Silvicultural characteristics of Oriental beech (Fagus orientalis Lipsky) regeneration under different RLI and positions within gaps

Abstract

Summary This study was carried out in an unmanaged compartment of the Caspian beech forest in Iran. Eleven gaps having a long north-south axis and with Oriental beech saplings <1.30 m tall were selected. Two transects, each 2 m wide, were laid along the longest (N–S) and shortest (E–W) axis of each gap. Five sample plots, each 4 m 2 , were established: one at the centre and one at each edge. Qualitative and quantitative characters of saplings with a diameter at breast height (d.b.h.) less than 7.5 cm were determined in the sample plots. One hemispherical photograph was taken in each of the 55 plots using a fisheye lens to study the status of light in the gaps and the relationship between silvicultural characteristics of saplings and relative light intensity (RLI). Light intensity parameters were processed by Gap Light Analyzer (GLA) V.2 software. Analysis of variance was performed using SPSS software for quantitative characteristics and chi-square test for qualitative characteristics. Comparisons of averages for quantitative parameters were made by using a Tukey test. Results showed that RLI varies from the gap centre (18.1 per cent) to edges (9.6 per cent in west, 10.5 per cent in south, 12.1 per cent in north and 14.6 per cent in east). We found no significant difference in numbers of beech saplings across RLI levels, but there was some evidence that beech regeneration developed best with a RLI between 10 and 15 per cent.