Articles containing the keyword 'taimituhot'

The aim of the present study was to survey the occurrence of Otiorrhynchus nodosus Müller weevils and their significance for the natural regeneration of Scots pine (Pinus sylvestris L.). The study was carried out during summer 1982 at Inari in northern Lapland.

There were two sample plots, one situated in a Scots pine seed-tree area and the other, the control sample plot, in an area with a coverage of mountain birch (Betula pubescens subsp. tortuosa, now subsp. czerepanovii). A total of 177 Otiorhynchus weevils were caught. Movement of the weevils reached its climax in July. There were 86% more individuals in the seed-tree area than in the mountain birch area. No damage to the pine germlings or seedlings was not observed, although the situation could be different during the peaks of the veewil populations.

The PDF includes a summary in English.

• Suoheimo, E-mail: js@mm.unknown

The study was carried out in order to establish the possible influence of damage caused to the needles of Picea abies (L.) H. Karst. by the spruce spider mite, Oligonychus ununguis (Jacobi), and the growth of the damaged seedlings. The study was carried out in 1968–1970 by comparing growth of seedlings infected with spruce spider mite with that of seedlings where mites had been killed with acaricide (Eradex®). In the seedlings that had not been treated with acaricide, the number of wintering eggs were 60, 20 and 5 per shoot in the various years of the study. When the experiment was laid out, before planting and acaricide treatment, the seedlings were four years old, all seadlings were heavily infected, the number of wintering eggs being 100 per shoot. The growth of infected seedlings was 3, 20 and 15% smaller than that obtained for the seedlings which had been treated with acaricide.

The PDF includes a summary in English.

• Löyttyniemi, E-mail: kl@mm.unknown

In early spring 1968 it was noticed that the black grouses (Lyrurus tetris L.) was eating terminal shoots of Scots pine (Pinus sylvestris L.) seedlings in a tree nursery in Luumäki, Southern Finland. The terminal shoots were picked 1–4 cm from the top of the seedlings. In total some thousands of two-year-old seedlings were damaged. The depth of the snow was 10–15 cm deep and only the tops of the seedlings could be seen above the surface of the snow.

The PDF includes a summary in English.

• Löyttyniemi, E-mail: kl@mm.unknown

When the seed harvest of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) are low, pine and spruce buds are among the secondary food items of squirrel (Sciurus vulgaris L.) in Finland. In this study, conducted in Nokia in Southern Finland in 1962-1963, eating of pine buds by squirrel is described. The eaten buds in 15-years old Scots pine seedlings were recorded in two seedling stands.

According to the results, the squirrels selected the largest buds of the best seedlings in the studied stands. In over 50% of the cases the squirrels chose only the buds of the leading shoot, especially the terminal bud. In half of the trees, a side bud of the leading shoot continued the growth, which causes form defects in the trees. In 35% of the damaged trees, a lateral branch continued the growth. Well-growing seedling stands may be especially susceptible for damages caused by, for instance, squirrels.

The PDF includes a summary in Finnish.

• Pulliainen, E-mail: ep@mm.unknown
• Salonen, E-mail: ks@mm.unknown

Since 1954 studies have been carried out by the Department of Plant Pathology of Agricultural Research Centre on occurrence of low-temperature parasitic fungi in nurseries in Finland. This paper reports analysis of the damage caused by the fungus to Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seedlings.

In Southern and southwestern Finland, scarcely any damage caused by low-temperature parasitic fungi to coniferous seedlings was found. On the other hand, in Central, Eastern and Northern Finland, considerable injuries were present in the seedlings. The extent of damage varies between different localities and in a same location from year to year. The extent of damage is mostly dependent on snow cover which is heaviest in Central and Northern Finland. Damages are largest in wooded areas and in places where snow accumulates abundantly and remains until late in the spring.

