The structure of above-ground biomass of wild cherry (Prunus avium L.) in lowland Croatian forests

U radu su prikazane sastavnice strukture ukupne nadzemne biomase stabala divlje trešnje (Prunus avium L.) na području spačvanskog bazena u Upravi šuma Podružnica Vinkovci. Istraživanja su obavljena na 120 primjernih stabala divlje trešnje, prsnih promjera od 10 do 72 cm i visine od 10,8 do 34,4 m. Drvni sortimenti izrađeni su prema Hrvatskim normama proizvoda iskorištavanja šuma iz 1995. godine.Sortimentna struktura primjernih stabala divlje trešnje pokazuje znatna odstupanja u odnosu na tablice sortimentne strukture za voćkarice koje koristi trgovačko društvo „Hrvatske šume“ d.o.o. Zagreb. Udio trupaca za furnir kreće se od 9,29 % u debljinskom stupnju 37,5 cm do najviše 19,50 % u debljinskom stupnju 67,5 cm. Pilanski trupci prvog razreda kakvoće kreću se u rasponu od 12,04 % (72,5 cm) do 19,89 % (32,5 cm), a drugog razreda kakvoće od 17,30 % (62,5 cm) do 26,89 % (32,5 cm). Drvni sortiment tanke oblovine zastupljen je u debljinskom stupnju 17,5 cm sa 17,44 % te u debljinskom stupnju 22,5 cm sa 15,90 %, dok je u višim debljinskim stupnjevima značajno manje zastupljen. Udio prostornog drva je najveći u prvom debljinskom stupnju 88,76 % (12,5 cm) te u sljedeća dva sa 67,44 % i 47,71 %, a najmanji je u debljinskom stupnju 67,5 cm sa 27,01 %. Prosječni udio prostornoga drva iznosi 42,09 %. Otpad se u ukupnoj strukturi krupnog drva kreće od 11,24 % (12,5 cm) do 19,12 % (27,5 cm), a prosječno iznosi 16,47 %. Dvostruka debljina kore kreće se u rasponu od 0,53 cm do 3,37 cm, odnosno prosječno 1,66 ± 0,57 cm, a postotni udio kore kreće se od 4,77 % do 16,46 %, sa srednjom vrijednošću od 9,02 ± 2,01 %. Utvrđeni su i parametri Schumacher-Hallove jednadžbe, gustoća drva, udio vode, obujam granjevine (promjera <7 cm) te struktura ukupne nadzemne biomase.The paper presents the structure of the total above-ground biomass of wild cherry (Prunus avium L.) trees in the area of the Spačva basin in the Vinkovci Forest Administration. The research was performed on 120 samples of wild cherry trees with a diameter at breast height (DBH) ranging from 10 to 72 cm and tree height ranging from 10.8 to 34.4 m. Timber assortments were processed according to the Croatian Standards for Forest Exploitation Products from 1995.The assortment structure of sample wild cherry trees shows significant deviations in relation to the assortment structure tables used by the company ”Croatian Forests” Ltd. Zagreb. The share of veneer logs ranges from 9.29% (37.5 cm) to a maximum of 19.50% in the diameter class of 67.5 cm. Sawmill logs of the first quality class range from 12.04% (72.5 cm) to 19.89% (32.5 cm), and of the second quality class from 17.30% (62.5 cm) to 26, 89% (32.5 cm). Thin roundwood assortment is represented in the diameter class of 17.5 cm with 17.44% and immediately in the next with 15.90%, while in the higher diameter classes it is significantly less represented. The share of stacked wood (firewood and pulpwood) is the highest in the first diameter class, 88.76% (12.5 cm) and in the next two with 67.44% and 47.71%, and is the lowest in the diameter class 67.5 cm with share of 27.01%. The average share of stacked wood is 42.09%. Waste in the total structure ranges from 11.24 (12.5 cm) to 19.12% (27.5 cm), and is on average 16.47%. Double bark thickness ranges from 0.53 cm to 3.37 cm, with an average of 1.66 ± 0.57 cm, and the percentage of bark share ranges from 4.77% to 16.46%, with a mean value of 9.02 ± 2.01%.The parameters of the Schumacher-Hall equation, wood density, moisture content, branch volume (diameter <7 cm) and the structure of total aboveground biomass were also determined