Development and health condition of the root system of Norway spruce (Picea abies (L.) Karst.) in the region of the Jeseníky Mts

Abstract

The paper analyzes development and health condition of the root systems of visually healthy and declining Norway spruce (Picea abies (L.) Karst.) trees at three sites of the Jeseníky Mts. Affected by the decline were trees of all age classes. Unlike naturally regenerated trees, all of the analyzed declining trees had their root systems malformed into tangles. The root systems of all the declining and the majority of healthy trees were infested by honey fungus (Armillaria sp.). The declining trees did not show any nutritional deficiency. Up to the Forest Altitudinal Vegetation Zone 4 (GFT 4B), spruces do not grow in the ecological optimum. After weakening due water shortage, the root systems become infested by honey fungus which induces root, stem base and bole rots. As a result of malformations, the declining trees in Forest Altitudinal Vegetation Zones 7 and 8 (forest type group 7S, 8S) have always significantly smaller root systems colonized by honey fungus and characteristic lower rooting depth. Honey fungus does not affect root, stem base or bole rots. The declining trees have less biomass, lower vitality and suffer from mycorrhizal infection of fine roots.