The principal cause of winter damage to spruce seedlings is Hepotricia nigra (Hartig) which causes black snow mould. Depending on the amount of infestation, the damage can be limited to scattered groups or consist of large areas of dead seedlings. The fungus is unable to infect the plants during warm months of the growing season. The most damaging parasitic fungus in Scots pine is Phacidium infestans (Karst.) causing snow blight. The infestation varies from reddish-brown patches of infected seedlings to large areas of infected plants. Also, Botrytis cinerea has been determined from one- and two-year plants of pine and spruce.

In trials of chemical control by PCNB (pentachloronitrobenzene) gave nearly complete control of low-temperature parasitic fungi in one-year spruce seedlings. In addition, a compound of zineb (Dithane Z-78) gave similar results. Chemical control of the fungi is now common in the nurseries.

The PDF includes a summary in English.

• Jamalainen, E-mail: ej@mm.unknown

The aim of the study was to find out more about pine weevil (Hylobious abietis L.) injuries in Scots pine (Pinus sylvestris L.) seedling stands and their control by means of DDT. For this purpose, inventories were made of seedling stands established earlier. Control experiments were made on burnt areas by planting seedlings dipped in a DDT emulsion.

The results of the inventories show that injuries caused by pine weevils can, in certain circumstances, especially in seedling stands established by planting, cause the complete failure in artificial regeneration. The extent and quality of the injuries vary greatly according to planting method, treatment of the cutting area, age of the seedling stand, environmental factors, and weather conditions. The most extensive injuries occur in regeneration areas of old Norway spruce stands burnt after clear cutting and planted with Scots pine seedlings. Injuries are greater in seedling stands established by planting, especially after broadcast burning, than in seedling stands originating either from artificial or natural seeding. The quality of the patch for sowing or planting has a considerable effect on the quantity and character of the injuries: in a patch from which organic matter has been removed, injuries do not appear or they are slighter. Seedlings can be protected effectively and economically by dipping their tops up to the root collar, in a DDT emulsion before planting.

The PDF includes a summary in English.

• Nenonen, E-mail: mn@mm.unknown
• Jukola, E-mail: jj@mm.unknown

The article reviews the occurrence of damage causes by elk (Alces alces L.) in young Scots pine (Pinus sylvestris L.) stands established by direct seeding in the Ostrobothia region in Finland. The data was collected by random sampling, and consists of 110 sample plots in pine stands, established in 1930-1944.

Signs of elk damages could be observed in 20% of the stands. In more than half of the damaged stands pine seedlings were damaged by elk, on the rest of the stands the damage was targeted to hardwood saplings only. With the present density of elk population, the damage has an insignificant bearing upon the development of pine seedling stands in Ostrobothnia. The weaknesses of silvicultural state of the stands have been caused by other factors than elk.

Silviculturally weak stands were more liable to elk damage than strong ones. The occurrence of elk damage was more usual in stands with hardwood mixture than in pure pine stands. Especially goat willow, mountain ash and aspen, but also to some decree birch, seem to attract elk. Those factors that promote hardwood growth: fertility of the site, swampiness and the presence of seeding hardwoods in the area, increase the stand’s liability to elk damage.

The article includes an abstract in English and a summary in Swedish.

• Yli-Vakkuri, E-mail: py@mm.unknown

Finland has a long tradition of grazing cattle in the forests and common land. There are also reports of degradation of forests by grazing already in 1600th century. The aim of the survey was to study which positive and negative effects grazing has in forests.

The study concludes that grazing has caused considerable economic losses through damages to forests. In addition, woodland pastures cannot give the yields required in modern animal husbandry. The quality of woodland pastures have decreased after the woodlands used in slash and burn culture have become wooded.

Grazing has also some positive effects to forests. It increases the diversity of vegetation in the woodland pastures and spreads species to new areas. This is supported by the lists of species found in different woodland pastures. Cattle destroy large grasses like Calamagrostis, which may avail growth of tree seedlings in the pastures. Grazing can also prepare the site for tree seedlings. On the other hand, prolonged grazing destroys tree seedlings and prevents regeneration.

The article includes a German summary.

• Lampimäki, E-mail: tl@mm.unknown