Relation between establishment and distribution of Acer velutinum Boiss. with soil physical and chemical properties and topographic factors in Caspian forest: a case study of Nav Asalem district/ Guilan

This research was carried out in Asalem/Guilan province where، Acer velutinum show preferred establishment and distribution. In this research، soil chemical and physical properties and topographic factors effected on establishment and distribution of Acer velutinum was investigated to determine the most important ecological factors. Using tree type and topographic maps، the sampling plots were taken randomly in appropriate distribution sites of Acer velutinum. In each sample plot، aspect، slope، elevation، tree species، diameter of each tree and soil samples were taken and then the most important soil properties were analyzed. Regeneration of tree species was also taken in center of each main plot in micro-plot. The results showed that C، N and water holding capacity (WHC) have positive and significant correlation with distribution of Acer velutinum and among topographic factors، north aspect also showed this correlation. C، P، WHC، sand content and elevation showed positive and significant correlation and Ca، Mg showed negative correlation with regeneration of Acer velutinum. The final results of this research showed that productive sites with fertile soils are the main factors for establishment and distribution of Acer velutinum.