Root system emergence and health condition in Norway spruce (Picea abies (L.) Karst.) affected by yellowing of assimilatory apparatus in the region of the Krušné hory Mts

Abstract

The paper analyses the decline of Norway spruce stands over a region operated by the Forest Administration in Horní Blatná (Krušné hory Mts) and its causes. Root system analyses made in 238 trees (age 10-117 years, Forest Altitudinal Vegetation Zones 6 and 7, modal podzol) showed that all trees affected by yellowing of their assimilatory apparatus had a smaller root system, worse root pattern distribution, root systems malformed into a tangle, smaller rooting depth and lower biomass and vitality of fine roots. Until an age of about 10 years, trees at good health condition are those, which have created a large superficial root system. From an age of about 20 years, healthy trees are those, which have created a large anchoring root system with anchors reaching into the Bs horizon. Impaired vitality induced in affected trees invasion of the honey fungus causing the infestation of individual root system branches (namely anchors), and reducing the size and hence the functionality of the root system.