Jozankei plot

The study site was the Jozankei (42°57′ N, 141°12′ E) permanent plot in the Japanese National Forest, located in central Hokkaido. The Jozankei plot was located on a 35° slope at an elevation of 400–500 m. The mean annual temperature was 9.2°C and precipitation was 1,192 mm. Mesic brown forest soil occurs at the site. No. 15 typhoon removed 82% of standing trees (diameter at breast height [DBH] ≥ 5 cm) and 86% of basal area in September 1954. The Jozankei plot was established in 1956 and the pre-disturbance condition was reconstructed based on the first measurements made after the windthrow. All trees with a DBH (1.3 m above the ground) ≥ 5 cm were identified and measured during every survey. Tree measurement was taken 11 times 65–66 years after the windthrow. Salvage logging was not conducted; no trees were harvested after the windthrow. A permanent plot measuring 70 × 70 m (0.49 ha) was set up in 1956; a buffer zone of 1.46 ha was established. Before the windthrow in 1954, conifers and hardwoods in the mixed forest accounted for 57% and 43% of tree basal area, respectively. Abies sachalinensis was dominant in the plot, where 18 other tree species, such as Picea spp., Acer pictum, Quercus. crispula, and Tilia japonica, occurred. The taxonomic nomenclature used here follows Yonekura and Kajita (2003–).