Studying changes in the biodiversity and formation of plants at the heights of western Dena mountain range

The protected region of Western Dena is located in the southern part of Zagros mountain range in Kohgilouyeh and Boyer Ahmad province. Western Dena is one of the richest areas of Iran in terms of biodiversity. The purpose of this study is to investigate the changes in the biodiversity, arrangement, and formation of plants at the heights of Dena mountain range. Samples were collected following a random-systematic data collection procedure. Thirty plots were identified using the least level of species method. The coverage percentages of each species as well as the dominant ones were determined in each sample plot. Information regarding the height, direction, the percentage of the slope was recorded in each sample plot. The floristic investigation of 30 sample plots indicated that 212 sample plants belonging to 24 plant families exist in Western Dena region, out of which 41 are endemic, 12 are rare, 1 is vulnerable, and 7 belong to one-genus species. The results revealed that the heighest range for the growth of Phanrophytes, Comfites, and Geophites was 3150-2242, 3350-4050, and 2514-2926 m respectively. The Hemicrytophytes and Trophites grow in all of the heights. The most influential factor in the degree of plant coverage in the region was the height. The slope percentage was in the second place regarding the significance. There are four arrangements of trees, bushes, pulvinate plants, and herbaceous plants in the region. In addition, there are 117 species of Hemicryptophytic vegetation (55%), 44 Therophytic vegetation forms (21%), 17 Chamephytic vegetation forms (8%), 17 Geophytic vegetation forms (8%), and 17 vegetation species of Phanerophytes.