Articles by Erkki K. Kalela

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes problems specific to forest management of remote forests areas. The growth of the forests in these areas are often low due to, for instance, northern location.

• Kalela, E-mail: ek@mm.unknown

Silva Fennica Issue 64 includes presentations held in 1947 in the third professional development courses, arranged for foresters working in the public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation describes how the natural processes of forests and succession could be utilized in forest management and silviculture.

• Kalela, E-mail: ek@mm.unknown

The size of the field and the ditching on it as well as the condition of the field at the time of the surrender of Porkkala area (from Finland to Russia) play an important role on how far the natural regeneration of the fields has progressed.

Larger open fields have naturally regenerated only on sides where the surrounding forest can spread the seeds or the thicket of saplings has reached, whereas small parcels of fields have normally been fully forested. Most important species have been e.g. silver birch and pubescent birch, grey and common alders and European aspen as well as pine and spruce. The broad leaved species are dominant.     

The PDF contains a summary in Finnish.

• Kalela, E-mail: ek@mm.unknown

The article presents the results of the studies about the horizontal root systems of pine. The results have been obtained with the method developed by the author.

The size of the root system varies very strongly during the growing period. The amount of roots is at the smallest in the spring, increasing then rapidly and peaking at the end of July. After that the amount of roots decreases again against the winter to the same size than in the spring. The differences are due the changes in the amount of the smallest roots. There seem to be no big differences in the amount of roots between stand of different ages.

After the thinning there is a drop in the amount of roots on the stand level, but after two growing periods then standing trees have taken over the unused land. However after selection felling the less vital trees are not capable of utilizing the vacant resource as effectively.     

The PDF contains a summary in Finnish. 

• Kalela, E-mail: ek@mm.unknown

Root systems of a Scots pine (Pinus sylvestris L.) stands of seed trees on a Vaccinium sites in Southern Finland were studied by taking soil samples around the seed trees. The results show that root system of an old Scots pine spreads relatively evenly around the tree up to at least 10 meters from the stem. The densest part of the root system is near the stem, which part is often acentric. This is probably due to root competition in the early stages of growth of the tree.

Root systems of the seed trees affect stocking of the site with seedlings and the growth of the seedlings. The root competition can cause, for instance, uneven grouping of the seedlings. It seems that the largest trees of a stand have the most even root system. It is therefore recommended to choose the strongest trees of the stand as seed trees, to ensure even distribution of seedlings.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown

The purpose of the investigation was to study the amount, quality and distribution by layers of depth of horizontal roots in Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) stands in Southern Finland. The sample plots included stands on soil varying from sandy to stony, and stands of  varying ages from seedling stands to an old stand, in Myrtillus and Vaccinium type forests.

In a Norway spruce stand, the amount of roots increases rapidly and reaches its maximum, about 450 meters/m³, at an age of 100-110 years. In a Scots pine stand the maximum, about 370 m/m³, is reached earlier, at an age of 60-70 years. The root system of pine expands more rapidly than that of spruce. The total length of the horizontal root system of pine amounts to 1,000 m soon after 40 years of growth, of spruce at the age of 60. Later the situation changes, and at the age of 110 the root systems of both species are about the same size, but older trees of spruce have more extensive root system.

Majority of horizontal roots are under 1 mm in diameter. Of the horizontal roots of spruce stands the majority lie in the humus layer and in the topmost mineral soil stratum. Over half of horizontal spruce roots are, thus, at a maximum depth of 5 cm, while majority of the roots of Scots pine lie at maximum in depth of 10 cm. At the same layer grow also the roots of the ground vegetation, which may affect the competition between the species.

The PDF includes a summary in English.

• Kalela, E-mail: ek@mm.unknown

The tendency of successional development from young vegetation, rich in species and exposed to chance factors, towards regular plant communities, is found all around the world. Thee ecological groups of trees seem to be present in all forest regions in the world, namely the pioneer and the climax species, and a group of pre-climax species that can be ecologically either near the pioneer or the climax species. The succession of tree species in forest always leads to a climax stand, determined by climate, quality of soil and the mutual biotical strengths of the tree species in the region.

