tailieunhanh - Báo cáo khoa học: " Intraspecific variation of growth and adaptive traits in European oak species"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Intraspecific variation of growth and adaptive traits in European oak species. | 166s Ann Sci For 1993 50 Suppl 1 166S-185S Elsevier INRA Review article Intraspecific variation of growth and adaptive traits in European oak species J Kleinschmit Lower Saxony Forest Research Institute Department of Forest Tree Breeding W-3513 Staufenberg OT Escherode Germany Summary According to various reports 200-450 oak species including hybrid populations exist worldwide with 24 of these - including 3 hybrid forms - having their natural range within Europe. They all belong to the subgenus Lepidobalanus. The most important section is robur with 21 species. The European species belong to both deciduous 15 species and evergreen 9 species oaks. Some difficulties in clear morphological and physiological definition of the species involved is caused by hybridization. Most studies into intraspecific variation exist for the species Quercus robur L and Quercus petraea Matt Liebl. Some information is available for Quercus cerris L Ouercus virginiana Ten Q dalechampii Wenz Quercus ilex L and Quercus Suber L based on comparative plantations. In addition a considerable number of morphological physiological and biochemical studies based on natural populations exist which are not completely covered in this review paper. For most characters observed oaks exhibit a wide variation. This is not only the case for morphological traits of pollen seed wood and plants but also for physiological traits and phenology which have great adaptive importance. Provenance experiments and progeny tests started as early as 1877. Most of these were only of local importance. This is partly due to the fact that acorns can only be stored for a limited period and flowering is irregular. However the results available show that the choice of provenance can be important for the successful economic management of plantations. Variability of leaves phenology form growth wood and bark roots seed and flowering has been discussed separately. Improvement via selection and testing seems to be promising due to