Flora, Life Form and Chorological Study of Soil Seed Bank of Silk Tree (Albizia julibrissin Durazz.) Habitats in Forests of Mazandaran province

This study was investigated the above-ground vegetation and soil seed bank flora in three site of Albizia julibrissin Durazz. In Hyrcanian Lowland Forests (including Haloomsar, Anjilisra forests and Sisangan Box tree (Buxus hyrcanus Pojark) reserve). Aboveground vegetation was sampled by 68 plots of 400 m2 during late June and seed bank flora was studied by seedling emergence method. The result showed that there were 66 plant taxa belonging to 59 genera and 38 families in the extant vegetation of the studied eareas, while a total of 93 species, 82 genera and 48 families were represented in the soil seed bank.Lamiaceae, Poaceae and Rosaceae with 5 species (7.6%) were the most frequent families in the above-ground vegetation while in soil seed bank Asteraceae with 12 species (12.9%), Lamiaceae with 6 species (6.5%) followed by Cyperaceae, Fabaceae and Poaceae with 5 species (5.4%) were the most important families. Results also showed phanerophytes with 37.9% (25 species) and Euro-Siberian with 42.4% (28 species) in the Above-ground Vegetation floras and Hemicryptophytes 32.3% (30 species) and pluriregional regions elements 28% (26 species) were the most important biological spectrum and phytochorion in the seed bank floras, respectivly.From total of 118 plant species, the proportion of species that presented only in the above-ground vegetation, only in soil seed bank and in both of them were 25, 52 and 41, respectively. This condition not only explains low similarity between soil seed bank and above-ground vegetation and it also showed the importance of soil seed bank study for introducing more accurate capacity of plant biodiversity. our result also showed that Albizia julibrissin Durazz with the average seed density of 270 seeds/m2 are attending in 61% of total seed bank samples which it emphesizes the role of its seed bank as a suitable source for natural restoration of Albizia julibrissin in the Hyrcanian Forests