Current issue: 58(5)
Articles containing the keyword 'Southern Finland'
Category : Article
It was examined whether the present site classification method, and especially its applicability to site productivity estimation, could be improved in upland Scots pine (Pinus sylvestris L.) forests in Southern Finland by developing a classification key based on Two-way Indicator Species Analysis (TWINSPAN), and/or by inclusion of soil texture, stoniness and the humus layer depth more closely in the classification method. TWINSPAN clusters (TW) explained 71%, and forest site types (FST) 64% of the variation in site index (SI) (H100). When soil texture (TEXT) was added to the regression model, the explanatory power increased to 82% (SI = TW + TW * TEXT) and to 80% (SI = FST + FST * TEXT), respectively. Soil texture alone explained 69% of the variation in site index. The influence of stoniness on site index was significant (P <0.05) on sorted medium sand soils and on medium and fine sand moraine soils. The thickness of the humus layer (2–6 cm) was not significantly (P=0.1) related to site index.
It is suggested that the proposed TWINSPAN classification cannot replace the present forest site type system in Scots pine stands in Southern Finland. However, the TWINSPAN key may be used to aid the identification of forest types. The observation of dominant soil texture within each forest type is recommended.
The PDF includes an abstract in Finnish.
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Nieppola,
E-mail:
jn@mm.unknown
Basic density and absorbed energy in impact bending were measured for 500 Norway spruce (Picea abies (L.) H. Karst.) samples from Northern and Southern Finland. Statistical analysis showed that the relationship between impact strength and basic density was significant and regression analysis showed that it was linear.
Furthermore, with constant density, the impact strength was higher in Northern than in Southern Finland. This was due to growth ring width: i.e. when density was kept constant the impact strength increased with decreasing growth ring width. In addition, when the growth ring width was kept constant, the basic density of wood was higher in Southern Finland than in Northern Finland.
The PDF includes a summary in English.
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Saranpää,
E-mail:
ps@mm.unknown
A population consisting of 450 Norway spruce (Picea abies (L.) H. Karst.) samples was gathered from northern and southern Finnish wood. The static bending strength was affected greatly by the density of the wood. However, keeping the density constant, the bending strength was higher in northern than in southern Finnish wood. The reason was the effect of the growth ring width.
The basic density was affected by the growth rate. Keeping the growth ring width constant, the basic density was over 5 kg/m3 lower in northern than in southern Finnish wood. This result supports the earlier findings on the effect of latitude.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
- Dumell, E-mail: od@mm.unknown
Snow and rime, attached to branches of conifers, seriously damaged forests in a region of 11,000 km2 in Southern Finland during a passage of two nearly occluded cyclones in 1959. The roles of different weather elements were studied by considering the variations occurring in them over this region and its surroundings. Damage occurred only inside an accentuated pattern of copious orographic precipitation. Precipitation only became attached to and retained on branches in such parts of the area where temperature varied on both sides of freezing point but did not exceed 0.6°C. Furthermore, damage only occurred in forests where rime formed (above a certain level and on sloping towards the prevailing wind).
The PDF includes a summary in English.
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Solantie,
E-mail:
rs@mm.unknown
- Ahti, E-mail: ka@mm.unknown
Male and female flowering, cone crop, and some vegetative characteristics were studied in grafts 10 to 16 years of age in a clonal seed orchard of Scots pine (Pinus sylvestris L.). Genetic variation was found between clones in flowering as well as in cone production. Clone evaluation resulted in similar classifications of clones in different years. A regression analysis showed that crown size clearly increased but previous height growth slightly decreased flowering and cone production. The percentage of pollinated female strobili did not differ between clones.
The PDF includes a summary in English.
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Tormilainen,
E-mail:
mt@mm.unknown
The present study is an attempt to clarify the decrease in growth, or the increment loss, caused by sudden reduction of growth of the growing stock below a certain level, and to find a method for its determination. Increment loss is defined as a decrease in growth during the rotation due to a deficient stock volume. The material consists of Koivisto’s yield tables for repeatedly thinned stands in Southern Finland, and the results of the Third National Forest Inventory concerning the mean volume and increment in the productive sites.
