The investigation for the conservation of the Fagus crenata forest in southern limit of distribution area

分布区南缘水青冈林保护调查

• 批准号: 10660151
• 负责人: ISHII Hiroshi
• 金额: $ 1.47万
• 依托单位: KAGOSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10660151/
• 关键词: Fagus crenata; Southern limit of distribution; Regeneration; 南限地

The structure of beech (Fagus crenata) stands and the regeneration regimes of beech were investigated at the ridge in Mt. Takakuma, which is the southern limit of beech distribution.(1) The height of beech in Takakuma is suppressed compared with the radial growh or the horizontal extension of the crown when the beech was taller than the shrub layer. Poor dominance of canopy tree species may be an indirect reason for such a change in the trade-off relationship between vertical and horizontal growth. However, although the height of beech in Takakuma was suppressed, death of beeches or obvious declines of radial growth were not observed.(2) The density of the basal area and beech trees in Takakuma was as low as that of other Pacific Ocean type beech forests. The proportion of small trees with <10cm in Dbh to canopy trees with >20cm in Dbh was lower in 0.5. Furthermore, there were no saplings less than 2m in height even though Sasa was absent, although the gap ratio exceeded 50% in Mt. Takakuma.(3) The nut production vas large in 1998, however there were remarkably few viable nuts because the proportion of empty nuts was nearly 80%. Although the mortality of nuts in winter season was low, there were no current seedlings whether Sasa was removed or not in the autumn of the mast year.(4) The beech in Takakuma did not regenerate successfully, and other canopy tree species or the community of shrubs with Sasa may replace the beech stands.

研究了高山山毛榉（Fagus crenata）林分结构和山毛榉更新机制。高山山毛榉是山毛榉分布的南部边界。(1)当高过灌木层时，高沼山毛榉的高度与树冠的径向生长和水平伸长相比受到抑制。冠层树种优势度差可能是造成这种垂直生长与水平生长权衡关系变化的间接原因。然而，虽然高间山毛榉的高度受到抑制，但没有观察到山毛榉的死亡或径向生长的明显下降。(2)高库马基区和山毛榉树密度与其他太平洋型山毛榉林密度相同。胸径<10cm的小树在胸径>20cm的冠层乔木中所占比例在0.5时较低。高熊山的林隙率超过50%，但在没有莎莎的情况下，没有低于2米的树苗。(3) 1998年果仁产量大，但可活果仁少，空果仁占比近80%。尽管冬季果仁死亡率较低，但在盛年秋季无论是否拔除，均无现苗。(4)高库马山毛榉林分再生不成功，其他冠层树种或莎莎灌木群落可能取代山毛榉林分。