The effect of geographical direction on plant density and diversity in Sardasht forests

The results showed that Q. infectoria Oliv, Quercus brantii, and Quercus libani oaks had the highest density in the north, south, and east directions, respectively. Hawthorn had the highest density per hectare in the eastern direction. Based on the results, species diversity in the southern direction has the highest value. Geographic direction has a significant relationship with species density and diversity. Based on the results of the present research, in order to carry out management plans, one should pay attention to the spread of species in geographical directions and take necessary measures based on that. Determining and comparing biodiversity in different forest communities is of special importance for accurate knowledge and forest management. This research was conducted with the aim of investigating the effect of geographical direction on species density and diversity in the Lilane oak forests of Sardasht in an area of about 28 hectares. First, a statistical network with dimensions of 45 x 45 meters was implemented in the region in a systematic random way. In this regard, 120 sample plots (30 sample plots for each geographical direction) were established in the research area and the geographical direction, number and type of trees were recorded. According to the density of species in the sample plots, the density per hectare was calculated, and to check and compare the biodiversity from the Simpson and Shannon-Wiener species diversity indices, the species richness was calculated from the Margalf and Ghanai richness indices. Peylo and Hill's uniformity indices were used for mechanistic and species uniformity. Biodiversity index values were determined using Past software. Then, the normality of the data was done using the Kolmogorov-Smirnov test, the homogeneity of variances was done with the Lune test, and the comparison of the averages in four geographical directions was done with the Duncan test in SPSS software. The results showed that Q. infectoria Oliv, Quercus brantii, and Quercus libani oaks had the highest density in the north, south, and east directions, respectively. Hawthorn had the highest density per hectare in the eastern direction. Based on the results, species diversity in the southern direction has the highest value. Geographic direction has a significant relationship with species density and diversity. Based on the results of the present research, in order to carry out management plans, one should pay attention to the spread of species in geographical directions and take necessary measures based on that.