Tham khảo luận văn - đề án 'báo cáo lâm nghiệp: "assimilation apparatus variability of beech transplants grown in variable light conditions of blue spruce shelter o. špulák"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | JOURNAL OF FOREST SCIENCE 54 2008 11 491-496 Assimilation apparatus variability of beech transplants grown in variable light conditions of blue spruce shelter O. Spulák Forestry and Game Management Research Institute Strnady Opocno Research Station Opocno Czech Republic ABSTRACT The paper valuates the differences in the selected characteristics of the assimilation apparatus of beech transplants growing in various light conditions of blue spruce small pole stage in the Jizerske hory Mts. in the Czech Republic. The leaf area chemical parameters and photosynthetic capacity measured by the method of chlorophyll fluorescence were established. Light conditions of individual beech trees were determined by means of processing a hemisphere photograph of the crown space. The research revealed a significant trend of decreasing nitrogen content with increasing irradiance of the beech. The foliage of the sheltered beech trees exhibited higher contents of phosphorus and potassium. The average specific leaf mass SLM of the beech under crowns was lower contrary to g dm2 in gap and the respective variants did not differ in average leaf size. A significantly higher maximum fluorescence and a maximum quantum yield contrary to in gap were found under crowns. A significant variance was also observed in the absorption capacity. It follows that the beech showed adaptation to the light conditions defined by its location within the stand of blue spruce. Keywords beech transplants light nutrient content of leaves fluorescence of chlorophyll leaf area Admission of light is one of the factors affecting the forest regeneration quantity and the growth. Apart from the yew and fir the beech is one of the tree species rather tolerant to shade. The shade tolerance is particularly important during juvenile stages because juveniles in the understorey are likely to be subject to the shade suppression Peters 1997 . Juvenile beeches can quickly adapt their leaf morphology to .