Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: fumigation of Norway spruce at timberline. | 581s Ann. Sci. For. 1989 46 suppl. 581s-585s Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Ozone fumigation of Norway spruce at timberline . Havranek1 G. Wieser1 and M. Bodner2 1 Forstliche Bundesversuchsanstalt AuBenstelle fur subalpine Waldforschung Innsbruck and 2 Institut fur Botanik der Universităt Innsbruck Austria Introduction Ozone is thought to be involved in forest decline Bucher 1986 Krause et al. 1986 especially at high altitudes where increased 03 levels together with a fast increase in forest damage has been observed Berichte Tiroler Landtag 1985-1988 . Many investigations on the impact of 03 on trees have been carried out under laboratory conditions mainly with seedlings but few in the field Smidt 1978 Pye 1988 . Experimental data of effects of 03 on adult trees under field conditions are rare Coyne and Bingham 1982 or lacking altogether as for instance for the timberline region. Therefore it seemed to be of interest to fumigate an adult spruce tree with various o3 concen trations and to examine the effects of 03 on gas exchange and chlorophyll fluorescence both known to be indicators of latent or hidden o3 injury. Materials and Methods For this study a 60 yr old spruce tree Picea abies L. Karst. near the Klimahaus research station on Mt. Patscherkofel 1920 m . near Innsbruck was selected. For each treatment 6 similar twigs were enclosed in plexiglass chambers where the air was exchanged 3-4 times per minute. o3 treatments were as follows control charcoal-filtered air ambient air ambient air 38 ppb 03 1987 and 120 ppb 03 1986 respectively. The twigs were left in the fumigation chambers for one full growing season July to September . Monthly means of Table I. Monthly means of 03 concentration air temperature relative humidity and sums of precipitation at the research site on Mt. Patscherkofel. 1986 1987 o3 ppb Temp. CC . p mm 03 ppb Temp. C . p mm July 72 68 85 74 92 189 Aug. 66 68 199 62 80 129 Sept. 48
