Anabel Aparecida de Mello, Leif Nutto, Karla Simone Weber, Carlos Eduardo Sanquetta, Jorge Luis Monteiro de Matos, Gero Becker. (2012). Individual biomass and carbon equations for Mimosa scabrella Benth. (bracatinga) in southern Brazil. Silva Fennica vol. 46 no. 3 article id 44. https://doi.org/10.14214/sf.44

Keywords: carbon offsets; forest inventory; firewood; modeling; tree compartments

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Mimosa scabrella Benth. is an important native species of southern Brazil widely used for energy and promising for reforestation carbon offsets. Quantification of biomass and carbon stock is valuable for both purposes. From a forest inventory conducted in southern Brazil, data of M. scabrella were analyzed. Thirty sample trees were felled, excavated and weighed in the field and brought to laboratory for biomass and carbon determination. The total aboveground biomass represented 85% of the tree biomass, while roots corresponded to 15%. Correlation matrix of diameter at 1.3 m height (D), tree height (H) versus total and compartment biomass (P) indicated strong association between tree dimensions and biomasses. Five regression models were tested and equations were fitted to data of five biomass compartments and total tree biomass. The best fitting model for total biomass was P = –0.49361 + 0.034865 x D²H whereas for the partial biomass of the compartments was lnP = β₀ + β₁ x ln(D) + β₂ lnH. Carbon concentration was statistically significantly different in foliage than in other compartments. Three approaches of calculating carbon stocks were evaluated and compared to actual data: 1) Estimated total biomass x weighted mean carbon concentration; 2) Estimated partial (compartment) biomass x compartment average carbon concentration; and 3) Carbon regression equations. No statistical difference was detected among them. It was concluded that biomass equations fitted in this study were accurate and useful for fuelwood and carbon estimations.

de Mello, Federal University of Sergipe, Brazil E-mail: aadm@nn.br
Nutto, Federal University of Paraná, Brazil E-mail: lnutto.ufpr@gmail.com
Weber, Federal University of Paraná E-mail: ksw@nn.br
Sanquetta, Carlos Eduardo Sanquetta E-mail: ces@nn.br
Monteiro de Matos, Jorge Luis Monteiro de Matos E-mail: jlmdm@nn.br
Becker, University of Freiburg, Institute of Forest Utilization and Work Science, Germany E-mail: gb@nn.de

article id 187, category Research article

Tobias Biechele, Leif Nutto, Gero Becker. (2009). Growth strain in Eucalyptus nitens at different stages of development. Silva Fennica vol. 43 no. 4 article id 187. https://doi.org/10.14214/sf.187

Keywords: growth stress; growth strain; Eucalyptus nitens; stages of development; sawnwood

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Eucalypts are renowned for their high growth stress levels. These stresses cause splitting, warping and dimensional instability when cutting, processing and drying the wood. In Chile, large Eucalyptus nitens plantations can be found, which, due to these problems, are scarcely utilised for solid wood products (veneer, sawn wood). This study aims to determine the factors influencing growth stress at different stages of tree’s development, and to identify whether the factors influencing growth stress change over time. In five stands of different ages, growth strain, as an indicator of growth stress, was measured at different tree heights with the single hole drilling method. The tree variables DBH, tree height, slenderness (height/diameter ratio) and crown parameters also were measured. A correlation analysis of tree variables and growth strains was undertaken. The results obtained indicate a high variability in growth strain values. It was concluded that growth strain is not correlated with a single growth parameter, but with a combination of factors that variously influence it at different ages and tree heights.

Biechele, University of Freiburg, Institute of Forest Utilisation and Work Science, Werthmannstr. 6, DE-79085 Freiburg, Germany E-mail: tobias.biechele@fobawi.uni-freiburg.de
Nutto, University of Freiburg, Institute of Forest Utilisation and Work Science, Werthmannstr. 6, DE-79085 Freiburg, Germany E-mail: ln@nn.de
Becker, University of Freiburg, Institute of Forest Utilisation and Work Science, Werthmannstr. 6, DE-79085 Freiburg, Germany E-mail: gb@nn.de

Category : Research note

article id 1026, category Research note

Leif Nutto, Ricardo A. Malinovski, Martin Brunsmeier, Felipe Schumacher Sant’Anna. (2013). Ergonomic aspects and productivity of different pruning tools for a first pruning lift of Eucalyptus grandis Hill ex Maiden. Silva Fennica vol. 47 no. 4 article id 1026. https://doi.org/10.14214/sf.1026

Keywords: forest management; wood quality; work science; handsaw; shear

Highlights: Pruning of hardwoods coming from forest plantations is becoming more and more important in Brazil to replace scarce wood from tropical forests; Evaluating productivity of different pruning tools is essential for the economic output of plantations managed for high quality wood; Pruning activities of forest workers can be classified as “hard” or “very hard work”. Depending on the tools used physical long-term damages may be prevented.

Abstract | Full text in HTML | Full text in PDF | Author Info

For the substitution of wood from tropical rainforests pruning of Eucalyptus for producing valuable hardwoods in short rotation plantations has become important. Existing tools and ergonomic aspects of pruning were not yet well analysed under these conditions. The objective of the study is to evaluate the productivity and ergonomics of three different pruning tools in a pruning lift up to 3 m in height. The trees used in the study came from an 18-month-old clonal Eucalyptus grandis stand planted in a 5.0 x 2.8 m spacing. Two manual pruning tools and an electric shear were tested for productivity by using time studies. Ergonomic aspects were evaluated by two test persons using pulse meter equipment. The highest productivity could be shown for the electric shear (236 trees per working day), followed by the manual shear (196 trees/day) and the handsaw (180 trees/day). The heartbeat rate of the two test persons ranged from a level of “very hard work” for the manual tools to “middle hard” and “hard work” for the electric shear. The workload level to achieve the productivity currently reached in practice using purely manual tools is extremely high, exceeding the permanent working capacity of the operators and leading to physical degradation on the long run.

Nutto, Department for Forestry, Federal University of Paraná, Av. Pref. Lothário Meissner, 632, Curitiba, PR, Brazil E-mail: lnutto.ufpr@gmail.com
Malinovski, Department for Forestry, Laboratory of Forest Operations, Federal University of Paraná, Av. Prefeito Lothario Meissner, 900, Curitiba, PR, Brazil E-mail: ricardo@colheitademadeira.com.br
Brunsmeier, Chair of Forest Utilization, University of Freiburg, Werthmannstraße 6, 79085 Freiburg, Germany E-mail: martin.brunsmeier@fobawi.uni-freiburg.de
Schumacher Sant’Anna, Department for Forestry, Laboratory of Forest Operations, Federal University of Paraná, Av. Prefeito Lothario Meissner, 900, Curitiba, PR, Brazil E-mail: felipe@colheitademadeira.com.br

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