DISTRIBUTION AND FRACTIONAL COMPOSITION OF BELOWGROUND SPRUCE BIOMASSAND LENGTH IN BIOSPHERE-RESERVE-POLANA

The results of root biomass research of spruce ecosystem in Pol'ana Bi osphere Reserve are reported. The investigation of below-ground tree b iomass and its length was done by means of destructive analysis of sam ple trees. The total below-ground biomass of the main forest stand rep resents 65.7 t.ha(-1) in term of dry weight. The greatest portion of t his biomass is occupied by stumps (31 %) and thick roots with diameter above 10 cm (39 %). One third of the overall below-ground biomass fal ls to other diameter classes. From the view of stability and physiolog y fine roots included in the first diameter fraction play important ro le - their amount is 1.3 t.ha(-1). The length of the roots decreases w ith the raising diameter. The most substantial root length occurred in the first diameter class (O < 0.5 cm) - 538 km.ha(-1) and represented 88 % of all spruce ecosystem root length. The roots in the second dia meter class (0.6-2.0 cm) represent about 10 %. Each next diameter frac tion contains about 0.5 %.