Title: Identification of land potential by seed banks under sheep grazing in the Icelandic highlands

The soil seed bank is an essential source for the natural restoration of degraded rangelands. This study assessed seed density and species composition of soil seed banks in plots where grazing had been excluded by fencing for six years and in control plots in Auðkúluheiði and Þeistareykir in the highland rangelands of Iceland. Soil samples were collected from 48 experimental plots at 0-10 cm depth. Emerged species from the soil seed bank (belowground) were compared with existing vegetation (aboveground). Only 48 seedlings from 15 species emerged from the soil samples. The results showed a negligible correlation between species richness in the aboveground vegetation and the number of seedlings that emerged from soil seed banks. The number of emerged seedlings did not significantly differ between fenced and control plots. However, the species richness of the soil seed banks in the non-fenced plots was higher than in fenced plots, and this was mirrored by higher species richness in non-fenced plots in the aboveground vegetation. The results of this study indicate that six years of grazing exclusion in the Icelandic highlands might not be long enough to drive differences in the soil seed banks, suggesting that grazing exclusion may not be an efficient short-term strategy to strengthen soil seed banks in rangelands that have been grazed for centuries.