Analysis of composition and biodiversity of understory plants in natural and reforestation stands of western Hyrcanian(Case Study: Ramsar Sang Poshteh)

The aim of this study was to evaluate the vegetation cover of alder and broadleaved coniferous forests of alder, maple and oak and compare it with natural forest in Ramsar Ridge. 96 sample plots of 400 square meters were collected by regular random sampling.The bio-spectrum of plants was determined based on the vegetative forms of Rankier and the geographical distribution of species based on the Zohary method. The results showed that 30 plant species belong to 23 families, most of which belonged to Fabaceae and Poaceae, Rosaceae. In terms of biological form, hemicryptophytes and cryptophytes were dominant with 68.73% of vegetative forms. The study of geographical distribution of plants in the region showed that the plant elements of Europe-Siberia constitute the most of the plant elements in the study area. Evaluation of plant biodiversity in forest stands showed that Simpson and Shannon Wiener diversity indices and Ghanaian Margalph index were not statistically significant and Kamenergo and Smith Wilson richness indices and homogeneity indices were not significantly different. Showed. Biodiversity of woody species regeneration in Simpson species diversity indices was highest in Alnus subcordata C.A. Mey and lowest in Cupressus Semprvienes L.Var. horizontails.