In Southern Finland Scots pine (Pinus sylvestris L.) is mainly sown on Vaccinium and Myrtillus-type sites. The material for the study was collected by measuring sample plots in pure, even-aged pine stand that had been sown. The sample stands had been thinned from below.
The volume of the stands was roughly the same as that of repeatedly thinned pine stands. The cubic volume of sown pine stands is 65–90%, varying according to age, of that of natural-normal pine stands. The current annual volume increment of stands on Myrtillus-type was 8–9 m3/ha at age of 20–30 years. The peak was reached at age of 35 years with 9 m3/ha, in the following years the increment is about 8 m3/ha until the age of 60 years. On Vaccinium type sites increment reaches 6–7 m3 level at age of 30 years, and attains the peak of 7 m3/ha at the age of 45 years. Annual increment was in young and middle-aged Myrtillus-type stands about 10% greater, and on Vaccinium-type stands 15–20% greater than in natural-normal pine stands.
The total volume increment in 70 years old Myrtillus-type stands was 580 m3/ha over bark, and in 80 years old Vaccinium-type stands 520 m3/ha. The total removal on Myrtillus-type sites totalled nearly 350 m3/ha in sown pine stands up to 70 years of age, and 280 m3/ha on Vaccinium-type stands. The total yield in sawn timber per hectare rises up to 6,300 cubic ft in a 70 years old stand on Myrtillus-type stands, and 5,300 cubic ft in Vaccinium-type stands. In conclusion, the volume and increment development of managed pine stands established by sowing up to 70–80 years of age is largely the same as in repeatedly thinned pine stands, but the structure and yield offer greater advantages. The investigation demonstrates that, in the case of Scots pine, sowing is an advantageous method of regeneration. Sowing is an advantage especially in the cases where natural regeneration is uncertain and slow.
The PDF includes a summary in English.