We investigated regeneration patterns and dead wood dynamics in high altitude natural Norway spruce Picea abies forest in the Tatra Mountains, Polish Western Carpathians, and used dendrochronological cross-dating to asses the age of fallen logs. We compared the exact time since tree death with physical features reflected in a 5-degree classification of the decomposition stage. In more decayed logs where wood samples were impossible to cross-date we used the maximum age of saplings growing on logs as an indicator of minimum log age. The total volume of dead wood on the forest floor was ca 60 m³ / ha. Dead wood covered ca 5% of the forest floor. The log ages were for class A (least decayed) -- up to 4 yr, for class B: 8-44 yr and for class C: 44-115 yr. The minimum age of the most decayed classes D and E was estimated to 50 and 60 yr, respectively. One year-old seedlings were present on logs of all decay stages except on fresh windbreaks and windthrows of class A. The highest number of seedlings was found on logs in decay classes C and D which indicates that the middle stage of decomposed wood is the best substrate for germination. The successful cross-dating of over one hundred years old spruce logs is an evidence that some portion of fallen logs may escape fast deterioration even in species normally regarded as not resistant to decay.
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