TEF plot

The study site was the Tomakomai Experimental Forest (TEF; 42°40′ N, 141°36′ E) permanent plot located in central Hokkaido. The TEF plot was located on a flat plateau with inclines of <5° and elevations ranging from 20 to 90 m. The mean annual temperature and precipitation were 7.0°C and 1200 mm, respectively. The soil in the TEF is typically of volcanic origin. No. 15 typhoon removed 49% of standing trees (diameter at breast height [DBH] ≥ 5 cm) and 81% of basal area in September 1954. The TEF plot was established in 1958 and the pre-disturbance condition was reconstructed based on the first measurements made after the windthrow. The pre-disturbance forest type was hardwood dominated by Quercus spp., Acer spp., Ostrya japonica, and Tilia spp. All trees with a DBH (1.3 m above the ground) ≥ 5 cm were identified and measured during every survey. Tree measurement was taken 10 times 65 years after the windthrow. Salvage logging was not conducted; no trees were harvested after the windthrow. A permanent plot measuring 50 × 50 m (0.25 ha) was set up in 1958. The taxonomic nomenclature used here follows Yonekura and Kajita (2003–).

本研究的样地为位于北海道中部的苫小牧实验林（Tomakomai Experimental Forest, TEF）永久样地，地理坐标为北纬42°40′、东经141°36′。该TEF样地地处坡度小于5°的平坦高原，海拔范围为20至90米；年平均气温7.0℃，年降水量1200毫米。样地土壤多为火山成因。1954年9月，第15号台风造成样地内49%的立木（胸径[diameter at breast height, DBH]≥5厘米）倒伏，林分断面积损失81%。TEF样地于1958年设立，其扰动前的林分状态基于台风风倒后的首次调查数据重建。扰动前的森林类型以阔叶硬木林为主，优势种包括栎属（Quercus spp.）、枫属（Acer spp.）、日本鹅耳枥（Ostrya japonica）及椴树属（Tilia spp.）。历次调查均对所有胸高（距地面1.3米）≥5厘米的树木开展物种鉴定与尺寸测量。台风风倒事件发生65年后，累计开展了10次树木监测工作。该样地未实施打捞性采伐，台风扰动后未采伐任何林木。1958年设立的永久样地面积为50×50米（0.25公顷）。本研究采用的分类命名体系遵循Yonekura与Kajita（2003–）的标准。