DIGITALNA ARHIVA ŠUMARSKOG LISTA
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 ŠUMARSKI LIST 1-2/1958 str. 22     <-- 22 -->        PDF [3]Lötsch F., Das Tarifdifferenzverfahren zur Massenzuwachsermittlung, Schweiz.Z. Fortsw. 1954.[4] Prodan M., Messung der Waldbestände, 1951.[5] KlepacD., O Šumskoj proizvodnji u fakultetskoj šumariji Zalesini, Glasnik zašumske pokuse, br. 11, 1953.[6] Klepac D., Komparativna istraživanja debljinskog, visinskog i volumnog prirastau fitocenozi jele i rebrače, Sum. list, br. 2/3, 1954.[7] KlepacD., Istraživanje debljinskog prirasta jele u najraširenijim fitocenozamaGorskog Kotara, Glasnik za šumske pokuse, br. 12, 1956.18] Tischendorf W., Die Genauigkeit von Messungsmethoden und Messungsergebnissen,Forstwiss. Cbl., 1925.[9]Levaković A., K pitanju raspoređivanja primjernih stabala među pojedine debljinskeskupine, Glasnik za šumske pokuse, broj 3, 1931.SUMMARYThe volume increment is equal to the product of diameter increment and slopeof tariff line [see equation (1)]. An erroneously selected tariff will yield an error ofsystematic character. Therefore the random error of volume inerement will dependon the slope of the tariff line, the number of cores and the standard deviation ofdiameter increment. This standard deviation (o2X) — in all diameter classes arisingin practice — is constant in a given stand, and independent of the aize of d. b. h.This was presumed in the papers of Meyer [1] and Loetsch [2] [3] without any proof.Here we have proved it on the material collected by Klepac [5] (see Table 1). On thesupposition that 2X is linearly dependent on d. b. h. [see equation (6)], the parameterb should be significantly different from zero, which actually is not the case (seeTable 2). Consequently, the error of the total stand volume increment is given byequation (8), and it will be minimum, if the increment cores are distributed withinthe diameter classes according to equation (14). The deduction [of eqations (9) — (14)Jis similar to that used by Tischendorf [9]. On the supposition that the tariff line hasthe equation (15), the proportion in equation (14) assumes the formPi : P2 : P3 : "" nj: xi: n2 X2 : ns xs :(py — number of cores in the ith — diameter class,n; = number of stems in the i´1 — diameter class,x: = average diameter in the i´* — class)In this case maximum accuracy (i. e. minimum error) for a definite number ofcores will be attained.