Stand Structure and Maintenance of <Emphasis Type="Italic">Picea jezoensis</Emphasis> in a Northern Temperate Forest,South Korea

Stand structure and spatial distribution of Picea jezoensis (Siebold et Zucc.) Carrière on Mt. Gyebang, Korea was investigated to provide information on the structural characteristics and the maintenance of P. jezoensis population in northern temperate mixed coniferous forests. Height and diameter at breast height (DBH) distribution, age, growth, and spatial distribution patterns of P. jezoensis were examined in thirty nine 100-400 m² quadrats or circular plots. The overall stand structure attributes in the study sites are stem density of 709 trees ha⁻¹, a mean DBH of 12.8 cm, and a mean height of 5.6 m, with reverse J shapes of DBH and height distributions. The stem density of P. jezoensis population was 81 trees ha⁻¹, a mean DBH of 20.7 cm, and a mean height of 9.1 m, showing bimodal-like shapes in age and DBH distributions. Several growth release periods implied that P. jezoensis stands experienced small disturbances. The radius of patches of similar-sized P. jezoensis in the variogram was equivalent with the height of the tallest trees, indicating that patches were established following the fall of trees in the upper canopy layer. Small windthrows in this region contributed to the maintenance of the P. jezoensis stand by releasing sapling growth and providing nursing logs and space for seedlings.