Annex III of Resolution 411/09 – Studies to Determine the Highest Volumetric Yield Coefficient of Commercial Log in Sawn Timber Valid for Yield Coefficient Greater than the One Set Out in Annex II



Presenting roadmap for technical-scientific studies with a view to changing the volumetric yield coefficient determined by the present resolution, to the transformation of commercial log into sawn timber..


The volumetric yield coefficient (CRV) determined by this Resolution will be adopted by the competent environmental agency for the conversion of wood logs of tropical hardwood species into sawn timber. The CRV varies according to the species, the quality of the raw material, the kind of industrial process, the technology level of industry, type and quality of the final product, the realization of commercial use.

Due to the uniqueness in the establishment of a CRV that complies with specifically all industries, this Resolution provides that the competent environmental agency can accept, through technical analysis, specific CRVs, provided that the applicant companies submit satisfactory scientific studies.


3.1 Characterization of the company

3.1.1 General information Industry Name Geographical coordinates Postal address, telephone, fax and e-mail Name and function of contact person IBAMA Registry

3.1.2 Equipment

List equipment (platform of logs, saw logs, carriage-of-tape, circular saw, circular saw, Planer, greenhouse, cross and others), and the related quantities, year of manufacture, power and other technical specifications.

3.1.3 Products Generated List the main final products produced in the last 12 months. List the byproducts sold by company (pre-cut, short, blockboard, packaging and other) within the past 12 months. List the types of waste generated and used by the company

3.2 Selection of species and logs for the study to justify the selection of the species included in the study.

The selection of logs for the study should be done by species, according to the method of simple random sampling.

3.3 Cubage of logs processed. Information about the logs processed should be grouped into spreadsheets for each of the studied species. The worksheets for each species should be included in the ANNEX to the technical-scientific report presented.

3.3.1 Wood species to identify the species studied by common and scientific name.

3.3.2 Dimensions of logs Diameter: Determine the crossed diameters (larger and minor), without considering the shell at both ends of the log. Cubing log sheets must present the four values of diameters determined for each log, using the meter (m) as the unit of measure. Length: determine the smallest and largest length of the log . These values should appear on the cubage sheets presented, using the meter (m) as the unit of measure.

3.3.3 Determining the volume of the log

The volume of logs must be determined by the geometric method, i.e. using Smalian’s equation. The average of the diameters and the average of the lengths should be used to the computation.

3.4 Determination of the volume of sawn timber

The information on the volume of sawn timber, obtained from the processed logs, should be grouped into spreadsheets for each of the studied species. These worksheets should be included in the ANNEX to the technical- scientific report presented.

3.4.1 Dimensions of parts produced

For each sampled log, inform the dimensions (length, width and thickness) of parts produced and the quantities.

3.4.2 Sawn timber volume

For each sampled log, determine the volume of sawn timber obtained from the amount of pieces.

3.6 Determination of the volumetric yield coefficient (CRV)

The CRV is determined by the ratio between the volume of logs processed and the volume obtained from sawn timber properly marketed. Should be determined by the average of the CRV species determined individually for each log.

3.7 Statistical analysis

3.7.1 Descriptive statistics

Determine the mean, variance, standard deviation and coefficient of variation for each species studied. 3.7.2 Determination of optimal size of the sample for the CRV determined is representative of the species and its product, should be given the optimal size of the sample, assuming a 10% error on the average value of the CRV. The number of studied logs should always be equal to or greater than the number given to the optimal size of the sample.

3.7.3 Determination of confidence interval

Determine the confidence interval at the 95% level of probability with lower and upper bounds that the CRV may entail for certain species.

3.8 Coordination, supervision and conduct of work

The technical-scientific study should be signed by legally qualified professional with due note of technical responsibility and legal representative of the company.