Use of Beta Regression to Estimate the Volumetric Yield Coefficient in Logs of Native Species of the Legal Amazon

Abstract

The research was developed at a logging site within the Legal Amazon and its main objective was to quantify the percent yield of the logging process for each species. In addition, the objective also included verifying the possibility of using the log's conicity to estimate their yield. Nine (9) logs were randomly selected from each of the 19 native species available at the sawmill, totalling 171 studied logs. The adopted methodology was based on a resolution from the Environmental National Council (CONAMA). Using the Software R, one beta regression model was developed based on the yield and conicity data. In the joint analysis of the data, the coefficient of volumetric yield (CVY), of all species was above the minimum required by current legislation. The use of the species and log's conicity as a functional dependence to estimate the yield of sawn wood showed high reliability, which justifies its application. Thus, the obtained statistical model may become a useful tool for the planning and management of the processing of logs from native species of the Legal Amazon.

Volumetric yield coefficient: the key to regulating virtual credits for Amazon wood

“…Since the virtual credits are the functional currency of the DOF system, the monitoring agency will therefore consider that the remaining 1166.5 m³ of this unfulfilled conversion would still be available as unprocessed logs in the company's log deck. Given the variable mean volumetric yield among the sampled species, and among tropical Amazonian timber species in general (Mendoza et al 2019;Santos et al 2019;Lima et al 2020) it becomes clear that attributing a fixed value to CRV based on a general average does not match the reality of yield variations across the various aspects involved in industrial comercial timber production (multiple species, products and processing lines, among others). This makes the control process ineffective and may favor the illegal log trade.…”

Quality of raw material and yield of exported sawn wood in the rational use of tropical timber from the Amazon

“…Normally, this is manifested in generation of a large volume of waste, which causes an increase in the cost of the nal product. Although recent studies have been conducted to evaluate the sawn timber yield of Amazonian species (Santos et al 2017;Mendoza et al 2019;Stragliotto et al 2019; Lima et al 2020). There is little information on the yield of tropical species for the Amazon region, despite the potential of wood and the important role of this region in supplying this raw material to the market (Luz et al 2021).…”