Current issue: 58(5)
Silva Fennica vol. 7 no. 4 | 1973
Category : Article
This article is a book review of a book Forest inventory by Loetsch–Zöhrer–Haller.
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Nyyssönen,
E-mail:
an@mm.unknown
The study describes the relationships between a method developed by the author for the calculation of the profitability of forest drainage and the old biological method. The calculations were based on empirical data, and they aimed at finding out the effect of a variation in the profitability limit in the areas in hectares to be drained, and on the profitability of drainage. The study deals also with the profitability of present-day drainage activities. The results showed that the profitability coefficient (the ratio between the discounted increase in returns and the costs of drainage) averages 3.04 for the whole country. The corresponding value was 5.68 for Southern Finland, 3.19 for Central Finland and 1.67 for Northern Finland.
The PDF includes a summary in English.
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Heikurainen,
E-mail:
lh@mm.unknown
As a subproblem in the joint Nordic Terrain-Machine Project the requirements set by forest road construction on the terrain classifications were studied during the summer 1973 in ten operations, in which either a bulldozer or an excavator method was used.
The most important terrain factors of the ground factors affecting the construction time of the road base were the so-called depth index and the moisture content of the soil, and in addition to these the amount of stumps as a ground roughness factor. These variables explained, however, only a rather minor part of the wide variation in the construction output of the practical operations.
The PDF includes a summary in English.
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Haarlaa,
E-mail:
rh@mm.unknown
The aim of the study was to assess, through field experiments, the possibilities of using peat briquettes in the seeding of Scots pine (Pinus sylvestris L.) in Southern Finland. The briquettes were dug into the soil in the middle of patches of mineral soil. The seeds were covered by a 2-5 mm layer of mineral soil. The seedings were inventoried in the three following autumns.
According to the results, the briquettes were clearly inferior to the control, which was ordinary drill seeding. This was mainly due to the fact that no rain was received after the seeding, and that the third summer from seeding was extremely dry. Abundant germination was observed during the second summer after seeding in both briquette seeding and the control. During more rainy summers the result might have been better.
The PDF includes a summary in English.
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Lehtiniemi,
E-mail:
tl@mm.unknown
Photosynthesis and dark respiration in five families of autochtonous Norway spruce (Picea abies (L.) H. Karst.) and in seedlings from twenty Finnish stands of Scots pine (Pinus sylvestris L.) were investigated in constant environmental conditions. Values of CO2 exchange were compared with the height growth and weight of seedlings in Norway spruce and with the weight alone in Scots pine. No statistically significant differences were found in CO2 exchange among progenies or stands. Photosynthetic efficiency and photosynthetic capacity showed a positive correlation both in spruce and in pine. Growth and net photosynthetic capacity were linearly and positively correlated in pine. Spruce and a higher light compensation point than pine. The use of an open IRGA system with several simultaneous measurements and the trap-type cuvette construction in genetic work are discussed.
The PDF includes a summary in English.
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Luukkanen,
E-mail:
ol@mm.unknown
