DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 11-12/1973 str. 43 <-- 43 --> PDF |
Of the structural elements of stand the author investigated only those, which he considered that they influence mostly the natural regeneration, to wit: — horizontal projection of crowns of all trees in the stand, — horizontal projection of crowns of trees of the 1st, 2nd and 3rd storeys, — coefficient of crown cover, — multiple shaded crowns, — unshaded area in the stand, — volume of crowns of all trees in the stand, — volume of crowns of trees of the 1st, 2nd and 3rd storeys, — total basal area in the stand. As elements and indices of natural regeneration in the selection stand the author took the following ones: — total number of young reproduction and young stand of Fir, Spruce and Beech, — number of young reproduction and young stand of Fir, — number of young reproduction and young stand of Spruce, — number of young reproduction and young stand of Beech, — total number of stems of Fir, Spruce and Beech grown into young reproduction and young stand, — number of Fir stems grown into young reproduction and young stand, — number of Spruce stems grown into young reproduction and young stand, — number of stems grown up from young reproduction and young stand, — sum of total heights of young reproduction and young stand of Fir, Spruce and Beech, — sum of total heights of young reproduction and young stand of Fir, — sum of total heights of young reproduction and young stand of Spruce, — sum of total heights of young reproduction and young stand of Beech, — sum total of height increments of stems of Fir, Spruce and Beech during the 5-year period, — sum of height increments of Fir stems during the 5-year period, — sum of height increments of Spruce stems during the 5-year period, — sum of height increments of Beech stems during the 5-year period, — Performed was a correlation analysis of the elements of stand structure and those of regeneration by the method of least squares. Compared and recorded were the parameters and confidence limits in the linear regression y = A + B x, performed the variance analysis calculated and recorded the F-values. The tabular Fo.05 = 4.04 while Fo.oi = 7.19. On the basis of results obtained and presented in 192 graphs it may be asserted with certainty that there exists a strong connection and regularity between the mentioned elements of structure and the elements of regeneration. Greatest influence is exercised on the regeneration by the elements of stand structure arranged in the following order of sequence: — unshaded area, — horizontal projection of crowns, — multiple shaded crowns, — coefficients of crown cover, — volumes of crowns, — basal area. Fir, as the most skiophilous tree species of this country, endures an increased soil shading by tree crowns better than Spruce. With doubly increased soil shading, the number of Firs of the young reproduction and young stand decreases twice, while the number of Spruces decreases seven times. Highly placed crowns of trees of the 1st story of stand, also direct and difluse light, which the crowns of these trees allow to pass to the young reproduction and young stand, as well as the rich seed set of these trees are the reason why through the increased share of the horizontal projections of crowns of these trees the conditions for a natural regeneration are improved. |