Naslov
Effect of rounding number of stems per diameter classes on stand volume

Autori
Božić, Mario ; Vedriš, Mislav ; Goršić, Ernest ; Carić, Mato

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of 45th international symposium on forestry mechanization “Forest engineering: Concern, Knowledge and accountability in today’s environment” / Pentek, Tibor ; Poršinsky, Tomislav ; Šporčić, Mario - Zagreb : Šumarski fakultet Sveučilišta u Zagrebu, 2012, 1-9

ISBN
978-953-292-025-3

Skup
45th international symposium on forestry mechanization “Forest engineering: Concern, Knowledge and accountability in today’s environment”

Mjesto i datum
Cavtat, Hrvatska; Dubrovnik, Hrvatska, 08.10.2012. - 12.10.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
forest inventory; number of stems; rounding off; stand volume

Sažetak
Forest stand structure is the basis for forest planning in Croatia. Most of the stand structure data are obtained by sample plot measurements. For every dominant tree species number of trees per diameter class is calculated as a number of trees per hectare both on the single plot or the stand level. Number of trees per diameter classes is displayed as whole (rounded) number in Management plans. When calculating total stand volume, two approaches are used. Most of the forest planners used raw (not rounded) data in calculation, while displaying rounded number of trees per hectare and only some of them used rounded number of trees for calculation as it is written in Management plans. This paper presents the effect of rounding the tree number (whole number, one decimal and two decimal places) on total volume calculation in two different Management units: ''Opeke'' and ''Sungerski lug''. Total volume in Management unit “Opeke” (even-aged stands) is higher if the tree number is rounded to whole number in comparison with volume calculated when the tree number per ha used for calculation is rounded to one or two decimal places. Volume calculated by whole number compared to the volume calculated from rounding to one or two decimal place is 0, 75 % and 0, 91 % higher, respectively. On a stand level volume differences vary from -3, 2 to +5, 1 % and -3, 6 to +6, 1 % respectively. Total volume in Management unit ''Sungerski lug'' (uneven-aged selection stands) is lower if the number of stems is rounded to whole number compared to the volume calculated when tree number per hectare used for calculation is rounded to one or two decimal places. In this case volume calculated by whole (rounded) number of trees compared to one or two decimal place rounding is -0, 70 and -0, 73 % lower, respectively. On stand level volume deviation varies from -6, 4 to +6, 4 % and from -6, 5 to +7, 2 %, respectively.

Izvorni jezik
Engleski

Znanstvena područja
Šumarstvo

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