Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Growth of hybrid poplars in silviculture at the age of 6 years. | JOURNAL OF FOREST SCIENCE 56 2010 10 451-460 Growth of hybrid poplars in silviculture at the age of 6 years L. ClZKOVA V. CizEK H. Bajajova Kunovice Research Station Forestry and Game Management Research Institute Strnady Kunovice Czech Republic ABSTRACT Growth and timber production of 28 poplar clones were evaluated. A set of clones was derived from 14 clones newly bred in Forestry and Game Management Research Institute in the Czech Republic eight well-known cultivars of Populus X euroamericana planted in Europe and imported to the Czech Republic two standard cultivars I-214 and Robusta Populus X euroamericana . Four clones of Populus deltoides were added to the test set. Tree spacing was 4 X 4 m. Stem diameter tree height and stem volume production were evaluated in 6-years-old trees. Based on the results it was concluded that the yield of four clones was higher than that of standard cultivar I-214 . Standing volume of two P. deltoides clones and one new Czech P. X euroamericana clone varied in the range of 77-121 m3-ha-1. Keywords Fluvisol Populus X euroamericana Populus deltoides timber production Poplars belong to the fastest growing trees in the temperate climate zone and have high biomass production in a relatively very short period. The yield of poplar plantations is effective despite the necessity of demanding establishment. A successful poplar culture depends on planting of proven clones good site and intensive cultural treatments. All clones usually hybrid poplars were proved in tests before their wide use in forestry or for other purposes. Clonal selection for growth rate yield pest resistance site adaptability is the main goal of breeding research programmes Stanturf et al. 2001 . Many authors investigated anatomical and physiological characteristics assuming that they have an important influence on biomass productivity. The results showed a high interclonal variability for most parameters. Strong correlations between the number of stomata on the leaf
