Title: Comparison of different vegetation restoration practices: the case of Gunnarsholt, south Iceland

Iceland is a fragile northern ecosystem where anthropogenic activities in conjunction with highly erodible volcanic soils and a cold, moist climate have caused severe land degradation. The degraded land and the slow natural recovery demand effective reclamation treatments. In this study the main purpose was to identify the most successful restoration treatment for degraded land at the study site and also to assess the effect of different restoration practices on soil organic matter and vegetation biomass. The study area consisted of reclamation sites in Gunnarsholt, South Iceland. In this study, I compared different restoration treatments. The different restoration treatments were: 1) control, 2) sown grass seeds and fertilizer applied in 2013, 3) sown grass seeds and fertilizer applied in 1962–1975, and 4) fertilizer applied in 1991. In each treatment I measured vegetation biomass, vegetation cover of each cover group (grasses, herbs, shrubs, dwarf shrubs, sedges, mosses, litter, lichens, fern, and bare ground) and counted the number of species. In addition, I measured soil organic matter and soil bulk density in each treatment. The results showed that the biomass and vegetation cover in fertilizer applied and sown seeds and fertilizer applied in 1962–1975 treatments were higher than on degraded land. Also, bulk density and soil organic matter were higher with fertilizer treatment than on degraded land. I concluded that the fertilization treatment was most effective for improving the degraded land.