For the calculation of increment loss three formulae were constructed where the increment loss is calculated 1) as the difference between the removal by thinnings in normally developed stands during a time equal with the period of deficient stock and the suddenly removed stock, 2) according to the compound interest calculation principle as the sum of the differences which are obtained by subtracting from the removal in each thinning during the period of deficient stock its initial value, and 3) as the straight interest of the stock deficiency during the period of deficient stock.
According to the calculations, the increment loss is greatest in stands to be grown, viz. 50 m3 solid measure excluding bark per hectare tended Norway spruce stands on Oxalis-Myrtillus type sites at 40% deficiency below minimum stock. In stands to be regenerated the losses are, too, greatest in the similar stands. It exceeds 200 m3/ha when stands younger than 50 years have to been regenerated and the removal amounts to 50% of the stock. In stands to be regenerated the increment loss for spruce, due to the slow initial development by the species, is greater than for Scots pine and birch. The loss is the same at different period of age if the relative deficiency of the stock is of equal size.
According to the study, each stand has a characteristic variation in the increment loss which depends mainly on the relative degree of deficiency from the minimum stock. The formulae and methods can be used to determine the increment loss in average and better stands in Southern Finland when the stock suddenly decreases.
The PDF includes a summary in English.
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Matilainen,
E-mail:
tm@mm.unknown
Metsähallitus (Forest Service) commissioned a study about condition of forests on the coast of Gulf of Finland in the Karelian Isthmus. The study was made because of a growing concern on overcutting of the private forests in the area. Dominant tree species in the area is Scots pine (Pinus sylvestris L.). In fresh mineral soil sites Norway spruce (Picea abies (L.) H. Karst.) grows in mixed forest with pine or as pure stands. The forests are in average 50 to 70 years old. Younger or older stands are less frequent.
At the beginning of 18th century the local peasants sold plots for Russians, and a villa area was created along the coast. When Finland became independent, many of the properties changed owners. Timber harvesting of the forests increased and many small sawmills increased the demand of wood. Because of the cuttings, productivity of the forests decreases and danger for wind damage in the forests increases.
The author suggests that legislation created to prevent deforestation as well as counselling should be applied to improve forest management. In addition, a protective area should be formed in the Karelian Isthmus where forest preserving directives should be followed.
A summary in German is included in the PDF.
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Ilvessalo,
E-mail:
li@mm.unknown
Category : Article
The study is based chiefly on statistics of forest fires in the state forests in 1911-1921, published in the annual reports of Board of Forests (now Metsähallitus, Forest Service). Forest fires burned 37,200 hectares of forests in the state forests in 1911-1921. In Southern Finland the number of fires was 795 and in the Northern Finland 610. The frequency of forest fires is higher in south because of the denser population in the area. The average forest fire ranged 118 hectares in Southern Finland and 39 hectares in the north. Fires broke out most often because of careless use of fire. Weather conditions and the type of the forests influenced the risk of fire. In the north, risk for forest fire is lower because of the high proportion of peatlands. Only 14% of the fires burn the trees of the stand. In Southern Finland 50% of the fires and in Northern Finland 42% of the fires damage only part of the stand. Rest of the fires were surface fires that do not burn the trees. The value of damages by forest fires in the state forests in 1901-1922 was annually in average 139,400 Finnish marks.
The PDF includes a summary in English.
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Saari,
E-mail:
es@mm.unknown
The first proper growth and yield tables were prepared in Finland already in 1872, but they have been used little as the needs of forestry and forest sciences increased. One of the problems of the old yield tables was how the site quality classes are determined. The new growth and yield tables use the forest site type classification, which enables the use of same site types for all tree species. This makes it possible to compare the growth of different tree species in same kind of sites. The tables also use stem frequency distribution series. In the first stage, the tables were prepared for Southern and Central Finland.
The PDF includes a summary in German.
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Ilvessalo,
E-mail:
yi@mm.unknown
