Eleven years forest dynamics of deciduous broadleaved forest in eastern Hokkaido, Japan.

北海道東部に位置する九州大学北海道演習林内の3地点（拓北，美盛，花輪）の落葉広葉樹林において最長11年間の毎木調査を行い，直径階分布，新規加入率と死亡率，地上部現存量を比較した。拓北および美盛プロットではリタートラップにより落葉落枝・落下種子のサンプリングを行った。2015年時点では拓北プロットに32樹種481個体が確認され，L 字型の直径階分布を示した。美盛および花輪プロットではそれぞれ17 樹種428個体，20樹種510個体が存在し，いずれも一山型の直径階分布を示した。花輪プロットは新規加入率と死亡率が拓北や美盛プロットに比べて高かった。2015年の地上部現存量は拓北と美盛プロットがそれぞれ94.9t/ha，92.8t/ha に対し花輪プロットは49.2t/ha と少なかった。拓北および美盛プロットの落葉落枝・落下種子量には年変動があったが両プロット間での明瞭な同調性は認められなかった。Three plots in deciduous broad-leaved forest (Takuhoku, Bisei, Hanawa) have been surveyed for long-term ecological research in the Ashoro research forest, Kyushu University. All tree trunks whose girth at breast height (1.3m height from grand level) are larger than 15cm, were identified and the diameter of breast height (DBH) were measured for tree inventory data. Also, we established 25 litter traps in each of Bisei and Takuhoku plots to assess the litter fall and seed productions. The tree inventory data at Takuhoku plot showed 32 tree species and 481 individuals in 2015. The frequency distribution at Takuhoku plot were L-shaped. On the other hands, 17 species and 428 individuals, 20 species and 510 individuals were observed in Bisei and Hanawa plots, respectively. The frequency distribution of DBH were unimodal at Bisei and Hanawa plots. The recruitment and mortality rate at Hanawa plot were apparently higher than those of Takuhoku and Bisei plots. Above ground biomass of Takuhoku and Bisei plots were 94.9t/ha, 92.8t/ha, respectively, which were much larger than that in Hanawa plot (49.2t/ha). The litter fall of Takuhoku and Bisei plots showed annual fluctuation. However, synchronization of the litter fall fluctuation between Takuhoku and Bisei plot was unclear