ANALÝZA ZMĚN V PRODUKCI A ZDRAVOTNÍM STAVU SMRKOVÉ TYČOVINY V PLO 29, NÍZKÝ JESENÍK.

The aim of this work was to evaluate the development of production characteristics and healThstatus of young spruce stand in the area of the Nízký Jeseník Mts. (Czech Republic). Research was conducted in the period 2016-2018 on 12 sub-plots established in the spruce stand at the age of 19 years. Diameter and height increments and derived production characteristics were monitored along wiThdefoliation, biotic damage and mortality rates. In addition, a prediction of stand development was carried out using a linear regression model. Between 2016 and 2018, the decrease of the stand basal area was recorded from 24.7 to 24.1 m2/ha. Annual diameter increments slowed down from 0.5 cm to 0.4 cm and height increments from 0.59 to 0.24 m. Volume increments decreased from 6.86 to 3.12 m3/ha. Cumulative mortality reached 24.1% in 2018, which means an increase of 13.9% compared to 2015. Defoliation increased from 25.8% in 2016 to 30.5% in 2018. The terminal mortality factor causing the current dieback of mature spruce stands in the Northern Moravia is bark beetle (Ips sp.). In the case of younger stands, decline can occur as a result of the effect of phytopathogens, especially Armillaria sp. that fundamentally affects the functionality of the root system and disturbs an uptake of water and nutrients. This effect is currently intensified by drought episodes. Changes in the tree species composition aimed at increase of the proportion of improving and stabilizing tree species in combination wiThchemical amelioration are a way to preserve the production function of the forest on sites currently severely damaged. [ABSTRACT FROM AUTHOR]