Study of the Natural Flora of Hezar-Jarib Protected Area (Located in Mazandaran & Semnan Provinces, Iran)

Hezar-Jarib Protected Area is situated in the heights of the Alborz Mountains, representing a region of significant botanical richness and serving as a transitional zone between the Hyrcanian and Iran-Turanian (IT) vegetation areas. This area is a component of the Paband National Park, spanning across Mazandaran and Semnan provinces. Plant specimens were gathered during the periods of 2009-2010 and 2021-2022 across various growing seasons and were identified by using traditional methods of plant taxonomy with reference to botanical literature. This study documented 369 taxa of 323 species, encompassing 61 families and 226 genera. Dicotyledons constituted the largest group with 309 taxa (82.6%) followed by monocotyledons with 50 taxa (13.3%). The most abundant families were Asteraceae (51 species), Lamiaceae (33 species), Poaceae (28 species), Rosaceae (25 species), and Brassicaceae (24 species), which exhibited extensive distribution within the region. Among the collected samples, 39 species were found to be endemic to Iran with 24 species classified as having a low risk of extinction, 3 species as vulnerable, and 23 species as single-species genera. The study's analysis of life forms revealed the prevalence of hemi-cryptophytes (37.1%) due to the mountainous terrain followed by trophites (31.2%). Furthermore, in terms of chorology, 230 species (62.5%) were identified as belonging to the Iran-Turanian (IT) region, the Europe-Siberian (ES) region, or both.