This paper reports a country wide study on the health condition and its short term dynamics in the most threatened middle-aged-to-old-growth oak stands. The field measurements and observations were carried out in the period 2001-2004, covering 52 stands in 18 forest districts. Except of the complete survey of each stand, a total of 1560 permanently marked trees were subject to detailed measurements and assessment, both conducted during the growing season and at the leafless stage, in order to comprehensively describe the variety of tree vitality aspects. It is concluded that the health status of the majority of stands covered by the present study are threatened, both in terms of their development and stability.

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