates with full open stomata, so the water transpired under these conditions might depend on other leaf factors. The clones HE, HG, and 12€ were the ones that differed the most from the drought resistant E. globulus control clone (C14). Those three clones showed lower leaf epidermis impermeability (HE, HG, 12€), higher SLA (12€, HG), and lower stomatal control under moderate water stress (HE, HG) not being, therefore, good candidates to be selected for drought resistance, at least for these measured traits. Conclusions: These parameters can be incorporated into genetic selection and breeding programs, especially Ec, SLA, RWCc, and stomatal control under moderate water stress.

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