Current issue: 58(5)
Silva Fennica vol. 11 | 1977
Category : Article
Pair numbers of breeding land birds were estimated from line transects data collected in Finland in 1936–76. The changes observed in the bird populations are in this paper compared with data obtained in the Finnish forest inventories, particularly made in 1951–53 and 1971–76. It is concluded that modern forestry has considerable impact on the breeding bird fauna. In general, more species have increased than decreased due to changes in the forests. Areas affected by forestry are more favourable habitats for many species than natural forests, but, on the other hand, there are certain species which are greatly harmed by the effects of modern forestry.
The PDF includes a summary in English.
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Järvinen,
E-mail:
oj@mm.unknown
- Kuusela, E-mail: kk@mm.unknown
- Väisänen, E-mail: rv@mm.unknown
The structural matter production of selected plant species of a ground cover community was determined in relation to light available for photosynthesis. The resulting functions were applied in a situation where the light reaching the ground cover was controlled by the dynamics of the tree crown strata, and the occurrence of different plant species at different stages of succession was determined on the basis of their production of structural matter in actual light conditions. The possible strategies involved in adaptation to a successional environment have been discussed.
The PDF includes a summary in Finnish.
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Kellomäki,
E-mail:
sk@mm.unknown
- Hari, E-mail: ph@mm.unknown
- Kauppi, E-mail: pk@mm.unknown
- Väisänen, E-mail: ev@mm.unknown
A quantitative method for determining the annual growth level of plant species has been presented. In particular, attention was paid to the dependence of the growth level on the amount of light available for photosynthesis. A mathematical model for the dependence of structural matter production on photosynthetic production has been presented for some plant species.
The study is based on the assumption that the total amount of annual net photosynthesis plays a role of primary importance in determining the relationship between photosynthetic production and structural matter production. The basic environmental factors determining the photosynthetic rate are light and temperature, if the water and nutrient supply is adequate. The dependence of photosynthetic rate on light and temperature was determined by monitoring the CO2 uptake rate of natural plant populations between the photosynthetic levels of different plant populations with an infrared gas analyser.
The PDF includes a summary in Finnish.
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Väisänen,
E-mail:
ev@mm.unknown
- Hari, E-mail: ph@mm.unknown
- Kellomäki, E-mail: sk@mm.unknown
The aim of the paper was to investigate the potentials offered by trails in guiding recreational activity. The study is based on interviews and questionnaires concerning recreationists using two recreation areas owned by the city of Helsinki in Southern Finland. According to the results, the recreationists visit terrain without trails every time they visit a recreation area. The main reason for this was obtaining varying recreational experiences. The recreationists used, however, the same route nearly every visit, which suggests that trails have a great potential in guiding reacreational activities. Special attention was paid to the role of trails in activities involving physical exercise. The correlation between the socio-economic background of recreationists and their preferences for trails was very low.
The PDF includes a summary in English.
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Kellomäki,
E-mail:
sk@mm.unknown
The physical strain put on forest workers and work time consumption during pulpwood cutting were compared when the bolts were stacked at the side of strip road, the strip road spacings being 15–25 m and 26–35 m, and when stacked at scattered points along the cutting strip.
When stacking at scattered points along cutting strip work time consumption was 17–21% and the heart rate 9–12% less than when stacking at the side of the strip road, strip road spacing being 15–25 m. When the strip road spacing was increased to 26–35 m, the time consumption increased by 18–30%, but the heart rate appeared unchanged. This result suggests that the forest worker compensates for increased physical strain caused by an increased stacking distance by changing his working technique and rate and by increasing the number of his breaks.
The PDF includes a summary in English.
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Valonen,
E-mail:
pv@mm.unknown
The Nordic working group for forest fertilization is a group of research workers from the Nordic countries Denmark, Finland, Norway and Sweden, which has been working on plant nutrition questions and forest amelioration problems. The group has met annually to discuss current problems, hitherto mostly concerning forest fertilization. In 1976 the question of future working forms came up, and the group decided to arrange a symposium on the subject Nutrient cycle in tree stands in 1977.
This symposium took place in Harjavalta and Ikalis in Finland from the 29th of August to 1st of September 1977. During the symposium 12 papers were presented, which are published in the following, either in full or as summaries of a given lecture. Part of the lectures are in English and part in Swedish.
