Structural Analysis of Flora Composition in Altitudinal Gradient of QezelOzan - Kosar Altitudes rangelands, Ardabil province

The aim of this study was to investigate the structure of flora composition in the elevation profile of 937-2162m a.s.l. over 29 Km in the QezelOzan to the altitudes of Kosar county rangelands. Eight habitats and in each three 100 to 500m transects with 10 plots varied from 1 to 25 m2 were selected. Species were collected from the plots, and life forms, growth types and their geographical distribution and conservation were determined. Results show that 32 families, 101 genera and 146 species are distrbuted at the selected areas. Asteraceae families with 39 species (27%), Poaceae with 18 species (13%), Fabaceae with 13 species (9%), Astragalus with 8 species (48.5%) and Centaurea with 5 species (42.3%) are the most important elements of the flora. Spermatophyta with 1 species, angiospermae dicotyledoneae with 27 families, 82 genera and 124 species, and angiospermae monocotyledoneae have 4 families, 18 genera and 21 species. Respectively, the highest and lowest ratio of the family to the genera is at 1583-1683m 1:3.27 and 2139-2162m 1:1.92; the ratio of the family to the species is at 1583-1683m 1:3.91 and 1635-1677m 1:2.11; and ratio of the genera to the species is at 1568-1609m 1:1.30 and 937-965m 1:1.03. For bs with 105 species (72%) is the dominant growth type and trophytes with 62 species (43%) is the most abundant life form. Sixty nine species (47%) belong to the Iranian-Turanian region. Also, 14 native species of Iran, 8 low risk species and 2 vulnerable species are distributed at the study area.