Prethodno priopćenje
Time consumptions of field measurements intended for assessment of assortment structure of beech cut blocks
Marinko Prka
Tomislav Poršinsky
Sažetak
Within comprehensive research of assortment structure of beech cut blocks of even-aged forests, records were also made of time consumptions required for carrying out field measurements of 2,308 beech trees obtained as a result of thinnings and shelterwood cuttings. Sample trees were processed in accordance with the requirements of the Croatian standards related to products of forest harvesting of 1995 (HRN), and the same trees were used for carrying out »bucking simulation« in accordance with the European Standard EN 1316–1:1997, i.e. in accordance with its Croatian variant, with the status of the Croatian Standard (HRN–EN). A sample consisting of 787 trees was made in thinning operations. 788 trees were measured in preparatory cuts, 467 in seeding cuts and 266 in final cuts. The research goal was to establish possible dynamics of carrying our field measurements (time consumptions required for measuring sample trees by type of cut, average tree diameter and way of processing stackwood), which is a considerable contribution to planning and performing future researches of assortment structure of individual species of trees. The research showed that the average time required for felling, processing and measuring sample trees increases from thinning to final cuts. Time consumption of processing and measuring sample trees is most strongly influenced by the way of processing stackwood, i.e. processing of fuelwood ranging in length from one to several metres. In carrying out these researches, the cutters’ productivity was lower by approximately 20 to 30 % compared to their regular production process. Such researches can be carried out simultaneously with the regular process of timber production, and by optimisation of the number and content of sample trees suitable for field measurement (technical staff and cutters) its efficiency may be affected depending on the features of the researched felling site. Field measurements, whose aim is the preparation of assortment tables applicable in practice in accordance with the requirements of a specific standard, can be carried out with lower average time consumptions per sample tree than determined in this research. Consequently, although relatively large groups of sample trees are required for such researches, they can also be carried out with not as high time consumptions and research costs, and hence it can be concluded that actually there are no obstacles for the forestry science and practice to solve satisfactorily the problem of wood assortment structure of the main tree species.
Ključne riječi
assortment structure; field measurements; time consumptions; common beech
Hrčak ID:
10034
URI
Datum izdavanja:
28.12.2006.
Posjeta: 1.160 *