Spiral and interlocking grain in Eucalyptus dunnii

Abstract

Spiral grain in 181 trees from a 9-year-old plantation-grown Eucalyptus dunnii was normally distributed with mean -0.33 degrees (to the left) and standard deviation 1.7 degrees, and was affected by family and by crown asymmetry. Interlocking grain was common, exhibiting a mean amplitude of 3.4 degrees (standard deviation 1.5°) and a mean wavelength of 39 mm (standard deviation 12 mm). The relatively large amplitude of interlocking grain means that most trees will have spiral grain that alternates between left and right during each year. The wavelength of interlocking grain is influenced by tree size, but amplitude of interlocking is under genetic control. Both spiral grain and the amplitude of any interlocking were heritable (h 2 =0.99 and 0.63 respectively).

Wood Characteristics

“…Many tropical trees, especially upper-story trees, periodically alternate the direction of their grain (Knigge and Schulz 1959), even between the early-and latewood of a growth zone (Thinley et al 2005). This characteristic is often called interlocked grain.…”

Relação da grã com algumas variáveis do crescimento e propriedades da madeira de Khaya ivorensis

“…As relações do MAD com outras propriedades mecânicas foram avaliadas por França (2014), Onchieku et al (2013), Thinley et al (2005), que observaram que o MOR e MOE foram negativamente afetados pelos desvios da grã. A mesma relação foi observada por Hernández e Almeida (2003), no estudo do efeito da grã intercruzada na resistência ao cisalhamento da madeira de A. cearensis, A. macrocarpon e C. racemosa.…”

Forestry at Southern Cross University: fifteen years in review

“…Thus oral presentation and writing skills are emphasised within SCU's degrees, and students are encouraged to publish research arising from honours (e.g., Pelletier et al 2008), graduate diploma (e.g., Thinley et al 2005) and doctoral programs (Angel et al 2008, Bristow et al 2006, Grant et al 2010, Kariuki et al 2006a,b, Leys and Vanclay 2011a.…”