tailieunhanh - Báo cáo lâm nghiệp: "Quality of wood in the stands of poplar clones"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Quality of wood in the stands of poplar clones. | JOURNAL OF FOREST SCIENCE 54 2008 1 9-16 Quality of wood in the stands of poplar clones R. Petrás J. Mecko V. Nociar National Forest Centre - Forest Research Institute in Zvolen Zvolen Slovakia ABSTRACT The results obtained in research on the quality of raw timber by means of the structure of assortments for the stands of poplar clones Robusta and I-214 are presented in the paper. Models for an estimation of the structure of basic assortments of poplar stands were constructed separately for each clone in dependence on mean diameter quality of stems and damage to stems in the stand. The clone Robusta has higher proportions of higher-quality assortments than the clone I-214. The accuracy of models was determined on empirical material. It was confirmed by statistical tests that the models did not have a systematic error. The relative root mean-square error for main assortments of the clone I-214 is 15-27 and Robusta 13-24 . Keywords poplar clones wood quality assortment structure In wood production not only the quantity is important but also the quality of wood is of increasingly growing importance. Higher-quality wood has the higher utility value and price. Relatively great attention is paid to these issues in Slovakia. In the past models of tree and stand assortment tables were constructed for 8 commercially important tree species namely for spruce fir pine oak and beech Petras Nociar 1990 1991 and for larch hornbeam and birch Mecko et al. 1993 . Together with the models of yield tables Halaj et al. 1987 Halaj Petras 1998 they were also used for the construction of assortment yield tables Petras et al. 1996 and together with the prices of wood and costs of wood logging also for the construction of the models of value production Halaj et al. 1990 . After a short break research on the production of poplar clones Robusta and I-214 continued Petras and Mecko 2001 2005 elaborated the volume production of these clones in the form of models of yield tables. The research of