Effect of intraspecific competition on radial growth and tracheid biometry: A Study of dominant and suppressed trees in a Norway spruce plantation

The present investigation seeks to explore the effects of intraspecific competition on the radial growth and fiber biometry of dominant and suppressed trees within a spruce (Picea abies) plantation. By planting subsequent seedlings among initial saplings, a dichotomous tree population of dominant and heavily suppressed individuals was created. The findings suggest that dominant trees exhibit higher radial growth rates, accompanied by wider, and thicker tracheids as compared to their suppressed counterparts. Although the average tracheid length in the suppressed trees was slightly higher, this difference was not statistically significant. It was observed that tree's social position not only influenced the absolute wood properties, but also impacted the trend of variation in these properties from the pith to the bark, as well as the internal relationships between these features. In essence, suppressed trees display superior wood and fiber quality than dominant ones, although their growth rates are comparatively lower. Based on the results, it is recommended to establish early-stage competition between trees, particularly in the juvenile wood phase, to enhance wood quality.