This division into ecological groups greatly facilitates choosing among different methods of treating stands and understanding the silvicultural methods of foreign regions. Stands formed by species of the same group must follow the same lines in their silvicultural treatment. For instance, mixed stand consisting of both pioneer and climax species represents a transition stage, in which the climax species strive for dominating position, and preservation of pioneer species is difficult. This indicates the broad lines for management of the stand. Also, regeneration methods of pioneer and climax species must be different. Studying the succession of natural forests can be used as a means to reach the highest possible silvicultural level. This is one reason why the preservation and study of virgin forests still in existence is indispensable.

The PDF includes a summary in Finnish.

• Kalela, E-mail: ek@mm.unknown

Systematic resin collection has not been practiced in Finland or other Nordic areas. One reason is the short growing season. Also, the local pine species, Scots pine (Pinus sylvestris L.) gives smaller resin yield than the southern species, such as Pinus maritima. In Nordic boreal forests resin has been collected only in the Soviet Union, where it has been practised also in Eastern Karelia, near the Finnish border. Resin collection experiments were arranged in former resin collection stands in Karelia in 1943. A so-called German method for running resin had been used in the stands. 30-40 sample trees were chosen in five sample sites.

Forest type did not have big influence in the resin yield. The yield seemed to be slightly higher in Scots pine stands growing in fertile sites compared to poorer sites. The diameter of the tree had largest effect on the yield. It is recommended to focus on stands with large trees, and trees with a large, vital crown. In this kind of stands it is possible to get best yield in relation to the work required. The height of the patch that was cut in the stem had no influence on the yield. The size of the patch should, however, not exceed 35-50% of the diameter of the tree.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown

The study is based on observations in a Scots pine (Pinus sylvestris L.) stand on a dry upland forest site in Karhumäki, where a 10-15-year old seedling stand grew under a hold-overs of larger trees that had been left in the site in a previous felling. The root systems of 80-120 cm tall seedlings growing around single mother trees were unearthed. Root maps were drawn of the root systems of 120 seedlings.

No seedlings grew around old, large hold-overs. It seems that seedlings could not compete with their root system. If the hold-overs were stunted in their growth, seedlings grew also under the canopy of the mother tree. 90% of the seedlings had a tap root. Rest of the roots grew horisontally in the topsoil. Around a vigorous mother tree, the seedlings grew their roots away from the mother tree. Hold-overs that had belonged originally to the lower canopy layer of the old forest did not have similar effect on the root orientation of the seedlings. Their roots had been previously affected by trees of higher canopy layer, later removed in the felling.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown

Total of 1,305 forest fires was ignited in 1925-1934 in the forests insured by the Metsänomistajain Keskinäinen Metsäpaloapuyhdistys (The Forest Owners' Mutual Forest Fire Insurance Company and the Keskinäinen Vakuutusyhtiö Sampo (The Sampo Mutual Insurance Company). The variation was large: from 34 fires in 1928 to 362 fires in 1933. The forest fires were most abundant in the county of Oulu and Häme. The average size of the burned areas varied from 2.4 hectares to 30.5 hectares. The area of forests that had forest fire insurance increased steadily from 2.2 million hectares in 1925 to 3,7 million hectares in 1934.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown

Shifting cultivation, practiced earlier in Finland, was beneficial for grey alder (Alnus incana (L.) Moench). It can produce seeds early and the early growth of the seedlings is fast. Areas where shifting cultivation was intensive, the areas next to the fields were pure alder stands, next circle was Betula sp. dominated, beyond that could be found Scots pine (Pinus sylvestris L.), and finally Norway spruce (Picea abies (L.) H. Karst.). When shifting cultivation ended, Norway spruce became more common. Many young mixed stands had Norway spruce undergrowth and alder overgrowth. The aim of the study was to find out how the stands develop to spruce dominated stands, and how they should be managed.

The density of spruce undergrowth affects the further development of both spruce and alder. The number of alder stems decreases the faster the denser the spruce undergrowth is. Alder overgrowth slow down the early diameter and height growth of spruce compared to pure stands. Also the diameter and height growth of alder remains smaller in mixed stands. The basal area of spruce develops slowly in the beginning, increases significantly by the age of 30, and surpasses the growth of pure spruce stands in Oxalis-Myrtillus site type. Thus, Norway spruce do not suffer from growing in the undergrowth. In the first years, fast growing alder seedlings limits growth of ground vegetation and protects spruce seedlings from frost.  Later thinning or removal of alder benefits spruce growth. The density of spruce undergrowth decides how much alder can be leaved in the stand. If the spruce undergrowth is thin, more alder can be left in the stand.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown