S L' M M .\ R •^'Variations ol'terpenc, resin acid and total phenolic concentrutions in yuung seedlings of SiicitF. pine (Pinus sy L,) from nine different seed origins growing in three locations of different latitudes, in Finland and Kstonia, wert investigated in autumn 1991 and spring 1992. Seasonal variation uas remarkahle in monoterpene, resin acid and total phenolic concentrations. In spring there was more 3-carene, a-pinene, /^-pinene + sabinene and total monoterpenes m pine shoots, and less myrcene and tncyclerie compared to autumn. Concentrations of some individual resin acids, levopimaric and dehydroahietic acids, were higher in autumn. The total phenolic concentration vvas higher in spring. In the most northern location, the concentrations of total monoterpenes and total phenolics were lowest. The total resin acid concentration vvas highest in the middle location, and indi\idual resin acids, palustric and neoabietic acids, w ere more common in the most northern location. Seed origin had no significant effects either to the resin acid or total phenolic concentrations. There wt're almost equal concentrations of total phenolics and resin acids in northern and southern t)rigins. Instead some individual monoterpenes. limonene, tricyclene, camphene, /f-pinene + sabinene and hornylacetate, were more common in northern seed origins. The results suggest that the origin of the seed material is not so important in affecting the concentrations of secondary compounds as are the en\ ironmental factors.

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Needle retention in conifers is affected by several environmental factors, e.g. climate, mineral nutrition, other edaphic conditions, and more recently by air pollution. This paper describes a method to determine the history of needle retention in pine stems. In the pines so far investigated, the retention of needles varied from one to four annual needle sets (year classes); and there were significant differences in the variation of retention between individual trees. No descending trend was detected which could have been caused by adverse changes in the environment. Some years with deep troughs in the retention data could be connected with exceptionally cold vegetative periods.

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Three species of Melampsoridium have been reported to infect hosts in genus Alnus. An epidemic of foliar rust affecting A. glutinosa and A. incana began in Europe in the mid-1990s, and the associated pathogen was identified as Melampsoridium hiratsukanum based on morphology. In this investigation we analyzed the morphology and genetic variation of alder rusts from Europe and Japan and the host specificity of the European epidemic rust. Our results showed that two rusts occur on the leaves of alders native to northern Europe; in Scotland an endemic rust indistinguishable from M. betulinum occurs, whereas alders in areas of Europe affected by the current epidemic were infected by M. hiratsukanum. M. hiratsukanum from naturally infected alder in Finland produced aecia on all Larix species tested but did not infect Betula leaves.