Quantity and decay stages of coarse woody debris in old-growth subalpine spruce forests of the western Carpathians, Poland

The amount and decay stages of dead wood and the residence time of logs was studied in old-growth spruce-dominated stands in the Tatra and Babia Gora in the western Carpathian Mountains in Central Europe. The DBH of living trees and snags as well as the dimensions of logs (with a minimum diameter of 10 cm) were measured on nine sample plots with a pooled area of 4.3 ha. For the logs, the decay stage was identified according to an eight-level decay classification. Dendrochronological cross-dating was applied to 107 wood samples of logs to determine the time since death. The average volume of living trees was 454 m(3)/ha and the volume of coarse woody debris (CWD) averaged 191 m(3)/ha. The noted volume of CWD was higher than volumes reported from previous studies in the Carpathian Mountains. On average, CWD made up 30% of the total volume (living plus dead) and varied between 49% and 21% for the stands. The average age of logs for decay class 1 was 13 years and 24, 28, 38, 45, 38, and 60 years for decay classes 2-7, respectively. Considerable variation of time since death between decay classes was probably due to a variable time while dead trees remained standing as snags.