The paper includes the following titles:
A bioelement budget of an old Scots pine forest in Central Sweden
Mobilization of plant nutrients in a Scots pine forest Mor in Central Sweden
Accumulation of organic matter and nitrogen on sand dunes following sand fixation and planting of dwarf mountain pine
Sambandet mellan torvmarkstyp och yttorvens näringshalt
Changes in the amounts of inorganic nutrients in the soil after clear-felling
Plant nutrient balance in decoration greenery cultivation
The effect of forest fertilization on primary production and nutrient cycling in the forest ecosystem
Förändringar i humuslagret efter skogsgödling
Balanserad näringsupptagning och behovet av gödsling i trädbestånd på näringsfattiga torvmarker
Of fertilization on nutrient contents in needles and litter fall of Scots pine on dwarf shrub pine swamp
Micro-nutrient deficiencies cause growth disturbances in trees
Tallarnas växtstörningar, markens näringsbalans och micronäringsbrist
The paper describes the use of printed area in some scientific series concerned with forestry. The material consisted of 8 scientific series, the total number of analysed pages being 2,942. According to the results, the use of printed area was more efficient in journals and other similar periodicals which included several scientific papers than in series published as separate issues. The main reason was the more efficient editorial make-up. The Finnish papers included less figures but more tables than foreign series. There were marked differences between series irrespective of the country of origin. The average figure area varied from 60 to 180 cm2 between series, for example. According to the observations there are good possibilities for making more efficient use of the printed area available.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
The study is part of a project designed to elucidate the nutrient budget of a Scots pine (Pinus sylvestris L.) stand. Results of variation in the nutrient contents were compared with those obtained for the previous growing season.
The potassium and calcium contents varied the greatest in the humus layer. However, in the bottom and field layer vegetation and needles the variation in the nitrogen content was the greatest. The nutrient contents of the needles were affected by the physiological stage of development, needle age and the position in the crown of the tree. The nutrient content of the rainfall increased in the order: free rainfall, throughfall, and stem flow.
The PDF includes a summary in Finnish.
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Lehtonen,
E-mail:
il@mm.unknown
The amounts of harvestable logging residues and stump and root wood were examined in the area where 100,000 solid m3 of stemwood was cut in 1975. The cutting amounts of stemwood from work sites suitable for harvesting of logging residues was 35,000 m3, and suitable for harvesting of stump and root wood 38,000 m3. The increase in the yield of wood (without bark) from logging residues compared with the unbarked stemwood was 2.4%. The same percentage of wood from stump and root wood was 5.0–5.8% depending on the harvesting loss.
The PDF includes a summary in Finnish.
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Mäkelä,
E-mail:
mm@mm.unknown
The object of the study was to give a tentative indication of the realized economic significance of the principal forest (forestry land) uses in Finnish Lapland. Data concerns the years of the 1970s. Nowadays timber harvesting generates a major part of the total value of production. Recreation (tourism) is in second place. Reindeer husbandry, collection of berries and mushrooms and hunting together produce, in the best years, an output value which is about one fifth of that of timber harvesting. Non-timber uses together produce a rather significant portion on the total value of the integrated forestry output.
The PDF includes a summary in Finnish.
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Saastamoinen,
E-mail:
os@mm.unknown
The aim of the present study was to investigate the trampling tolerance of forest ground cover of the Calluna, Vaccinium and Myrtillus type sites. Positive correlation was found between the site fertility and trampling tolerance of plant communities. Annual trampling at level of about 16,000 visits per hectare decreased the biomass of the ground cover to almost half of the original amount, and annual trampling of about 160,000 visits per hectare completely destroyed the forest ground cover irrespective of site fertility. Comparisons made between herb and grass dominated forest ground cover showed that herb and grass cover is in the long run the best alternative for the management of ground cover in intensively used recreation areas.
The PDF includes a summary in Finnish.
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Kellomäki,
E-mail:
sk@mm.unknown
A method is presented in this study for calculating the basic density of whole tree- and logging residue chips and the results of trial measurements on some commonly used chip sorts. The basic density of Scots pine whole tree chips was found to be 1–18 kg/m3 smaller than that of pine pulpwood of the same age. The basic density of Norway spruce whole tree chips was 4–22 kg/m3 greater than that of similar aged pulpwood. The basic density of birch whole tree chips was 4–16 kg/m3 and grey alder whole tree chips 7–24 kg/m3 greater than pulpwood of the same age. The basic density of conifer logging residue chips was considerably greater than that of pine and spruce whole tree ships.
The PDF includes a summary in English.
