Silva Fennica vol. 18 no. 1 | 1984

A literature survey based on Nordic literature deals with the biology, use, harvesting and economy of birch (Betula sp.). According to the results, the easily quantified hard facts are against cultivation of birch: lower growth, poorer production of valuable assortments, lower price of pulp, higher planting costs, and higher harvesting and transport costs than for conifers. The soft facts, which may be true, are not easily measured or their importance evaluated: the possible improvement of soil, decreasing risk of insect and fungi attacks, shelter against frost etc. Due to the differences in the nature of the facts the discussion of cultivation of birch will probably continue.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The Lauhavuori area is barren, consisting of sandstone and granite bedrock covered by coarse moraine and sand. The woodlands are dominated by Scots pine (Pinus sylvestris L.) and Calluna. The top of the hill, rising 230 metres above the sea level, is more fertile, as it was never covered by the ancient Baltic Sea. Numerous springs and spring brooks are bordered by herb-rich Norway spruce (Picea abies (L.) H. Karst.) woodlands and swamps. Although most of the peatlands are oligotrophic, several mesotrophic peatland plants occur, some southern, giving the peatlands a rather northerly character.

The study area is 8 by 12 km. According to the vegetation analysis, 310 species were identified, 208 of which were native to the area and 102 immigrants. The native species can be separated from the immigrants because the area is largely undisturbed.

The PDF includes a summary in English.

• Suominen, E-mail: js@mm.unknown
• Varkki, E-mail: av@mm.unknown

Harvest index and number of associated traits were measured in a 16-year-old Scots pine (Pinus sylvestris L.) progeny test based on full-sib families. It was found that harvest index is a highly heritable trait and that a number of yield components are positively correlated with it. It is suggested that harvest index and tree ideotypes should be the basis of selection in cultivated trees. It is emphasized that an integrated approach to tree improvement including silviculture, soil science, industrial and economic constraints and tree breeding is a prerequisite for maximal response.

The PDF includes a summary in Finnish.

• Velling, E-mail: pv@mm.unknown
• Tigerstedt, E-mail: pt@mm.unknown

The purpose of this study was to examine the use or citations in Finnish forestry publications using source analysis. The material consisted of three of the four main series published in the field of forestry in Finland. The study was confined to three sample years in the middle of each decade during the period of 1910–1980.

The use of references in Finnish forestry sciences was abundant: from 30 to 60 references per report and from 1.1 to 1.7 references per page. The amount of self-citations varied from 6 to 9%. The half-time of the references was, in general, very long varying from 8–12 years in forest economics to 14–17 years in silviculture and forest biology. The amount of ”classical” publications was 4–11%. The amount to Finnish references was large varying from 30 to 59%. Anglo-Saxon series made 22–24%, Scandinavian 11–13%, German 7–9%, Russian 1–3% and French series less than one per cent of all references.

The PDF includes a summary in English.

• Leikola, E-mail: ml@mm.unknown