THE STUDY OF NATURAL REGENERATION STRUCTURE IN ARASBARAN FOREST (SOTANCHI REGTON)

Arasbaran forest (Gharadagh) that located in the north of Ahar City (eastern Azarbaijan province) are very important beacause of ecological condition and specific fauna and flora. These non commercial forests including species such as Oak, Hornbeam, Walnut, cherry, elm and maple trees. The understory species are: Cornus mas, Viburnum lantana, V. oppulus, Prunus. sp and in destructive area Paliurus spina-christi, Rosa. sp, crataegus. sp and Rubus. sp replace by main species. This study was achieved in order to finding natural regeneration structure in Sotanchi experimental forest (that is one subregion of Kalibarchi watershed). In order to fulfill this research, 36 primarily circle plots (0.1 ha) was measured. After calculation of standard deviation, 139 main plots were indicated in a systematic random method. Also inside of every main plot, a qubic microplot (0.0004 ha) was measured (nested plot). All species with diameter at breast height (d.b.h) from zero to 7.5 cm was measured in the main plots and also site factors, landscape and deforestation effects recorded. In every microplot, trees origin (high or coppice system) with d.b.h under 7.5 cm. Were indicated. Also the number of sprouts was counting and their average height calculated. This study indicated that regeneration structure in Arasbaran forest is in high and coppice system but coppice system is further. The main forest types that detected in this region are: Quercu-carpinetum and carpinetum. The most regeneration was occurred in north and north-west slopes under closed and semi-closed canopy because of appropriate humidity, temperature and light condition. Among all regeneration, the rate of Horn beam was 31.7%, Oak 29.3%, maple 8.2%. Cherry 1.4% and other species (Cornus mas, viburnum lantana, juniperus. spp) were 29.4%. The rate of seed regeneration was 28.7%. The average number of sprout on every stump was six their average height was 3.7 m. Oak and Hornbeam had the most regeneration power among existing species. The average height of sprouts in Maple, Hornbeam, Oak and Ash trees was very much but in Cherry trees was under 1 m.