Studies on the management of the natural broad leaved forest II : Stand composition of the forest on the stand of different topography (Forestry Experiment Station)

1本調査は, 天然生広葉樹林分の施業の資料とするため実施された。調査地は, 琉球大学与那演習林内に設定した。2上層木の樹種は, I区(NE斜面)で30種, II区(SW斜面)で15種であった。3各調査区の主林木はイタジイであって, その他の主要木としてイジュ, コバンモチ, ヒメユズリハ, エゴノキ, モツコクなどが出現する。4一般に, 地形別で立木本数は下腹部で減少し, 稜線部で増加する傾向が認められた。また平均樹高および材積は, 稜線部で低下する。5主要木の中で, エゴノキは下腹部での出現率が高く, ヒメユズリハ, モツコクは稜線部で出現率が高い。6下層木の優占種は, 上層木と同様にイタジイである。7実生木および萠芽木の生育本数割合は樹種によってちがいが認められた。1. The reserch was in order to obtain data for management of the broad-leaved foret. The plot setted in Yona experiment forest of University of the Ryukyus. 2. There were 30 species in upper tree in the plot I, NE direction slope, and were 15 species in the plot II, SW direction slope. 3. The dominant species of the upper tree in each plot was Castonopsis Sieboldii and other main species were Schima Wallichii ssp. liukiuenssis, Elaeocardus japonicus, Daphniph yllum Teijphyllum, Styrux japonicus, Ternstroemia japonicus. 4. In each topography, number of the tree was inclease in the lower slope and mean tree hieght and volume was decrease in the creast, 5. In the main species, Styrux japonicus occured in the lower slope, Daphniphillum Teijphyllum and Ternstroemia japonicus occured in the crest. 6. The dominant species of under tree was Castanopsis Seiboldii. 7. The percentage of seedling and sprouted tree in under tree showed difference between species