Current issue: 58(5)
Silva Fennica vol. 19 no. 1 | 1985
Category : Article
Young Norway spruce (Picea abies (L.) H. Karst.) are susceptible to early summer frost damage. Birch (Betula pubescens Ehrh.) naturally colonize rich or fairly rich drained peatlands after clear cutting, and can provide protection for developing seedlings. The report describes the development of spruce stands after various types of handing of the birch nurse crops.
Different proportions of birch and spruces did not have any influence on the spruce stand production. In cases where the nurse crop stand is removed when the spruce stand age was 20 years and height 4 m the spruce suffered badly but recovered with time, reaching the spruce stand growing under a nurse stand within the next 20 years. The height growth of spruce depends on the density of the nurse stand, especially on fertile sites. The development of diameter growth also depends on the density of the nurse trees. Removal of the nurse stand in spruce stands on the sites concerned should be done when the spruce stand is 20 years old and at the height of 4 m.
The PDF includes a summary in English.
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Heikurainen,
E-mail:
lh@mm.unknown
Transects from upland to peatland sites were laid out so as to encounter a wide range of nutritional and hydrological conditions and volumetric soil samples were taken at 20 m intervals. For organic material, in particular peats, the correlation of ignition loss with CEC and total N were clearly higher when the variables were expressed volumetrically. The volumetric expression of variables made comparison of soils with varying organic matter contents possible. In preliminary analyses of the relationships between soil variables and dominant height of the tree stand on mineral soil sites volumetric exchangeable bases, pH and C/N -ratio in the raw humus layer showed a significant correlation.
The PDF includes a summary in Finnish.
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Westman,
E-mail:
cw@mm.unknown
- Laine, E-mail: jl@mm.unknown
- Starr, E-mail: ms@mm.unknown
Norway spruce (Picea abies (L.) H. Karst.) boards sawn from outer layers of logs were sampled from a sawmill in Northern Finland and another in Southern Finland. Test pieces 20 mm x 20 mm x 20 mm were selected according to maximum variation in growth ring width. Volumetric and longitudinal shrinkage from a soaked to a dry condition were measured. It was found that wood density correlated positively with the volumetric shrinkage but negatively with the longitudinal shrinkage. Dry density was a better predictor than basic density. With constant density and an increase in growth ring width, there was increased shrinkage, especially in samples from Northern Finland. Besides this, when density was kept constant, the shrinkage was higher in the spruce wood from Southern Finland than from Northern Finland.
The PDF includes a summary in Finnish.
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Kärkkäinen,
E-mail:
mk@mm.unknown
- Marcus, E-mail: mm@mm.unknown
Data management is pointed out as a phase of research process. It covers research activities from observation recording to data matrix derivation. Some concepts of logical and physical database implementation are introduced.
The TUTKA -software system is introduced and observed as an instrument of research data management. Attention is paid to TUTKA’s five design criteria. Database implementation and use with TUTKA are observed precisely. Three different phases of implementing a data base are specified. Finally, some aspects to the data management of forest research are presented.
The PDF includes a summary in English.
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Kaila,
E-mail:
ek@mm.unknown
The goal of this research was to study the position of forest supervisors, their education, number, pay system, professional organizations and work situations in Nordic countries. The study belonged to a joint Nordic project of the Nordic Research Council on Forest Operations. Participating in the actual work the number of forest supervisors were Denmark (year 1978) 715, Finland (1980) 8,000, Norway (1967) 1,055, and Sweden (1975) 6,400. In Denmark, 87% of the supervisors worked in forestry, in Finland 91%, in Norway 98% and in Sweden 86%.
Forest supervisor education started at the end of the last century. In the 1950s and 1960s the forest supervisors’ education has been renewed in all four countries. Supervisors have a special 1 to 4.5 years’ training, but many have a forest technician’s education, too. In Finland and Sweden forest supervisor education was reformed at the end of the 1970s. Supervisors work in functional as well as in regional organizations. In Nordic countries, supervisors are paid monthly salaries. Salaries are a little higher in private than in public sector companies. In 1981 the start salary in Finland was 3,107 FIM and in Sweden in 1980 about 4,425 FIM. Most supervisors in the Nordic countries belong to some union.
