<b>Sampling sufficiency of the anatomical characteristics of Brazilian hardwood using the resampling method

Abstract

ABSTRACT. Sampling sufficiency of the anatomical characteristics of fibres from Luehea divaricata wood was investigated through the bootstrap resampling method. Sampling sufficiency of fibre length, fibre diameter, lumen diameter and fibre wall thickness were determined. Three scenarios of sampling sufficiency evaluation were used: general, segregation between juvenile and mature wood, and accumulation throughout the life of the tree. The segregation of juvenile and mature wood showed that sampling sufficiency in juvenile wood was higher than in mature wood, up to three times for the fibre length. In general, results indicated higher values than suggested in specific standards and by other authors. Therefore, resampling bootstrap methodology, even though underused in forestry research, is an alternative for new studies, as it does not have restrictive hypotheses such as data normality.Keywords: bootstrap, juvenile wood, mature wood, Luehea divaricata, sample size. Suficiência amostral das características anatômicas da madeira usando o método de reamostragem RESUMO.A suficiência amostral das características anatômicas das fibras da espécie Luehea divaricate foi investigada utilizando o método de reamostragem bootstrap. Foram determinadas as suficiências amostrais do comprimento da fibra, do diâmetro da fibra, do diâmetro do lúmen e da espessura da parede da fibra. Três cenários de avaliação da suficiência amostral foram usados: geral, segregação entre lenhos juvenil e adulto, e acumulação durante toda a vida da árvore. Para o cenário de segregação entre lenhos juvenil e adulto, verificou-se que a suficiência amostral no lenho juvenil foi superior à do lenho adulto, chegando a ser três vezes maior para o comprimento da fibra. Os tamanhos amostrais determinados foram, de maneira geral, superiores aos sugeridos por normativas da área e utilizados por outros pesquisadores. Dessa forma, a metodologia de reamostragem bootstrap, até hoje pouco usada na área florestal, surge como alternativa para trabalhos futuros, já que não possui hipóteses restritivas, como a normalidade dos dados.Palavras-chave: bootstrap, lenho juvenil, lenho adulto, Luehea divaricate, tamanho amostral.

Effects of thermal treatment and weathering in the resistance against termites of a fast-growing pine wood

“…Anatomical images were taken from 13 µm thick wood blades using an optical microscope adjusted for 25 × and a processing program called ImageJ. Based on these images, 60 wood cells were measured by each group, as recommended by Missio et al (2014). Chemical groups were qualitatively evaluated in previously milled, ground (200 mesh screen) and pressed samples by Fourier-transform infrared spectroscopy (FTIR) coupled with an ATR device using a Shimadzu IRSpirit equipment.…”

Sampling sufficiency for mechanical properties of wood

“…It estimates the accuracy of means, medians, variances, and percentiles of sampling by using subsets of the available data or randomly generating new samplings by resampling the data set (Edwards et al 2011). The resampling methods such as Bootstrapping (Edwards et al 2011, Missio et al 2014, Jackknifing (Wang and Yu 2020), Permutation (Fieberg et al 2020) and Cross-Validation (Shimodaira 2016) have been used for estimating the sample sizes in many areas, such as anatomy (Missio et al 2014), ecology (De Patta Pillar 1998), biomedicine (Dwivedi et al 2017), zoology (Dimauro et al 2009), and genetics (Kess and El-Kassaby 2014).…”