جستجوی مقالات مرتبط با کلیدواژه "توده کمتر دست خورده" در نشریات گروه "جنگلداری"

In order to investigate the effect of traditional utilization on the diversity and composition of woody species diversity in the western oak forest, two disturbed and less disturbed stands were selected with similar physiographic and floristic conditions. Therefore, 30 circularly shape plots with 1000 m2 surface area were established based on random-systematic sampling with 50×50 m network dimensions. In each sample plot, the frequency and type of woody species were recorded in the prepared sheets of inventory. The average Margalaf species richness indices, Pielo evenness, Shannon-Weiner and Simpson species diversity were calculated in each plot and normalized by Kolmogorov-Smirnov test. To test the significance of the difference between the mean of indices, t-student test was used for normal data and Mann-Whitney U test for abnormal data. Detrended Correspondence Analysis (DCA) was used for ordination of the woody species samples. The results of the study showed that the means of richness and diversity indices in the disturbed stand were significantly lower than in the less disturbed stand; however, the mean of evenness index did not show any statistically significant differences between two stands. High correlation of first axis of DCA proves the importance of destructive factors, such as cutting, branching, frequency of copping, grazing, and qualitative factors, such as basal area and number of trees. These factors plays an important role in differentiation of the forest stands.