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Mäkelä,
E-mail:
mm@mm.unknown
The maps concerning the natural distribution of oak (Quercus robur L.) have proved most unreliable in detailed examination. In this paper, the author has collected his observations on natural oak in the westernmost parts of the province of Uusimaa and the easternmost parts of province of Turunmaa, the islands included. Furthermore, the paper includes some viewpoints which must be considered as criteria when determining the naturality of the stand in question. Future borders of oak’s distribution range must be moved farther up north to replace the earlier views of the northern limit of natural oak in Finland.
The PDF includes a summary in English.
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Rainio,
E-mail:
rr@mm.unknown
The Finnish Society of Forest Science arranged on 16 March 1977 a seminar where targets of forestry research and communication were discussed by scientists, as well as publicists and users of scientific information. This paper includes summaries of some of the speeches and the reports of the workshops. The theme of the seminar was Forest science and practice – Do we understand each other?
The paper introduces the science policy agenda of the Finnish Society of Forest Science that defines the role of the society and the principals that are required from research work.
The first part of this paper consists of a study based on the available literature concerning the analysis of chip quality in the sulphate pulp process and the factors having an effect on chip quality. Using the empirical material, the suitability of the Williams chip classifier in evaluating the quality of chips made by the Algol chipper is first studied. The distribution of length and thickness of pulpwood-, long logs-, whole tree-, and logging residue chips in different conditions determined by screening is then presented.
The PDF includes a summary in English.
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Mäkelä,
E-mail:
mm@mm.unknown
According to the literature, the mechanical strength of the green reaction wood of softwood species (compression wood) is greater than that of normal wood. Drying increases the mechanical strength but less in reaction wood than in normal wood. In particular, the tensile strength along the grain and the impact strength are lower than in normal wood. The compression strength and possibly bending strength are greater, however.
The properties of the reaction wood of hardwood species (tension wood) differ from those of softwoods. When green, all mechanical properties are weaker than those of normal wood. When dried, the tensile strength and impact strength are better and compression strength lower. There is no great difference in the bending strength.
When the higher density of reaction wood is not taken into account and there are no impact forces, the mechanical strength of reaction wood in sawn goods etc. does not differ so much from that of normal wood. The harmful effect of knots, for example, can in practice be much greater.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
- Raivonen, E-mail: mr@mm.unknown
The aim of the present paper was to study the annual production of Pleurozium schreberi (Brid.) Mitt., Hylocomnium splendens (Hedw.) B.S.G and Dicranum polysetum Sw. as a function of light available for photosynthesis. The productivity of the above moss species is studied using the harvested quadrats method in Norway spruce (Picea abies) stands of the Myrtillus site type representing different stand density classes (basal area from 0 to 34 m2/ha) in Southern Finland.
The annual production of each species in different stands was correlated with the amount of light available for photosynthesis i.e. with the photosynthetic production. Functions for the dependence of productivity on light conditions were produced for each species. The individual functions and their ecological significance is discussed. The adaptation of each species to low light intensity is evident since no meaningful addition to production takes place when the photosynthetic light ratio reaches values greater than 0.3–0.4. In other words, the level of photosynthesis which is 30–40% of that possible in the open, provides sufficient supply of carbohydrates or the basic functions of the moss species studied. Pleurozium schreberi and Dicranum polysetum seem to have greater light requirements than Hylocomnium splendens.
The PDF includes a summary in Finnish.
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Kellomäki,
E-mail:
sk@mm.unknown
- Hari, E-mail: ph@mm.unknown
- Väisänen, E-mail: ev@mm.unknown
This study, comprising three experiments, aims to determine the effect of the geographical origin of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seeds, and the duration of the time lag between the moisture treatment and subsequent irradiation on the gamma-irradiation sensitivity of seeds.
The studies showed that the greater the irradiation dose seeds were subjected to the slower the rate of germination. In general, small radiation doses (250–1,000 rad) had a stimulating effect and the final germination percentage (36–40 days) increased. However, when the level was further increased, the germination percentage decreased. Air-dry and moistened seeds withstood irradiation better than others. In a study with moistened seeds from different geographical sources, pine and spruce seeds from Northern Finland were less able to withstand irradiation than those originating from the south.
The PDF includes a summary in English.
