Summary. Photosynthetic performance of Norway spruceneedles [Picea abies (L.) Karst.] was measured over a 1-year period. The trees grew in an area of heavy air pollution and forest decline on a mountain ridge in the eastern Ore Mountains (Czech Republic). Photosynthetic capacity, as well as light use efficiency, decreased dramatically with time, starting in July (2 months after bud-break) to finally reach zero (respiration only) by February of the following year. Two months later all needles from upper crown parts were shed. Needles from lower crown parts, on the other hand, were undamaged. The chlorophyll and Mg content decreased transiently during the cold season, with Mg reaching deficiency thresholds during winter. However, total sulfur, as well as organic and sulfate S increased with time. The increase was higher in needles from the upper parts of the crown, which were exposed to windy air throughout the year, than in the lower parts of the crown, which were covered by grass during summer and by snow during most of the winter.
ABSTRACT:The present paper evaluates the height, diameter and stem volume of parental tree progenies. These Norway spruce progenies are compared with the control estimated from tables. The control was overperformed in all measured growth parameters. Heights of selected spruce progenies at the age of 26 years ranged from 9.2 m (K10) to 10.7 m (K2). The control height was 6.4 m. In the evaluation of diameters, progeny K4 showed the best mean dbh (13.7 cm) while the progeny K17 was rated as the thinnest (10.5 cm). We compared these data with the control diameter of 6.5 cm. The mean volumes of selected material varied from 0.097 m 3 (K9) to 0.047 m 3 (K17) while the control presented 0.0172 m 3 .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.