Development of the Site Index Curves for Quercus acuta Stands

Development of the Site Index Curves for Quercus acuta Stands

Background and objective: The purpose of this study is to develop a model for estimating the site index (SI), which is thecriterion for determining the site productivity of the Quercus acuta stand as known as Evergreen broad-leaved tree (EBLT)species. Methods: The materials used in the analysis were data from 63 sample plots, and the sample plots data were collected fromthe National Forest Inventory (NFI) and other sites. Since the site index is determined by the height and stand age of thedominant trees, the Schumacher model, the Chapman-Richards model, and the Weibull model were applied to derive theoptimal equation for estimating the dominant tree height. Results: The three models derived the parameters and went through a statistical test. Among the three models, theChapman-Richards model was found to be optimal considering the fitness index, bias, and residuals. By transforming thismodel, site index estimation equations with the reference age of 30 years were created, and site index curves werederived. According to the analysis of the collected data, the site index of the Quercus acuta stand in Korea was found tobe in the range of 10 to 16. Conclusion: As the growth distribution of Quercus acuta is expected to move north due to climate change, the derivationof the site index representing site productivity will be helpful in making policy and management decisions for this species.