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Now showing items 1847-1866 of 1932
  • Aro, Paavo (Suomen metsätieteellinen seura, 1949)
  • Saari, Eino (Suomen metsätieteellinen seura, 1954)
  • Jentsch, Fr. (Suomen metsätieteellinen seura, 1929)
  • Aaltonen, V. T. (Suomen metsätieteellinen seura, 1920)
  • Cajander, A. K. (Suomen metsätieteellinen seura, 1923)
  • Heiskanen, Juha-Pekka (Suomen metsätieteellinen seura, 1993)
  • Siipilehto, Jouni; Lyly, Olavi (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1995)
    The following treatments were compared in three Scots pine (Pinus sylvestris L.) reforestation areas on a scarified moist mineral-soil site in southern Finland, planted with 1+1 bareroot stock in spring 1987: (a) no weed control treatment; (b) mulching with a fibre slurry produced by mixing wastepaper with water and applied 1 cm deep to an area 60 cm in diameter around the seedling soon after planting; (c) glyphosate (at 2 kg ha–1 a.i.) sprayed on a 1 m2 spot around the seedling in early August 1987; (d) terbuthylazine (at 10 kg ha–1 a.i.) applied as (c). Monitoring of the trials over a 4-year period between 1987–90 showed that none of the treatments reduced surface vegetation to an extent that would have benefited pine. The percentage cover development of the vegetation, dominated by Agrostis capillaris, Calamagrostis arundinacea, Deschampsia flexuosa, Festuca ovina, Epilobium angustifolium and Pteridium aquilinum, followed much the same pattern in all treatments, with (c) slightly favouring forbs. Survival of pine at the end of the study period was about 90%, with non-significant differences between treatments. Mulching and terbuthylazine treatment slightly reduced seedling height growth in the second year. Growth was better in glyphosate treatment than in terbuthylazine treatment in the lowest (< 30%) and the highest (> 60%) pre-treatment weed cover classes and in the latter also better than in untreated control. Mulching gave variable results; at its best it provided good control of weeds for several years, without, however, improving the initial development of pine in these trials.
  • Kilkki, Pekka; Päivinen, Risto (Suomen metsätieteellinen seura, 1986)
  • Cajander, A. K. (Suomen metsätieteellinen seura, 1930)
  • Lukkala, Oskari Jalmari (Suomen metsätieteellinen seura, 1927)
    Mitä näkökohtia on otettava huomioon ojitettaessa vesiperäisiä maita metsänkasvua varten.
  • Salo, Leo J. (Suomen metsätieteellinen seura, 1974)
  • Långström, Bo (Suomen metsätieteellinen seura, 1984)
  • Saari, Lennart; Nuorteva, Matti (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1996)
    In the winter of 1977/78, a White-backed Woodpecker was observed in the archipelago of southwestern Finland 200 km from its breeding areas. It foraged on insects living in small dead alders and birches. The potential prey species were identified by rearing the insects from the trunks used by the White-backed Woodpecker. Altogether 628 adult insects emerged. In addition to the big larvae the potential food also included larvae of Sciaridae and Cecidomyidae (Diptera) living in dense clumps.
  • Haapanen, Matti (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1995)
    Tree height data from 33 progeny trials of Scots pine (Pinus sylvestris L.) were used to determine the effect of within-plot subsampling on the magnitude of statistically detectable differences between families, family heritability and correlation of family means based on different sample sizes. The results indicated that, in trials established with a standard plot configuration of 25 trees per plot, measuring only 10–15 trees gives nearly the same precision as with assessment of all the plot trees. Even as few as 4–6 trees assessed per plot may constitute a sufficient sample if families or parental trees of extreme performance are being selected. Trials established with non-contiguous plots were found to be more efficient than those established using multiple-tree contiguous plots.
