DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 9-10/2018 str. 53 <-- 53 --> PDF |
hereafter - u.b.). According to the data shown, the bark volume for all of the harvested wood can be estimated at 32,053 m3. Removal intensity is often related to the extraction types and the cut-block area. It varied largely between 0.2 and 962.4 m3 o.b. × ha-1 (0.2 and 917.2 m3 u.b. × ha-1) as being specific to low extractions (SAN) or high intensity extractions (clear cuts - CF, selective cuts - SEL) and it averaged 97.3 m3 o.b. × ha-1 (92.4 m3 u.b. × ha-1). Tree size varied also widely from less than 0.1 to more than 5.0 m3 × tree-1, as in the area exist some old-grown beech forests. Even if a wide range of forests were taken into account, including plain and hilly forests, the average terrain slope was of almost 24°. Notable was also the extraction distance which averaged more than 1,1 km, varying widely between 200 m and 3 km. Clear fells (CF) accounted for less of 1% both in terms of sold (extracted) volume and harvested areas (Fig. 2). Predominant in the harvested volume were the selective removals (SEL) while the thinning operations (THI) accounted for near the same share in terms of harvested area and volume. As expected, the sanitary extractions (SAN) contributed more in the harvested area and less in the harvested volume. The share of harvesting systems used to extract the wood was computed based on the number of contracts in which a given harvesting system was effectively used (not shown herein). Motor-manual tree felling and processing followed by skidding using winch skidders or adapted farm tractors (MMF-SKID) accounted for 89.18% of the cases being used to harvest the wood corresponding to 1063 carried-on harvesting contracts. The next in line was the motor-manual tree felling and processing followed by animal powered logging (MMF-AL) with a share of 10.32% (123 cases). Cable yarding was used for less than 1% of the cases (6 cases). 3.2. Regression models of the tendering prices – Regresijski model natječajnih cijena Regression analysis returned the models included in Equations 1 and 2. Following the correlation analysis both, the sold volume per cut-block (m3 u.b.) and removal intensity |