Effect of light on quantitative and qualitative characteristics of hornbeam seedlings (Case study: Korkrood forest, Mazandaran)

Hornbeam is the most frequent species in forests of northern Iran. This paper aims to study the relationship between gap size and some quantitative and qualitative characteristics of hornbeam seedlings. For this purpose Khanikan district in Korkrood forest was selected in northern Iran. Four sizes of gap were selected based on silvicultural definitions including: area with less than 200 m², 200 to 500 m², 500 to 1000 m², and larger than 1000 m² and in each gap, 4 subplots each 2 m² were laid out. The current study was made in 2 phases: 1) study on light intensity using fish-eye camera, and 2) quantitative (including collar diameter and height) and qualitative characteristics of hornbeam seedlings. The obtained result showed that the intensity of light changed between 2 and 70 percent in different gaps and different locations of the gaps. The number of hornbeam seedlings increased with a relative increase in the light intensity initially and then decreased. Collar diameter and height of seedlings didn’t show significant differences among different light intensities. The number of seedlings was reduced significantly in the gaps larger than 500 m2. The best qualitative condition and the maximum number of hornbeam seedlings were observed in the gaps smaller than 200 m2.