Underground Biomass of an Adult Norway Spruce (Picea abies (L.) Karst.) Population

1991

S. 865-888

3 Lit. Ang.

Unselbständiges Werk

200062063

The International programme Man and Biosphere (MAB) UNESCO, which is aimed at forest protection and regeneration, involves also research into processes of development, growth and production of forest tree populations under anthropic influences. In this connexion, special attention has been paid to our dominant species, Norway spruce (Picea abies (L.) Karst.). The present paper deals with underground biomass analysis of the adult Norway spruce generation from the locality of the Olomucany Research Pedagogical Station, Faculty of Forestry, University of Agriculture, Brno. Five 123-year-old spruce sample trees were analysed by means of excavation of complete root systems according to the cardinal points, soil layers, location and root thickness. At an average, thick roots appear mostly on the northern and southern sides in the soil layer from 20 to 40cm. The thinnest roots grow, for the main part, on the western side in the upper soil layer. The 123-year- old adult spruce population exhibits the total biomass weight of 748.232t. ha-1, of which the underground biomass occupies 21%, from the total dry weight of 374.117t. ha-1 i.e. 19% and from the total volume of 847.677 Kubikmeter. ha-1 i.e. 22%. The comparison of 4 spruce populations aged 25, 52, 68 and 123 years indicates that the weight of underground biomass when fresh and when dry represents from 9 to 21% being on the lower limit at young age. This relation ranges from 12 to 22% in volume. The data obtained are of good use for understanding the architecture of roots and their biomass composition to increase the vitality and stability of spruce stands by effective silvicultural treatment.