Study of site quatity of Caucasian Alder (Alnus subcordala C. A. MeY.) in the Caspian Region (west of Mazandaran province)

In order to determine the site quqlity on pure and even- age stands of alnus subcordata, 56 sample plots of 500 m² area were selected in different diameter (age) classes and all of trees were studied in sample plots. Site index curves, based on dominant height/diameter(age) were complied for Caucasian alder.Numbre of trees varies from 82 to 1640 stem per hectare in differekt diameter (age) classes.The standing volume with 60 cm mean diameter breast height is estimated up to 720 m³/h. Height of dominant trees on the dominant diameter (age) with 35 cm at breast height differs from a lower limit of 20 and an upper limit of 32 meter

Determination of Beech (Fagas oricffiolis Lipsky) seeding cycle at caspian Forests of Iran (Kelardasht)

The research project of determining Beech seeding cycle was conducted at Kelardasht region of Caspian Forests. Thirty dominant Beech trees were selected for quantity and quality measurement. After soil and ground cover sampling and tree measurments, the trees were cut down and a disc sample was taken from each tree stump. The discs were analyzed at Division of Wood Science Labs of Research Institute of Forests and Rangelands to study the annual rings. The results showed that: 1- Fagus orientalis has two seeding methods, heavy and light. 2- The minimum age of seeding is about 30 years when is Often associated with light seeding. 3- The heavy seeding begins at age of 60 years. 4- At a same site, different seeding cycles were observed during the living period. 5- The light and heavy seeding  continues every 1-5 and 3-18 years, respectively. 6- It seems that natural regeneration depends on light seeding cycles beacause of their frequent occurance. 7- Forest management projects should be based on light seeding cycles rather than heavy seeding cycles. As a result, the harvesting period should be increased from 5 years to 10 or 15 years. 8- There was a relationship between annual ring growth rate and seeding methods as follows: a. If decrease rate of annual ring growth is less than 0.74 mm, there will not be seeding cycle. b. If decrease rate of annual ring growth is between 0.74 mm and 15 mm. then there will be light seeding cycle. c. If decrease rate of annual ring growth is more than 15 mm, there will be heavy seeding cycle

Study on growth and silvicultural analysis of young stand of Quercus castaneifolia C.A.M. in Neyrang forest, Nowshahr

Oak (Quercus castaneifolia C.A.M.) is one of the most important forest tree species in the Caspian region of Iran and every year huge lands are purely planted by it. The aim of the research was to study characteristics of an even-aged planted stand (25 years old, 1.2 ha) of the species and proper management which lead to suitable tree form in future. For this purpose, diameter at breast height (dbh) and total height of all the trees and volume of 30 sample trees were measured. Results showed that although tree plantation was made only by oak species, but the stand today consists of 10 species as follows: oak (85.2%), horn beam (7.9%), iron wood (0.7%) and other species, including velvet, Cappadocian maple, elm, alder, and lime tree (6.2%). Most of the trees were classified at three diameter classes, including 10, 15 and 20 cm. diameter and height increment for trees with average dbh and total height of 15.3 m. and 16.4 m, were 6 and 66 mm. respectively. Mean dbh and height increment rates were 0.6 and 66 cm per year, respectively. Mean volume increment was 5.13 silve per year per ha. It can be concluded that according to our findings and other similar research results that diameter growth of oak in Iran is faster than its growth in Europe and might be utilized at lower age stage for veneer industry. Furthermore, stand structure in respect to trees form and mixture rate was studied and its trend process into mixed stand was silviculturally discussed and analyzed