A study was conducted to quantify the relationship between southern pine beetle infestation growth and the intertree spacing in old growth pine stands. The problem with extrapolating the results of previous studies to old growth stands is that it is unclear whether the same mechanism will operate in stands of older trees characterized by double the diameter (20-25 cm vs. 40-60 cm). In this study we focused on experimentally answering the question of how three levels of thinning (resulting in different average intertree distances) affect the rate of SPB infestation growth in mature loblolly pine stands, over 60 yr old and over 40 cm average dbh. We also included a hardwood removal treatment. Both intermediate and severe thinning had a strong negative effect on the rate of infestation growth. The effects of intermediate and severe thinning were similar; there was no statistically detectable difference between these two treatments. Hardwood removal appeared to decrease infestation growth rate compared to no thinning, but this effect was not statistically significant. South. J. Appl. For. 23(4):193-196.
Document Type: Journal Article
USDA Forest Service, Pacific Northwest Station, 1401 Gekeler Lane, La Grande, OR 97850
Publication date: November 1, 1999
More about this publication?
Each regional journal of applied forestry focuses on research, practice, and techniques targeted to foresters and allied professionals in specific regions of the United States and Canada. The Southern Journal of Applied Forestry covers an area from Virginia and Kentucky south to as far west as Oklahoma and east Texas.