高山林の施業に関する研究(第1報)林分構造並びに年齢構成について

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We investigated about forest structure, existing state of trees, structure of crown and stand age for the purpose of fundamental studing on the reasonable treatment of inaccessible forest. A. On the structure of stand. 1. According to, result of investigation, the lower regions are in general hard wood superior type; number of trees and volume of this stand are both overcome other species and growth of secondary stand and young growth are remarkable, and if transition does go on under this condition, it goes without saying that hard wood will have come to acquire superior position increasingly. Therefore when we carry out treatment of soft wood commercial forest, it is desirable to treat so as to bring about increase of growing stock and increment of forest, and to force down the influence of hard wood in these stand, and to care the succeeding trees of soft wood. 2. The middle regions seem to regard as transition point from hard wood superior type to Tsuga diversifolir Mast. superior type. They present complicature of forest, but in general, there is a tendency to become superior by Tsuga diversiforia Mast. in case of topography and site condition of stand are not suitable; and have a tendency to become superior by hard wood in case of site and forest condition are suitable. 3. The upper regions are generally T. d. Mast superior type; their volume ratio of stand run up into 47-65 per cent, and overcome other species. Distribution of number of trees and volume in diameter class increase in proportion as smaller diameter to larger. These distributions show a triangle up set down, are characteristic phenomenon in this type. 4. In the over matured forest such as this area, corresponding to 30 per cent out of existance trees are dead standing trees, which is due to suppression by upper crown or other injury; and 35-40 per cent of these are small diameter class or sub tree-crops, and the growing stock of these is about 20 per cent. In these natural forest such amount of growing, stock is reducting into forest as dead standing trees. B. On the existing state of trees. We investigated about existance and distribution state of main tree-crops, sub tree-crops, seedlings and dead standing trees, and about state of crown and tree-class in order to clear up the existing state of trees. 1. Number of the main tree-crops show a nearly uniform tendency on the whole, and they show about 400 per hectare; but the distribution is ununiform state. 2. Number of the sub tree-crops are too far lack in order to supperesion by the main crown formation of the over matured uniform forests, in many another parts they are less than main tree-crops, and the distribution state is more uniform than the main tree-crops. Number of trees in middle regions are especially changeable according to change of the parts. 3. The horizontal crown density shows 10-11 on the decimal and forest type forms up over matured uniform forest on the whole, and occupational rate of the hard wood crown shows no more than 50 per cent in maximum state to the all canopy. The more increase of the large diameter of hard wood the larger in the crown density of forest. The horizontal space occupy about 7-17 per cent to the canopy, and they are almost found here and there. 4. We find that there are 50-60 per cent of the healtly trees, 30-40 per cent of the inferior trees and 5-20 per cent of the blighted trees to the all standing trees, these result relate that there are a large number of the inferior trees and blighted trees in the inaccessible forest. The dead top-end trees are over 40 per cent of the inferior trees, this result relate that the forest trees are over maturing and sinking. We found plenty of heart decay in Tsuga diversifolia Mast. and Chamaecyparis pisifera Siev. et Zucc. 5. The existing state of seedlings is more ununiform than the upper trees, but number of existing trees show only 1000; the condition of reproduction after upper trees cutting is standing a very disagreeable situation. From the state of existance trees and generation point of view, we recognized that Abies homolepis Sieb. et Zucc. dominant in the lower regions, Tsuga diversifolir Mast. and Abies Veitchii Lindl. in the upper regions and Picea jezoensis ver. hondoensis Rehd. in the middle regions. 6. The dead standing trees occupied 20-40 per cent to the existing trees are a feature in this area. The large or middle diameter trees are generally due to over matured and the dead small diameter trees or over sub tree-crops are due to intense suppreseed, injury by the fallen trees and transition of the environment. C. On the structure of stand age. According to the result of investigation of age structure, in general the range of age highly, widely and unorderly because of suppresed age is differenced from state and forest condition, therefore the term of suppresed age extends to one or two through young to old tree age. But as there are limit in height growth, most of crown come to structure the uniform or the two-storied forest. These old-age uniform forest are so changeable that if there are given rapid thinning, authors forecast that the peculiar species will be alternated by other species, and that there is the bound of possibility of species alternation by hard wood in this case.
信州大学農学部の論文
1956-03-30

高山林の施業に関する研究(第1報)林分構造並びに年齢構成について

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