The PDF includes a summary in English.
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Juntunen,
E-mail:
mj@mm.unknown
- Engsås, E-mail: je@mm.unknown
- Gustafsson, E-mail: lg@mm.unknown
- Mäkinen, E-mail: pm@mm.unknown
- Theilby, E-mail: ft@mm.unknown
- Vik, E-mail: tv@mm.unknown
Variation in tracheid morphology were examined for the bole wood of lodgepole pine (Pinus contorta Douglas ex Loudon) grown in Southern and Central Finland. Tracheid lengths were examined in a fast-grown and in slow-grown trees from three stands. Tracheid length increased with increasing height to 4–8 metres and decreased after that, and increased also with increasing age from the pith. The variation between stems was high. The shortest tracheids were about 1.11 mm near the piths and the longest about 4.10 mm near the bark.
Tracheid diameter and cell wall thickness were measured for the total number of 16 stems from Southern and Central Finland. Tracheid diameter increased with increasing distance from pith and the largest tracheids were at a height of 4–8 metres. Cell wall thickness varied independently of height in the stem. Summerwood cell wall thickness was twice that of springwood. There was a difference of 0.6 μm in springwood and 1.0 μm in summerwood double cell wall thickness between the two stands. Cell wall percentage was 29±4.7 in springwood and 69±7.3 in summerwood.
The PDF includes a summary in English.
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Saranpää,
E-mail:
ps@mm.unknown
Surface temperature during two prescribed burnings were measured in 1983 in Evo, Southern Finland. Surface temperatures in relation to the amount of slash burned, energy released during the fires, and the fire intensities were studied. The fire intensity was also measured during a third burn. The Lake Nimetön site was burned int the end of May. Due to the uneven distribution of slash, colonization by Calamagrostis arundinacea and the spring moisture, the burning was very uneven. Surface temperatures varied between 410–809°C and the intensity of fire was low (range 0–900 kW/m).
The fire intensity on the other sites burned in May was also low (880 kW/m). During the burn in August the surface temperatures varied between 701–869°C and the intensity of fire was moderate (1,170 kW/m). Slash was burned more evenly and more thoroughly due to the dryness of the site and slash and the fact that grasses and other herbs were not abundant.
The PDF includes a summary in Finnish.
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Vasander,
E-mail:
hv@mm.unknown
- Lindholm, E-mail: tl@mm.unknown
Ascocalyx abietina (now Gremmeniella abietina Lagerb.) infects Scots pine (Pinus sylvestris L.) by means of ascospores or conidia. Ascospores are dispersed by the wind, while the conidia are splash dispersed. The infection rate is positively correlated with the number of inocula. The aim of this study was to determine the extent to which G. abietina spreads to the trees surrounding the diseased trees and to find the correct time to perform sanitation cutting.
The results were obtained from Ascocalyx-inventory carried out in a Scots pine progeny test at Loppi, Southern Finland. Three Siberian provenances were totally destroyed, while the Finnish progenies remained relatively healthy. The two rows adjacent to the destroyed plots were inventoried separately.
There were 29.7% more diseased or dead trees in the two adjacent rows than in the rest of the same plots. The difference was statistically significant. The trees had probably been infected by conidia, because the effect of the destroyed plot only extended to the adjacent two rows. Furthermore, pycnidia had mainly developed on the dead shoots.
On the basis of the life cycle of the fungus and the results, the correct time to carry out sanitation cutting is the first winter after the disease symptoms have appeared. If it is done later, the disease could be spread and bark beetles (Tomicus spp.) could propagate in dying trees. Susceptible provenances may spread the disease to surrounding resistant trees owing to the increasing number of spores.
The PDF includes a summary in English.
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Uotila,
E-mail:
au@mm.unknown
