Abstract: In order to understand the characteristics of cork qualities of Q. variabilis, and to provide scientific base for managing the forests, the differences of two types of Q. variabilis with different periderm thickness, distributed in sunny slope of North Slopes Qinling Mountains, were studied at the various DHB stages. Totally 40 Q. variabilis trees were used in this study. The results showed: There was extremely significant difference in the periderm thickness between sunny side and shady side of the stems. The cork of the thick type Q. variabilis was better than the thin type’s. The cork of the two types of Q. variabilis was worst at 10~20 cm DBH stage. There was an extremely significant and positive correlation between periderm thickness and tree growth. Stepwise regression analysis showed that DBH could replace age used as an important index for estimating the periderm thickness. With the increase of cork thickness the cork quality was relatively better in the two types. The growth of the thick type was faster during 10~30 cm DBH stage, and then slowed down after 40 cm DBH. In the contrast, the growth of the thin type was always slow. In the future, barks of the thick type should be stripped timely when DBH arrives at 30 cm, and the thin type should avoid stripping when DBH is less than 20 cm. Meanwhile, appropriate thinning techniques should be used to improve the number of forest gaps, thereby increasing the heterogeneity of light, temperature and other environmental resources, and providing favorable conditions for growth and development of the cork of the Q. variabilis.

Key words: Q. variabilis, periderm, cork, DBH, correlation analysis, regression analysis