Articles containing the keyword 'tuotos'

Curly birch (Betula pendula f. carelica Sok.) is characterized by large variations in stem form and the internal structure of the wood, and is generally divided in to four types on the basis of visible external stem characteristics. First plantation experiments in Finland in the 1920’s in experimental areas of the Finnish Forest Institute, had become ripe for cutting and were felled. The study material of this study consists of one 52-year old and three 42–43 -year old stands of curly birch.

The yield suitable for plywood manufacture from the oldest stand was 34,777 kg/ha and that of curly grained branch wood 39,452 kg/ha. The corresponding figures of the other stands were, on average 24,219 and 57,271 kg/ha. The yield from the stands were sold at the present-day price. The result was economically better than from any other forest tree species grown in Finland. The younger stands were obviously cut too early. It was concluded that the genetic quality of the seedlings used in the plantations in the 1920’s and 1930’s was not very high.

The PDF includes a summary in English.

• Raulo, E-mail: jr@mm.unknown
• Sirén, E-mail: gs@mm.unknown

The paper deals with the concepts of time consumption and output in forest work science. When output is defined as the inverse of time consumption and vice versa, it is possible to show the important consequences in probability functions. For instance, it is not the same if the dependent variable in a regression analysis is output or time consumption. Also, the average differ depending on if they are based on the time consumption figures or on the average output.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The aim of the study was to find out if it is possible to use Scots pine (Pinus sylvestris L.) seed from Central-Finnish origin in Northern Finland to supplement supply of local seeds. The principle has been to limit transfer of seeds to 200 km. According to this study, it seems possible to permit 300-400 km transfer of seeds at the same height above the sea level, not including the timber line area.

The author’s observations indicate that the trees originating from seeds of Central Finland at 20-35 years age withstand damage caused by snow and pine blister rust as well as the local provenience. However, the seedlings seem to be more susceptible to snow blight. Spraying of 2-3% sulphurated lime in the autumn before the arrival of snow proved to be most effective way to prevent the damage.

Southern proveniences have been found to grow faster than the local proveniences in Northern Finland. The stands of Tuomarniemi (Central Finland) and Rovaniemi (Northern Finland) provenances had no distinct difference in the summerwood percentage, and the volume weight of the Tuomarniemi provenience was higher than the weight of the provenience of Rovaniemi. The Tuomarniemi stand also gave largest yield, but the difference was probably due to partly at age difference of the sample trees. The naturally regenerated local provenance showed the greatest volume weight.

The article includes a summary in English.

• Sirén, E-mail: gs@mm.unknown

Examination of stands developed under natural conditions can be used to provide basis for comparison for study of the development and yield of stands treated with intermediate fellings. In Finland, the first investigation and the yield and the structure of natural normal stands were published in 1920. This investigation on development and yield of the natural forests of Kainuu in southeastern Northern Finland is based on 92 sample plots on three forest types; Empetrum-Vaccinium type (EVT), Empetrum-Calluna type (ECT) and Vaccinium-Myrtillus type (VMT).

The Scots pine (Pinus sylvestris L.) sample plots represented variation of age classes for construction of mean development series. The Norway spruce (Picea abies (L.) H. Karst.) of the region are so old that development series could be obtained only for dominant trees based on stem analysis.

The average development of Scots pine stand on EMT type within the region is on average more rapid and the yield in cubic volume quantitatively larger and structurally better than that on ECT type. Self-thinning during the early decades of EVT is slower. The pine stands are denser in the age of 70 in Kainuu compared to Central Northern Finland, but the development and yield are similar.

The development, yield and structure of natural Norway spruce stand on VMT proved considerably inferior to the average level of pine stands on EVT, and to a major part on ECT. The mixed pines on spruce sample plots have developed better than spruces of equal age. Spruce stands on VMT in the area developed markedly better than Geranium-Dryopteris-Myrtillus (GDMT) in Central Northern Finland.

It seems that a spruce stand seems to require more fertile site type in north than in the southern part of Finland. These fertile types are relative rare in the north. In the region, the best results are received with pine. As a rule, also the yield of birch (Betula sp.) is poor in the region.

The PDF includes a summary in English.

• Ilvessalo, E-mail: yi@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.

• Ilvessalo, E-mail: yi@mm.unknown

New growth and yield tables were prepared for Southern Finland. To finalize the tables, it had to be determined whether the forest site types developed by Cajanus could be used in mensurational research.

Comparative study was performed in 1916-1919 to study the growth of the trees in different forest site types. Total of 467 sample sites were measured in Southern and Central Finland. All the forest site types were found to have a distinctive vegetation typical to the site. It can be concluded that the ground vegetation can be used to determine the forest site type. The growth of trees was different in different forest site types, yet similar within each site type. The forest site types are uniform, natural and easy to determine, and can thus be used to classify the forest stands and used in mensurational research and a basis to growth and yield tables.

The PDF includes a summary in German.

• Ilvessalo, E-mail: yi@mm.unknown