The influence of survey errors and growth processes on stem distribution in young growth under old beech growth. Comparison of a close-to-nature beech stand in the Sihlwald, Switzerland and a virgin beech stand in the Uholka forest, Ukraine.

摘要

The stem distributions in natural regeneration under an old-growth beech stand in the Sihlwald forest reserve and in the virgin forest reserve Uholka (Ukraine) show conspicuous sinks around the 1,40 m height-class. Technical survey methods can accentuate the sinks but they are not the only reasons for their occurrence. Simulated models reveal that differing lengths of height shoots in a height class and thus the differing speed with which the stems grow through the height-class, can have a decisive effect on the stem distribution. Sample re-measurements in the Sihlwald showed big differences of length of the annual shoots in the different classes over the past three years. The sinks in the model do not exactly correspond to the observed sinks and we can therefore conclude that other reasons also play a role. Since the height growth varies greatly from year to year, sinks are only a passing phenomenon..