The relationships between tree size and spatial distribution of foliage-mass within crowns of Japanese cedars (Cryptomeria japonica) in young plantations

摘要

The spatial distribution of foliage-mass within the crowns of Japanese cedars (Cryptomeria japonica D. Don) was measured for trees of different sizes. The horizontal changes of three indices (the crown depth of the foliage layer, Cd(r) the relative depth of the maximum foliage along a vertical line, R(r) and the mean foliage-mass density from the crown surface to 1 m in depth, F(r, 1)) were analyzed. The tree size related to the horizontal distribution of the foliage. The vertical size of the foliage space represented by Cd(r), had a positive relation to the relative tree size in the stand, not to the absolute tree size. Hence, dominance is an important factor in vertical foliage distribution. In contrast, the absolute tree size was related to the pattern of the horizontal foliage distribution, which is represented by the horizontal change of F(r, 1). Therefore, a spatial foliage distribution profile could be represented well using these indices. An empirical model was constructed for estimating the foliage mass density, using the relationships between the tree size and the three indices.