SILVICULTURAL EFFICIENCY OF STRIP-SHELTERWOOD FELLING IN PINE STAND OF MID-TAIGA SUBZONE OF KARELIA

The protective forests in Karelia are concentrated mainly (80 %) around water objects. More than 50 % of these forests are presented by Scotch pine (Pinus sylvestris L.) stands. Modern practice of forestry prefers the simplified felling types oriented on use of natural renewal potential of pine forests because artifical regeneration on stony soils are very complex. On a site of the strip-shelterwood felling (intensity of 35 %) in an uneven-age pine stand of bilberry type in 9 years after the felling three transects consisting of plots of 5 × 5 m with a total length of 1150 m across the clear-cut strips were established for an assessment of natural renewal. Under forest canopy pine undergrowth is presented poorly. At the general frequency of 15 % and average height of 1.2 m its density is less than 0.2 thousand tress per ha, and its condition does not give a hope to expect of growth improvement. The condition of spruce (Picea A. Dietr.) undergrowth is better: its frequency – 36 %, height – 2.4 m, and density – 0.32 thousand tress per ha. On the cutted strips the pine frequency are 31 %, density and frequency of spruce and birch (Betula L.) remained almost without changes; the participation of an aspen (Populus tremula L.) and willow (Salix L.) are increased sharply. The strip-roads are covered by willow weed (Chamaenerion angustifolium (L.) Scop.), under the influence of which density and frequency of the conifers is twice lower. On the whole, the frequency and average height of a pine in the middle and at the edges of cutted strips are close. The executed felling did not provide the renewal of coniferous species sufficient for formation of a new forest stand, though emergence in recent years of the small undergrowth of a pine allows to count on his further quantitative increase. The executed assessment of increase in a radial growth of trees on cores showed his insignificance. The obtained results and literary data convince of obligatory need of a scarification of the soil surface during the strip-shelterwood felling execution.