Master of Science (MS)


Renewable Natural Resources

Document Type



In 1994, a 17 yr old, slash pine spacing study was thinned to 35% of the maximum stand density to evaluate the influence of prethinning stand conditions on postthinning growth after thinning to a common stand density. It was expected that plots thinned to a common growing stock level should have equal growth increments and if growth was not equal then the difference was related to prethinning stand conditions. Stand growth variables of quadratic mean diameter increment, stand-level basal area increment, and gross-volume increment were evaluated to determine the influence of initial spacing, stand density, and prethinning crown size before thinning and for 5 years after thinning. Lower values of relative stand densities were associated with initially wider spacings before thinning and higher values 2-5 yr after thinning. Before thinning, quadratic mean diameter increment was positively related to initial spacing and prethinning crown dimensions and negatively related to relative stand density. After thinning, quadratic mean diameter increment was not significantly influenced by initial spacing, but it was inversely correlated with prethinning crown ratio 5 yr after thinning as relative stand density increased. Stand-basal area increment was negatively correlated with prethinning crown width, crown ratio, and crown volume before thinning, but it was not significantly related to initial spacing or relative stand density before or after thinning. Gross-volume increment was positively influenced by initial spacing and prethinning crown dimensions and negatively related to relative stand density prior to thinning. These positive relationships were observed during yr 2, 3, and 4 after thinning where wider initial spacings produced larger increments in volume as relative stand densities increased. Prethinning crown dimensions remained correlated with gross-volume increment after thinning. However, after thinning, these correlations with prethinning crown dimensions held a consistent relation with postthinning growth and also conformed to conventional growth-growing stock relationships as stands developed. The significant relationships detected between gross-volume increment and initial spacing, prethinning crown dimensions, and relative stand densities support that prethinning tree characteristics affected postthinning gross-volume increment for the duration of this study.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Thomas Dean