Number and Size of Radial Resin Ducts in Slash Pine

Comparative anatomy of resin ducts of the Pinaceae

“…Some information has been reported on the structure, distribution and development of resin ducts in the Pinaceae (Hanes 1927;Mergen and Echols 1955;Werker and Fahn 1969;Fahn 1979;Wu et al 1987;Wu 1990). A few references are also available on the comparative anatomy of the resin ducts (Bannan 1936;Greguss 1955;Gui and Lee 1963;Lee and Mu 1966;Jain 1976), but these studies are limited to a specific genus or organ.…”

Recent Trends in Forest Entomology

“…Horizontal duct density is believed to decrease upward on the stem of ponderosa pine (22), whereas in lodgepole pine there is a tendency for greater densities in the lower part of the bole and in the crown (90), and the duct density of the bole and crown in slash pine was too variable to permit detection of any pattern (42). The yearly production of horizontal ducts in slash and lodgepole pine was highest in the earliest years, decreasing for several decades to the present (62,90); however, this curvilin ear relationship disappeared in older lodgepole pine (90). This early decrease is believed to be due to the greater rate of radial growth rather than to a de crease in duct production.…”

“…The density of horizontal resin ducts is extremely variable within trees and between trees; 60+ per sq cm in spruce and larch (16), 60 to 70 in Scotch pine (77), 50 to 85 in slash pine (62), 35 to 50 in ponderosa pine (22), and 35 to 65 in lodgepole pine (90). Horizontal duct density is believed to decrease upward on the stem of ponderosa pine (22), whereas in lodgepole pine there is a tendency for greater densities in the lower part of the bole and in the crown (90), and the duct density of the bole and crown in slash pine was too variable to permit detection of any pattern (42).…”

Factores anatómicos, dendrométricos y climáticos implicados en la producción de resina de Pinus pinaster AIT. : aplicación a la mejora de los métodos de resinación

“…Para las variables medidas en el corte trasversal se analizaron sus valores medios por orientación y año (anillo de crecimiento) para cada uno de los años de estudio (2007)(2008)(2009)(2010). En el caso de las variables medidas en el plano tangencial se usaron los valores medios del periodo completo por orientación al considerar que estas variables varían poco en el periodo estudiado (4 años) (Mergen & Echols, 1955).…”

“…The mean value per tree for the tangential section was calculated assuming the same number of radial canals during the five years (Mergen and Echols, 1955). For the cross section, the mean value per tree and year (growth ring) was calculated.…”