Effects of Ecological Factors on the Distribution of Artemisia melanolepis and Artemisia aucheri in Southeast of Sabalan, Iran

Aims: This study aimed to assess the relationship between environmental variables (physiographic and soil) and distribution of Artemisia melanolepis and A. aucheri to find the most effective factors on the distribution of these species southeast faced slopes of Sabalan Mt., in the northwest of Iran. Materials & Methods: 4 sites with the distribution of the genus Artemisia (site with the presence of Artemisia species) and four sites with the absence of 2 Artemisia species were selected. In each site, five transects with a length of 100m (50 one square meter plots) with random- systematically method was established, and the density of Artemisia species and land cover parameters (including percent of litter, stone and gravel, total canopy cover, and bare soil) were recorded in each plot. Seventy-two soil samples were collected from 0-15cm depth. Sampling was conducted from May to July 2015 in the pick growing stage. One-way ANOVA and Canonical Discriminate Analyses (CDA) were used for data analyses. Finding: The ANOVA and mean comparison results showed that all selected environmental variables except total canopy cover and bare soil had significant differences (p<0.01). The results of CDA showed that two functions justified 76.6 and 23.4 percent, respectively, and 100% of the data variance. Finally, 97.3% of the grouped cases were classified correctly. The elevation, potassium, slope, aspect, stone, and gravel were primarily the most effective factors in the first function in the discrimination of the Artemisia species. Some parameters such as sand, silt, electrical conductivity, total neutralizing value, water-dispersible clay, organic matter, pH, total canopy cover, litter, and bare soil were second effective factors in the discrimination of sites and distribution of Artemisia species. Conclusion: Although physiography and soil variables affected the establishment of Artemisia species and showed significant differences between the three discriminated groups; however, the degree of importance of physiographic parameters is more significant than soil factors.