Scientific publications

Ball-rooted planting stock (BRPS) has been increasingly used in Russia for reforestation of felled sites. In Karelia, the forest plantation ratio cultivated by ball-rooted planting stock in 2004 was 24 % of total planting. The work objective is to assess the performance of pine BRPS in different types of forest growth conditions. The surveys covered 35 planted sites:
8 sites located in the northern taiga and 27 – in the middle taiga. In the northern taiga subzone the basic attrition of seedlings was recorded in the sites of felled crowberry-cowberry and crowberry-bilberry pine stands in the first three years after planting. The cause of mortality of pine seedlings was the large pine weevil, Hylobius abietis L., injuries and snow blight (phacidiosis). In the middle taiga in the first decade the pine seedlings in the sites of felled cowberry pine stands showed high seedling percent – over 80 %. The establishment rate in the sites of felled bilberry pine and spruce stands was lowered by the large pine weevil on drained loamy sand soils, and by drowning of the saplings planted in microdepressions left by scarifiers in loamy and moist loamy sand sites. Survival under these conditions was further deteriorated by suppression by herbaceous vegetation. In some sites there are about 38 % of planted pines were damaged by pine shoot moth, Evetria turionana, resulting a lower height increment. One of the sites with 6-year-old crops featured crooked trunk. Soil excavation showed the heavily distorted root systems of the plants. Presumably, the reason was a long stay of the seedlings in the sites of completion of growing. Conservation of plantation older than 10 years ranged widely – from 0 to 88 %. It mostly depended on soil fertility and the quality of silvicultural tending. Planted pine prevailed in the young stands only at the heavy cleaning sites. Thus, timely and proper tending of pine plantations at all stages is a pre-requisite for high-productive cultivation of coniferous stands.