Vegetation History Since the Mid-Holocene in Northeastern Iceland

The primary goal of this study was to gather paleoenvironmental data from the vegetation recordin istilfjorur over the last 6000 years in order to present a detailed paleoecological study of pre- and post-settlement vegetation history. Palynological analysis of peat cores collected near two abandoned farms in the Svalbarstunga Valley of the istilfjorur region of northeastern Iceland was used to reconstruct the midHolocene vegetation history and to distinguish climatic and anthropogenic impacts on terrestrial ecosystems since colonization. The first site, Hjlmarvk, is located along the coast of istilfjorur, while K is located 12 km inland. From 6430 to ca. 4500 cal BP, shrub tundra and birch woodland dominated the landscape. Between ca. 4500 and ca. 1170 cal BP, cooler and wetter conditions favored peatland species, while birch significantly declined. From 1170 cal BP to the present, grassland and peatland were prevalent. Birch woodland had virtually disappeared from the inland regions by 5810 cal BP and from the coast by 3450 cal BP. However, isolated trees persisted in certain areas. Following the initial Norse settlement of Svalbarstunga at about 1000 AD, the development of agriculture and sheep grazing promoted the spread of sedges and facilitated the introduction of new plant species. Ecological changes linked to the Norse landnm were more limited in Svalbarstunga than elsewhere in Iceland, where abrupt changes such as woodland clearance and erosion have been associated with human settlement. Moreover, as the region was inhabited since 1000 AD, we sought to distinguish the effects of climate and anthropogenic activities on vegetation succession. This paper also offers a regional perspective on the evolution of vegetation spanning the transition between coastal and inland zones in a unique region that has the distinction of having been part of the same land ownership system for over 1000 years.