The effect of varying latewood proportion on the radial distribution of lignin content in a pine stem

The radial distribution of lignin content in a pine stem was compared to la tewood proportion. With the exception of the innermost juvenile growth ring s, a strong negative correlation was found. However, the cell-wall lignin c ontent of low lignin growth rings was equal to that of high-lignin growth r ings. Therefore, the difference in lignin content between individual growth rings was solely due to varying ratios of high-lignin compound middle lame lla to low-lignin secondary wall in thin- and thick-walled tracheids.