Dynamics of the health status of forest stands and its prediction on research plots in the Šumava Mts.

The paper summarises the evaluation of the health status dynamics of allochthonous spruce stands in the Modrava Forest District and of natural stands in the Plesný Forest District. Analysis is based on dendroecological reactions of particular tree individuals in the stand texture. The tree damage was evaluated annually (in the period 1997-2005), based especially on defoliation. The most tolerant were the natural and semi-natural, especially mixed forest stands with dominant beech in the Plesný Forest District territory, the least tolerant were the allochthonous secondary spruce stands in the Modrava Forest District area. The damage dynamics was limited by the insect (bark beetle - Ips typographus) pest activity. Ozone damage appeared much more often in 2002, compared to the year 1999. The most damaged species were sycamore and rowan tree.