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Lehtiniemi,
E-mail:
tl@mm.unknown
The aim of this study was to determine under what conditions and with what premises the growing of Betula pubescens Ehrh. is an economically competitive alternative to the growing of Scots pine (Pinus sylvestris L.) in drained peatlands. The basic material consisted of all drainage projects in Ostrobothnia in Western Finland in 1937–38 and 1957–59, according to the archives of the Central Board of Forestry Tapio, including such areas that were at least moderately fertile and had birch dominated young stands or no tree cover. A total of 202 sample plots were measured.
According to the results, the discounted timber yield of the thinned B. pubescens stands is about 10% greater than that of untreated stands. The removing of birch seedlings and the subsequent growing of fully stocked Scots pine is more profitable than growing B. pubescens stands only if the establishment and subsequent development of the pine stand involve no costs. If the site in question is a fertile open drained peatland, establishment of a pine stand is obviously a better financial proposition than a naturally regenerated birch stand. However, if there is already a fully stocked young birch stand on the site, it is more economical to let it grow using a shortish rotation time.
The PDF includes a summary in English.
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Keltikangas,
E-mail:
mk@mm.unknown
- Seppälä, E-mail: ks@mm.unknown
In the densely populated Central Europe, forestry has always had different functions than in Scandinavia or Canada. Today the increasing pressures on the environment and more numerous demands of the people have put emphasis on environmental management and the demands of recreation in forest management practiced in the area. This paper outlines the trends in the utilization of forests in Central Europe, and especially in the Federal Republic of Germany, due to these changing targets. The regulations concerning forestry in Baden-Würtenber, and the forest plan of the Bavarian state forests are used as an example to clarify the principals of forest management and planning.
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Schmidt-Vogt,
E-mail:
hs@mm.unknown
In most pine swamp stands on drained peatlands the dwarf-shrubs are rather important biomass producers. The aim of the experiment was to determine the effect of killing off the dwarf-shrub vegetation on the subsequent development of Scots pine (Pinus sylvestris L.) stand. The dwarf-shrub vegetation was killed by means of herbicides. The results show that by removing competition by the dwarf-shrub vegetation on drained pine swamps, it is possible to pass onto the trees at least some of the freed growth potential.
The PDF includes a summary in Finnish.
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Sarasto,
E-mail:
js@mm.unknown
- Seppälä, E-mail: ks@mm.unknown
In the boreal zone, the environmental control of growth rate, i.e. the rate of irreversible change in shoot dimensions, is assumed to be dominated by temperature. Promnitz (1975) emphasises that in boreal and temperate zones storage of photosynthetic products is an essential part of the growth process, and thus direct interaction between growth rate and radiation is not evident. The aim of the present study was to investigate the control of daily structural matter production in populations of Avenella flexuosa (L.) Drejer. Special attention was paid to the role of temperature and radiation in addition to the self-regulation of the plants themselves.
Temperature and self-regulation were found to explain over 90% of the daily variation of growth rate. Introduction of radiation into the analysis did not increase the explanatory power of the growth model based on temperature and self-regulation.
The PDF includes a summary in Finnish.
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Lehtonen,
E-mail:
il@mm.unknown
- Hari, E-mail: ph@mm.unknown
- Kellomäki, E-mail: sk@mm.unknown
- Väisänen, E-mail: ev@mm.unknown
According to the available literature, the appearance of Parana pine (Araucaria angustifolia (Bertol.) Kuntze) wood resembles that of Scots pine (Pinus sylvestris L.). The anatomy is quite different, however. There are no resin canals and fusiform rays with resin canals in Parana pine. They are abundant in Scots pine, however. The basic density of Parana pine is higher. In both species the density increases from the pith outwards, the maximum being reached at the age of 100 years. Compression wood is more common in Parana pine than in Scots pine, and this makes the longitudinal shrinkage of Parana pine greater than that of Scots pine. Otherwise the shrinkage properties do not differ. The mechanical strength is of the same magnitude with the exception of hardness, where Parana pine is superior.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
In 1975 the roundwood transport in Finland, which was mostly floated in the inland waters, accounted for 45% of the total transport performance and for 25% of the total transport volume. The paper describes the Finnish inland waterway fleet in 1975. The information was collected from the material of navigation inspectors who yearly inspect the seaworthiness of the merchant ships. The number of inspected vessels was 778. Of those 495 were tugs, 118 passenger boats, 71 warping boats, and the others totalled 94. The average power of tugs was 65 kW and that of warping boats 16 kW.
The PDF includes a summary in Finnish and French.
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Roitto,
E-mail:
yr@mm.unknown
