Dept. of Forestry, Faculty of Natural Resources, Tarbiat Modares University, Mazandaran, Noor, Iran
Composition and structure of a three-storied Fagus orientalis-dominated forest was investigated in the Caspian forests, north of Iran. Circular sampling plots of 1000 m2 occupied by advance growth and natural regeneration were randomly chosen where the initial cuttings (with shelterwood aim) were performed. Abundance of species at different growth stages and quality of seedlings and saplings were registered and basal area and standing volume determined. The measurements were carried out before the first shelterwood cutting (in 1974) and after the last shelterwood cutting (2004). The results after 30 years (in 2004) revealed that frequency, basal area and standing volume significantly enhanced for beech and reduced for hornbeam but did not statistically differ for alder, maple and other species. Sapling and thicket groups were observed in parts of the investigated site and where the mature trees were not felled. Generally, the research area was converted into an irregular uneven-aged 2-4-storied forest, owing to recruits, advance regeneration, aged trees and small and large pole groups maintained through the forest.