  • Bhat, K. M.; Kärkkäinen, Matti (Suomen metsätieteellinen seura, 1982)
  • Bhat, K. M.; Kärkkäinen, Matti (Suomen metsätieteellinen seura, 1981)
  • Tyrväinen, Jukka (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1995)
    In the first part of the study, the selected wood and fiber properties were investigated in terms of their occurrence and variation in wood, as well as their relevance from the perspective of thermomechanical pulping process and related end-products. It was concluded that the most important factors were the fiber dimensions, juvenile wood content, and in some cases, the content of heartwood being associated with extremely dry wood with low permeability in spruce. With respect to the above properties, the following three pulpwood assortments of which pulping potential was assumed to vary were formed: wood from regeneration cuttings, first-thinnings wood, and sawmill chips. In the experimental part of the study the average wood and fiber characteristics and their variation were determined for each raw material group prior to pulping. Subsequently, each assortment - equaling about 1500 m3 roundwood - was pulped separately for a 24 h period, at constant process conditions. The properties of obtained newsgrade thermomechanical pulps were then determined. Thermomechanical pulping (TMP) from sawmill chips had the highest proportion of long fibers, smallest proportion of fines, and had generally the coarsest and longest fibers. TMP from first-thinnings wood was just the opposite, whereas that from regeneration cuttings fell in between the above two extremes. High proportion of dry heartwood in wood originating from regeneration cuttings produced a slightly elevated shives content. However, no differences were found in pulp specific energy consumption. The obtained pulp tear index was clearly best in TMP made from sawmill chips and poorest in pulp from first-thinnings wood, which had generally inferior strength properties. No dramatical differences in any of the strength properties were found between pulp from sawmill residual wood and regeneration cuttings. Pulp optical properties were superior in TMP from first-thinnings. Unexpectedly, no noticeable differences, which could be explained with fiber morphology, were found in sheet density, bulk, air permeance or roughness between the three pulps. The most important wood quality factors in this study were the fiber length, fiber cross-sectional dimensions and percentage juvenile wood. Differences found in the quality of TMP manufactured from the above spruce assortments suggest that they could be segregated and pulped separately to obtain specific product characteristics, i.e., for instance tailor-made end-products, and to minimize unnecessary variation in the raw material quality, and hence, pulp quality.
  • Vehkamäki, Seppo (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1990)
    The structure of the woodlot market in Finland in the early 1980s is described by analysing the area of woodlots sold, the heterogeneity of the woodlots, institutional regulation of woodlot ownership and information concerning the market. The decision-making processes of both woodlot sellers and buyers are examined using a model. Woodlot unit price is explained using a woodlot transaction sample for 1983 and 1984.
  • Rummukainen, Arto; Alanne, Heikki; Mikkonen, Esko (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1995)
    Linear optimization model was used to calculate seven wood procurement scenarios for years 1990, 2000 and 2010. Productivity and cost functions for seven cutting, five terrain transport, three long distance transport and various work supervision and scaling methods were calculated from available work study reports. All method's base on Nordic cut to length system. Finland was divided in three parts for description of harvesting conditions. Twenty imaginary wood processing points and their wood procurement areas were created for these areas. The procurement systems, which consist of the harvesting conditions and work productivity functions, were described as a simulation model. In the LP-model the wood procurement system has to fulfil the volume and wood assortment requirements of processing points by minimizing the procurement cost. The model consists of 862 variables and 560 restrictions. Results show that it is economical to increase the mechanical work in harvesting. Cost increment alternatives effect only little on profitability of manual work. The areas of later thinnings and seed tree- and shelter wood cuttings increase on cost of first thinnings. In mechanized work one method, 10-tonne one grip harvester and forwarder, is gaining advantage among other methods. Working hours of forwarder are decreasing opposite to the harvester. There is only little need to increase the number of harvesters and trucks or their drivers from today's level. Quite large fluctuations in level of procurement and cost can be handled by constant number of machines, by alternating the number of season workers and by driving machines in two shifts. It is possible, if some environmental problems of large scale summer time harvesting can be solved.
  • Ryynänen, Martti (Suomen metsätieteellinen seura, 1980)