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ŠUMARSKI LIST 3-4/2019 str. 70     <-- 70 -->        PDF

For the construction of the height curves, the Richards function (Richards, 1959) was used. It served well for the obtaining the heights of the standing trees that couldn’t have been measured since they were damaged or had irregular crowns.
The volume was determined using the volumetric tables of total volume down to 3 cm for narrow-leaved ash (Pantić, 1997).
The mean and dominant quadratic diameters (dg i D100) and the Lorey’s mean and dominant height (hL  i H100) were calculated. For the presentation of the diameter and height distribution of the trees, the following numerical para­meters were used: arithmetic mean (xs), standard deviation (sd), coefficient of variation (cv%), minimum (xmin), maximum (xmax), range (r), skewness (skew) and kurtosis (kurt).
The current diameter (id), height (ih), basal area (ig) and ­volume (iv) increment of the mean tree were shown for the same, i.e. comparable collective of trees in the observed five year periods.
The differences between the current increments of different collectives of trees in the stand were tested using the t-test.
Stand structure elements – Elementi strukture sastojine
At the stand age of 75 years, 533 trees per hectare were registered with basal area of 55.92 m2·ha-1 and the volume of 791.42 m3·ha-1. The quadratic mean diameter (dg) was 35.9 cm and the diameter of dominant trees (D100) was 46.6 cm. The Lorey’s mean height was 31.2 m and the dominant height (H100) 32.7 m. Due to mortality and windthrow, the number of trees was reduced, so at the age of 80 years, 512 trees per hectare remained in the culture. At the age of 85 years, 502 trees per hectare remained in the stand, so in the observed 10-year period the number of trees was reduced by 9.2%. The current basal area and volume increment of the remained collective of trees in the period of 76-80 years of stand age was 1.04 m2·ha-1·year-1 and 18.80 m3·ha-1·year-1, while in the period of 81-85 years of stand age, it was 0.97 m2·ha-1·year-1 and 18.27 m3·ha-1·year-1.