tailieunhanh - Báo cáo lâm nghiệp: "Variation of the tree form factor and taper in European larch of Polish provenances tested under conditions of the Beskid Sądecki mountain range (southern Poland)"

Tham khảo luận văn - đề án 'báo cáo lâm nghiệp: "variation of the tree form factor and taper in european larch of polish provenances tested under conditions of the beskid sądecki mountain range (southern poland)"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | JOURNAL OF FOREST SCIENCE 53 2007 12 538-547 Variation of the tree form factor and taper in European larch of Polish provenances tested under conditions of the Beskid Sạdecki mountain range southern Poland J. Socha1 M. Kulej2 -Department of Forest Mensuration Faculty of Forestry Agricultural University of Cracow Poland Department of Forest Tree Breeding Faculty of Forestry Agricultural University of Cracow Poland ABSTRACT The genetic variation in 20 provenances of European larch growing under site conditions of the Beskid Sạdecki mountain range experimental area in Krynica was investigated during a long-term study carried out within the 1967 Polish Provenance Experiment on Larch. Data consisted of diameter measurements taken outside bark on standing trees of the analyzed provenances. Results showed that there was no distinct variation in the tested larch populations in respect of stem form. Some differences between compared provenances in respect of stem taper and form factor were the result of differences in tree height and diameter. Keywords genotype planting experiment stem profile The determination of the volume of trees and their parts by means of the basic characteristics such as dbh and height recommended from the practical point of view is burdened with errors resulting from variation of the stem form of trees. This variation is a result of differences in the rate of diameter increment at different heights of the stem and differences in the height increment of trees Mitscherlich 1970 . These differences may be caused by many factors including species variation climatic factors site quality age of trees and stands defoliation and stand density Muhairwe 1994 . The taper of the upper stem section is also affected by the length of the crown Kilkki Varmola 1981 Larson 1963 Socha 2002 . Within the crown stem diameters at particular heights are generally smaller in comparison with trees of the same dimensions but shorter crowns. Also genetic factors may decide on