Decline of Norway spruce in the Krkonoše Mts.

Abstract

The paper summarizes results from the analyses of Norway spruce (Picea abies [L.] Karst.) stands managed by the Forest Administration in Horní Maršov, Krkonoše National Park (KRNAP), which are affected by decline and by yellowing of the assimilatory apparatus. Forest stands included in the analyses were aged 10-80 years and originated from both artificial and natural regeneration. Analyses of root systems were combined with analyses of soil chemical properties and assimilatory organs, weather conditions and emissions. The analyses showed that affected trees had small and malformed anchoring root systems with a lower number of horizontal roots and a lower number of fine roots of lower vitality (high proportion of dead fine roots), which penetrated only through the uppermost humus horizons. Root systems of affected trees are infested by the honey fungus (Armillaria sp.), which colonizes anchor roots. Neither root nor bole rots were detected so far.

Keywords

• decline
• fine roots
• honey fungus
• malformation
• norway spruce
• root system