Flora, life form and chorological study of soil seed bank in Sisangan box tree (Buxus hyrcanus Pojark) Forest Reserve

The present study involves the soil seed bank flora of the Sisangan Box tree (Buxus hyrcanus Pojark) reserve by using seedling emergence method. 150 soil samples were collected during late June and early November by hammering a hollow metal frame 400 cm2 to a depth of 5 cm. Results showed 67 species، representing 63 genera and 38 families germinated from soil seed bank. 45 species belonging to 28 families and 59 species belonging to 32 families were recorded in June and November soil seed bank respectively. The largest families were Asteraceae (7 species، 10. 5%)، Lamiaceae (6 species، 9%)، Poaceae (5 species، 7. 5%) and Rosaceae (4 species، 6%) which compromised 32. 8% percent of the total species in the soil seed bank. Results also showed that Hemicrptophytes (28. 4%) and Euro-Sibria elements (23/9%) were the most important biological spectrum and phytochorion respectivly in the soil seed bank of Sisangan forest. From the total number of species recorded in seed bank، 30 species (44. 6 %) were found only in the seed bank and never observed in above-ground vegetation. In this regard، seeds of 10 woody species including Albizia julibrissin، Ficus carica، Morus alba، Diospyrus lotus، Celtis australis، Gleditsia caspica، Buxus hyrcana، Ulmus minor، Zelkova carpinifolia and Carpinus betulus were found in the soil seed bank، from which only 6 species were able to produce persistent soil seed bank. This condition confirmed low similarity between above-ground vegetation and persistent soil seed bank and it also reiterated the importance of soil seed bank study for introducing more accurate capacity of plant biodiversity.