Individual radial growth model for uneven-aged mixed oak forests in central Korea

Abstract

This study suggested an individual radial growth model for three oak species (Quercus ariabilis, Q. acutissima and Q. mongolica) in mixed and uneven-aged oak stands in central South Korea. The site quality dependent model showed relatively better statistical performance than the site quality independent model. Different components, such as tree age, tree size, competition and growing site, were employed to build and evaluate the individual radial growth model. The components of age, tree size and competition were proven to have significant effects on the tree radial growth. The age and the competition had negative effects on the radial growth, while the tree size had a positive effect. The age effect on the radial growth was greater for larger trees and with lower competition. The tree size was also expected to have a greater effect on younger trees and with lower competition. The competition had greater negative effects on younger and bigger trees. The classical site index, derived from the mean age and dominant height, was proven to not be applicable to the individual radial growth model. Among the topographical factors, only the aspect index was proven to be statistically significant for explaining the radial growth. These analyses of the effects of the different components on the radial growth of oak species were found to be reasonable and consistent with well-known silvicultural experiences.