Avtor/Urednik		Trošt, Tadeja; Gaberščik, Alenka
Naslov		Effects of enhanced uv-b radiation on Norway spruce (Picea abies) activity and production of protective compounds
Tip		članek
Vir		In: Hasenauer H, editor. Proceedings of the international conference Forest ecosystem restoration: ecological and economical impact of restoration processes in secondary coniferous forests; 2000 Apr 10-12; Vienna. Wien: Institute of forest growth research,
Leto izdaje		2000
Obseg		str. 271-6
Jezik		eng
Abstrakt		Some researches suggested that conifers were quite tolerant to enhanced UV-B radiation. The present study evaluated the effects of increased UV-B radiation on Norway spruce seedlings (Picea abies (L.) Karst.). Plants were exposed to three different levels of UV-B, to reduced UV-B, ambient UV-B plus additional UV-A and ambient UV-B plus additional UV-A and UV-B. Once a month the following parameters were monitored: light saturated photosynthetic activity, light saturated photochemical efficiency: Fv/Fm, Y, NPQ, potential respiration, total chlorophyil content and chlorophyll a/b ratio and methanol soluble UV-B absorbing compounds. The germination experiment was conducted in April, the plants from a subalpine stand were tested in July. The experiment proved that Norway spruce was quite tolerant to enhanced UV-B radiation. The protective mechanisms appeared to be dependent on the developmental state of leaf more than induced by enhanced UV-B radiation. The complex interaction of numerous stress factors in the subalpine stand mainly affected the activity of young needles, but seemed to stimulate faster senescence process.
Deskriptorji		TREES ULTRAVIOLET RAYS PHOTOSYNTHESIS GERMINATION