Dynamic early Holocene vegetation development on the Faroe Islands inferred from high-resolution plant macrofossil and pollen data

Abstract

Vegetation dynamics during the earliest part of the Holocene (11,250"10,250"cal yr BP) have been reconstructed from a lacustrine sequence on Sandoy, the Faroe Islands, using detailed plant macrofossil and pollen evidence. The plant macrofossils suggest the initial vegetation was sparse herb and shrub tundra, with Salix herbacea and open-ground species, followed by the development of a denser and more species-rich arctic heathland after 11,150"cal yr BP. Despite high pollen values for Betula nana, macrofossils are rare. The bulk of the macrofossils recorded are S. herbacea and Empetrum leaves with numerous herb taxa and an abundance of Racomitrium moss. Conditions start to change around 10,800"cal yr BP, with increased catchment erosion and sediment delivery to the lake from ca. 10,600"cal yr BP, and a transition to alternating Cyperaceae and Poaceae communities between ca. 10,450 and 10,250"cal yr BP. This vegetation change, which has been recorded throughout the Faroes, has previously been interpreted as a retrogressive shift from woody shrubs to a herbaceous community. The detailed plant macrofossil data show the shift is the replacement of an Empetrum arctic heathland by grassland and moist sedge communities. These taxa dominate the modern landscape.