The relationship between diameter at breast height and coppice production of Parrotia persica (Case study: Kheyrud forest)

Parrotia persica is one of the few species growing naturally in the northern forests of Iran. This specie is reproduced through asexual reproduction by coppice (shoot). This research was done to study the effects of DBH on sprouting and to select the best diameter classes regarding to asexual reproduction in experimental and educational forests of Kheyrud. Nitty nine 0.1 ha circular samples plots were randomly established. Trees were classified into three diameter classes, class1: 10-30 cm, class 2: 30-60 cm and class 3: more than 60 cm. Regeneration was separated into four classes with diameter 2-4, 4-6, 6-8, 8-10 cm. To compare the mean number of coppice in diameter classes, Analysis of Variance and Duncan tests were used with 95 percent confidence level. The results indicated that Parrotia persica trees in class 2 (30-60) had the highest number of coppices (10.8).The average number of coppices in diameter class1 ,2 and 3 and are 6.6, 10.8 and 6.5 per base, respectively. Healthy coppices with more diameters are better than other coppices.  The number of coppices with diameter 2-4 cm is higher than other classes, and class 2 (30-60) has the maximum number of coppices. The results of ANOVA showed significant difference in the average number of coppices with diameters 2-4, 4-6, 6-8, 8-10 cm. The results of this study indicated that diameters at breast height affect the asexual reproduction of Parrotia persica. To establish asexual reproduction of this species, the diameter class 30-60 cm is more important.