The aim of this study was to clarify the structure and regeneration status of mixed beech (Fagus crenata) forest on Mt. Toishi in the Sangun mountain range in northern Kyushu, a relatively low-latitude region in Japan, with emphasis on forests at lower elevations. We focused on a mixed beech forest at a low elevation of Mt. Toishi and compared the forest structure of the target stands, including tree species and size, with the forest structure near the peaks of Mt. Toishi and Mt. Sangun. Deciduous broad-leaf trees were dominant near the peaks, while evergreen broad-leaf trees dominated at lower elevations, whereas the relative dominance of beech trees was not significantly different. Near the peaks, the number of large-diameter beech trees forming the canopy decreased, and small-diameter trees were present. The proportion of small-sized trees was lower in the low-elevation forest area than in the forest area near the peak. Even at lower elevations, juvenile beech trees grew in limited areas on steep slopes along forest roads. These sites suggested that regeneration of beech populations is possible even at low elevation.

中文翻译：

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日本暖温带北部九州北部土石山低海拔山毛榉混交林特征

本研究的目的是明确日本九州北部三群山脉Toishi山山毛榉（ Fagus crenata ）混交林的结构和再生状况，该地区是日本相对低纬度的地区，重点关注低海拔地区的森林。我们以丰石山低海拔地区的山毛榉混交林为中心，将目标林分的森林结构（包括树种和大小）与丰石山和三群山山峰附近的森林结构进行了比较。山峰附近以落叶阔叶树为主，低海拔地区以常绿阔叶树为主，而山毛榉的相对优势度差异不显着。在山峰附近，形成树冠的大直径山毛榉树数量减少，出现了小直径树木。低海拔林区小型乔木比例低于高峰林区。即使在海拔较低的地方，山毛榉幼树也只生长在森林道路沿线的陡坡上的有限区域。这些地点表明，即使在低海拔地区，山毛榉种群的再生也是可能的。