Down dead wood in a montane beech forest stands on Deshat mountain. 4. Decomposition of down dead wood

Abstract

This study focuses on decomposition of down dead wood (logs and branches) was studied in a montane beech (Fagus sylvatica) forest on Deshat mountain (Mavrovo National Park), North Macedonia. The decomposition of down dead wood was followed through decay classes and the dynamics of different chemical compounds (C, Ca, Mg, K, Na, Zn, Fe, Mn and Cu). Down dead wood was classified into five decay classes. The concentration of analyzed elements usually shows increase (accumulation) from the second to the fourth decay class and decrease towards the last decay class (release). Only K and Ca showed steady increase of concentrations during the decomposition.

Wood density also correlated well with the concentration of elements. Concentrations of C, Ca, Fe, Na and Cu tend to decrease exponentially with density. In the case of K and Mg a two-stage pattern was observed.

The average age within decay classes was estimated with a simple exponential model (derived from literature data) that explains dependence of age-wood density dependence in beech. We estimated that decay classes D2, D3, D4 and D5 show average age of 17.6, 21.0, 32.5 and 54.9 years. The calculated decomposition constant (k) for logs is 0.034 which shows slow decomposition processes of coarse down dead wood.