The need to improve control of cone rust epidemics led us to investigate seasonal fruiting and sporulation of cone rusts in Norway spruce ( Picea abies (L.) Karst.) cones and alternate hosts in 2006–2008. Spermogonia of Chrysomyxa pirolata Wint. and aecia of Thekopsora areolata (Fr.) Magnus developed in current-year cones in June, whereas C. pirolata aecia developed and started to sporulate in July. Thekopsora areolata aecia sporulated mainly in previous-year cones in May–August. Uredinia, telia, and basidia of C. pirolata developed in overwintered Pyrola sp. and Orthilia secunda L. leaves in May and sporulated in May–June. Uredinia of T. areolata developed in current-year Prunus padus L. leaves in June and sporulated in June–August. Telia of T. areolata developed in late summer, but no basidia were observed in overwintered Prunus padus leaves in March–May. Only minor variation occurred at the time of fruiting and sporulation of cone rusts both among cones and leaves of alternate hosts. Periods of high daily rainfall in May coincided with the epidemic peaks during female flowering in 2006. Dry periods in May coincided with high C. pirolata uredinia and low telia production on alternate hosts. However, monthly rainfall during pollination did not explain the epidemic rust patterns in cones. Timing of disease control is discussed.

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Patterns of height increment and ramification in Betulapubescens Ehrh. of sprout and seed origin were studied at Kannus (63°53′ N) during the first few growing seasons, 1982–1985, employing trees of various ages (0–15 years). Sprouts developed very much more rapidly than seedlings during the first three seasons, as a consequence of the free growth pattern and associated pronounced growth flushes. Their annual height increment declined somewhat after a few years, however, whereas that of trees of seed origin remained constant or increased slightly. The mode of height growth in birches over 10 years of age appeared to approach the short-duration growth model. Branches of sprouts also grew more than those of seedlings, in the first few growing seasons, with distinct differences in branching pattern visible between the two tree forms, and also between sprouts originating from buds located above and below ground. Young sprouts used practically all buds to form branches and short shoots, giving them a bush-like appearance. In contrast, most axillary buds on seedlings remained dormant and the individuals adopted an arboreal mode of growth at an early stage. The less branched appearance of older trees of seed origin was also due in part to the death of a higher proportion of buds and branches.

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Mechanical harvesting of peatlands completely changes the original bog ecosystem and without afteruse causes long-lasting disturbance in the environment due to the limited restoration capacity of the habitat. We studied the effects of fertilization on the establishment of vegetation on a cut-away peatland in Finland. Six treatments of different quantities and mixtures of wood ash, peat ash, biotite, or forest P–K fertilizer were replicated in three plots. Although all the fertilizers accelerated the revegetation of a cut-away peatland significantly, ash-based fertilizers had the greatest and most immediate impact on the formation of vegetation. Ash fertilizers especially increased the coverage of small fire-loving moss species such as Ceratodon purpureus (Hedw.) Brid., Funaria hygrometrica Hedw., and Leptobryum pyriforme (Hedw.) Wils. in the early stages of the succession. Furthermore, the succeeding coverage of vascular plants improves nutritional conditions through the rapid accumulation and decomposition of plant-derived litter. The rapid formation of ground vegetation on bare peat surface after ash fertilizer application indicated that wood and peat ash are suitable for mined peatlands. This being the case, peat and wood ash should be regarded more as a recyclable constituent rather than as waste in afforestation of cut-away peatlands.

Seasonal fruiting and sporulation of cone rusts were investigated in Norway spruce cones during the growing season of 2007, a year after an excellent cone crop and a severe outbreak of rust. Current-year and 1-year-old cones were collected bimonthly to monthly from case-stands in southern and northern Finland and checked for rust fruitbodies. A previously unreported species of rust formed spermogonia and aecia, and sporulated on the cone scales of Norway spruce in two study areas. Morphologically, the rust was distinct from other spruce cone rusts and, based on ultrastructure of aecia and aeciospores, most closely resembled Chrysomyxa ledi. Molecular analysis of the aeciospores confirmed that the rust belonged to the C. ledi/C. rhododendri complex. The rust fruited frequently but only colonized a few scales per cone and presumably had a minor effect on cone development and seed crop.