Current issue: 58(5)
Silva Fennica vol. 7 | 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
The methodological choices of researchers are in general based on some research strategic preferences which originate from the prevailing tradition of the special research field. »Econometric» and »positivistic» approaches commit to the ideals of natural sciences whereas the hermeneutic approach represents the tradition of humanities. The explicit formulation and consideration of the philosophical and methodological commitments of the different research strategies may facilitate the discussion on the applicability of different methods of analysis.
The PDF includes a summary in English.
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Hahtola,
E-mail:
kh@mm.unknown
About one million hectares of forests are fertilized annually in Finland. The goal of the present study was to find out, by means of calculations, how the profitability of forest fertilization varies with variations in the stage of development of tree crops, the quality of the site and its geographical location. Calculations concerned bot fertilization of forests in mineral soil sites and in drained peatlands. The study is a part of a larger project concerning the order of profitability of different forest improvement measures in different conditions. The problems dealt with in this study were approached from the point of view of national economy.
On the basis of two empirical materials it is shown that there is a high correlation between the stand growth percentages before and after the fertilization. Applying the results to existing yield tables the authors calculate benefit/cost ratios showing the stage of development of the stand, the quality of the site and its geographical location. According to the results, fertilization is more profitable in sites of medium fertility than on poor sites. Profitability decreases rather fast from south to north and with decreasing timber prices.
The PDF includes a summary in English.
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Keltikangas,
E-mail:
mk@mm.unknown
- Seppälä, E-mail: ks@mm.unknown
The paper deals with the methodological problems concerning policy planning and evaluation in small woodlands. A methodological approach to effectiveness of forest policy measures calls, according to the author, for using a frame of reference formed by general economic theory and models of forest owners’ behaviour. Thus, it is important for the selection of forest policy means, and for evaluating the likely effects of a policy, to know the behaviour of the decision makers being influenced. The use of models of forest owners’ behaviour in planning forest policy is motivated by the fact that measures must often affect the woodlot through the owners’ decision making.
The PDF includes a summary in English.
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Tikkanen,
E-mail:
it@mm.unknown
The task of this study was to gather all available information concerning timber-sales behaviour of private forest owners and to try to find the probable trends in this behaviour. The initiative for the study came from the Central Association of Finnish Forest Industries.
In Finland there are areas of timber savings and those of overcutting. These are mainly explained by regional variation in prosperity of forest owners. There are also several individual factors affecting timber sales behaviour. Without major changes in forest policy the annual variation in quantity cut in Finland is increasing and the degree of cutting seem to remain below the allowable cut.
The PDF includes a summary in English.
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Hahtola,
E-mail:
kh@mm.unknown
- Järveläinen, E-mail: vj@mm.unknown
- Reunala, E-mail: ar@mm.unknown
The aim of the paper was to analyse, using a computer simulation technique, the moving distance of pulpwood bolts when direct felling of trees is used and the bolts are gathered alongside the strip road. According to the results, the average moving distance of bolts depends in a complicated way on the usable part of the stem and the spacing of strip road. As a rule, the differences between moving distances of two-meter bolts weighted and unweighted by bolt volume of various trees is 0–16% when the strip road spacing is 30 m the reason being the fact that the heaviest butt bolts are often more far away from the strip road than the top bolts.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
The paper deals with the relationships between macronutrients, ground vegetation and tree crop on a drained peatland area in Central Finland. The former herb-rich spruce swamp was drained in 1930s. The Norway spruce (Picea abies (L.) H. Karst.) stand was established by planting under a nurse crop of birch, which was removed later.
There was a negative correlation between the thickness of the peat layer and the volume and mean height of the growing stock. This was found to depend on the negative correlation prevailing between the potassium content of the topmost peat layer and the thickness of the peat cover. The deficiency of potassium is clearly discernible as deficiency symptoms in the needles, the intensity of which showed a strong correlation with the stand characteristics studied. Among the nutrient characteristics of the topmost peat layer, total potassium and the N/K and P/K ratios showed the closest correlation with the stand characteristics. The communities into which the ground vegetation was divided differed from each other with regard to the calcium content of the peat substrate.
The PDF includes a summary in English.
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Mannerkoski,
E-mail:
hm@mm.unknown
The paper describes the results obtained from an investigation into the effect of thinning of different intensity and fertilization on the depth and water equivalent of the snow cover as well as on the depth of the soil frost in a young Scots pine (Pinus sylvestris L.) stand growing on drained peatland in Central Finland. Thinnings and fertilization was carried out in 1968, and the snow cover was followed in the winters 1970/71 and 1971/72.
Only extremely heavy thinnings (60% of the volume) seemed to increase the depth and water equivalent of the snow cover. The indirect effect of fertilization on the snow cover was insignificant. In the clear-cut sample plot of the study, soil frost was either not found at all or the depths of the frozen soil layer was smaller than in the other plots. When deciding the silvicultural measures to be taken in the case of tree stands growing on drained peatlands, there seems to be reason to avoid radical thinnings. Otherwise, the favourable influence of the trees on a site on its water relationships will be diminished.
