State of Scots Pine Plantations in Ploughed or Harrowed Reforestation Areas in Central Finland

1989

32 S.

10 Abb., 6 Tab., 2 Anh., 37 Lit. Ang.

Bandaufführung

2628

37202

The development of plantations established on ploughed or harrowed (disc trenched) sites in central Finland was examined in the study. Most of the examined plantations were 5-10 years old. The inventory covered 23 ploughed and 32 harrowed regeneration areas that were measured on moist or dryish upland sites in summer 1983. Circular plot method with sample plot sizes of 6 or 10 m2 sited along the inventory line was used. Information about the bordering stands was also collected during the plantation inventory work. In the examined reforestation areas there were about 1 100-1 300 living transplants/ha. Of these, 840-1 100 transplants were regarded as viable seedlings. The planting result was almost the same in ploughed and harrowed areas, but on the dryish upland sites it was better than on the moist upland sites. The number of living transplants varied considerably between different planting years. The planting result was extremely low in plantations established in summers 1976 or 1978 which were the driest and coldest years in the 1970's. The number of transplants varied also according to the efficiency of scarification (proportion of soil surface disturbed by scarification) and distance to the border stand. There were usually more transplants in the center of the regeneration area than near the forest border. Natural seedling regeneration depended a lot especially on the time since the site preparation, efficiency of scarification, distance to the border stand and quality of border stand. Part of the naturally regenerated seedlings were established prior to scarification but most of them were born a few years after scarification. Natural seedling regeneration continued longer on the ploughed areas than on the harrowed ones. The number of naturally regenerated seedlings was about 7 000/ha on the ploughed areas and about 4 400/ha on the harrowed ones. Most, over 80%, of these were spruces. There were hardly any hardwood seedlings developed from seed on these regeneration areas. Compared to earlier inventories carried out mainly in unprepared areas, the result of the whole forest regeneration chain was better. This was due to the natural seedling regeneration, which was so abundant because of scarification. The mean number of all types of viable seedlings was 1 520-1 970/ha. 45% of the viable seedlings had regenerated naturally. The future wood quality in these stands with stand densities lower than 2 000/ha at the seedling stage will not be very good.