The PDF includes a summary in English.
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Päivänen,
E-mail:
jp@mm.unknown
The study deals with the trampling tolerance of forest vegetation in a Myrtillus type closed forest of Norway spruce (Picea abies (L.) H. Karst.), based on the effects of simulated trampling on the coverage and biomass on the field and between layers of the vegetation. The reliability of the results from the simulated trampling was tested by comparing them with those obtained from real trampling.
According to the results, the trampling tolerance of the bottom layers is greater than that of the field layer. The trampling tolerance of different species varies, so that grasses and dwarf shrubs have a higher tolerance capacity than herbs. Even light trampling of short duration caused noticeable changes in the coverage and biomass of the ground vegetation. Despite certain deficiencies, the simulated trampling gave parallel results of those obtained for real trampling.
The PDF includes a summary in English.
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Kellomäki,
E-mail:
sk@mm.unknown
The material consists of four Scots pine (Pinus sylvestris L.) stems from which 757 samples were taken from various heights and distances from the pith. According to the results, the number of rays and their sizes are greater at the stump level than higher up in the stem. The size increases, and the number decreases on moving from the pith outwards. However, there are differences between stems as regards the variation model. The ratio between the number of fusiform rays and that of uniseriate rays seems to be lower than anticipated earlier, about 1:40–1:50. The average proportion of ray volume varied from 5.6% to 7.3%.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
The paper lists the forest publications of forest scientific research published in Finland in 1975 in five scientific series: Acta Forestalia Fennica, Silva Fennica, Communicationes Instituti Forestalis Fenniae, Folia Forestales, and Metsäteho Reports.
The purpose of this study was to compare the development of Scots pine (Pinus sylvestris L.) seedlings sown on substrates off milled peat and milled bark. Mille peat, ordinary milled bark, milled inner bark waste, and a mixture of milled peat and milled bark in the ratio of 1:1, were all compared in the plastic greenhouse. In addition, two fertilization applications were used with milled park: ordinary surface fertilization and double surface fertilization. The germination and development were measured twice during the summer.
It is concluded that milled bark seems to be a rather useful substrate for use in plastic greenhouses, as long as its special requirements are taken into consideration. In the first measurement, there were no differences between the treatments, in the second measurements seedlings growing on a mixture of peat and bark were slightly more developed than the others. Growth of the seedlings was slightly better in ordinary milled bark. Double surface fertilization increased disease and mortality compared to ordinary fertilization.
The PDF includes a summary in English.
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Laatikainen,
E-mail:
pl@mm.unknown
The aim of the present study was to assess whether two-year old Betula verrucosa Ehrh. (now Betula pendula Roth.) transplants can be used in afforestation of drained peatlands and what factors affect the development of the young trees. The seedlings were planted in 1967. The site was repair planted next spring due to mortality caused by a undefined fungal disease, and the plantations were fertilized with NPK fertilizer (soil application. The seedlings were measured twice a year until the autumn 1970.
Only 28% of the original transplants, and 73.4% of the repair plantations were alive in 1970. In some cases, fertilization improved the results, while in others it was detrimental to the trees or had no effect on survival. According to peat analysis, the poor survival and development of the plants could be due to the too high ratios of N/Ca and N/P. Stunted or dead trees displayed often necrosis caused by Godronia multispora. According to the experiences, Betula verrucosa plantations are inferior to those obtained with Scots pine (Pinus sylvestris L.). In addition, the results indicate that in old draining areas calcium and phosphorus are often too low in comparison to nitrogen.
The PDF includes a summary in English.
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Lehtiniemi,
E-mail:
tl@mm.unknown
- Sarasto, E-mail: js@mm.unknown
This paper deals with the problem of optimal multiple use of forests. The concept of attractive visual environment is analysed following the framework of conditional reflexes and conditionalization of needs. Uniformity of landscape preferences among a group of persons, forest professionals working in district forestry boards in Southern Finland, who have similar education and working environment is studied in empirical part of this paper. The sample of 154 persons were sent a sociological questionnaire.
The preference distribution of forest officers and forest technicians were found very similar. Only poor condition for wood production as a landscape feature was considered clearly negative. The answers show the demand for rational and active working environment as a factor directing the landscape preferences.
The PDF includes a summary in English.
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Lovén,
E-mail:
ll@mm.unknown
The problem considered in this paper is how to analyse the usefulness of some average volume values of stems in predicting the average time consumption of some processors. In this connection, the usual arithmetic mean, the arithmetic mean weighted with volume and the geometric mean were used. The functions describing the dependence of time consumption per tree on the volume of the tree were obtained from previous studies, as were the stand properties.
The results were obtained with the aid of computer simulation techniques and the deterministic model described above. According to the results, the usual arithmetic mean is very applicable for predicting the time consumption. The geometric mean is nearly as good, or in some cases even better. However, as a rule its computation is much more tedious than that of the arithmetic average volume for the purpose.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
