Aim The objective of this paper is to explore the relationships that exist between vegetation and modern pollen rain in the open, largely treeless landscape of subarctic Greenland. The implications of these results for the interpretation of fossil pollen assemblages from the time of the Norse landnám are then examined.Location The study area is the sheep farming district of Qassiarsuk in the subarctic, subcontinental vegetational and climatic zone of southern Greenland (61°N, 45°W). Between c. ad 1000-1500 this region was contained within the Norse Eastern Settlement.Methods Detrended Correspondence Analysis (DCA) of harmonized plantpollen data sets is used to compare plant cover in 64 vegetation quadrats with pollen assemblages obtained from moss polsters at matching locations. Presence/ absence data are also used to calculate indices of association, over-and underrepresentation for pollen types.Results Good correspondence between paired vegetation-pollen samples occurs in many cases, particularly in locations where Salix glauca-Betula glandulosa dwarf shrub heath is dominant, and across herbaceous field boundaries and meadows. Pollen samples are found to be poor at reflecting actual ground cover where ericales or Juniperus communis are the locally dominant shrubs. Dominant or ubiquitous taxa within this landscape (Betula, Salix and Poaceae) are found to be over-represented in pollen assemblages, as are several of the 'weeds' generally accepted as introduced by the Norse settlers.Main conclusions Due to their over-representation in the pollen rain, many of the Norse apophytes and introductions (e.g. Rumex acetosa and R. acetosella) traditionally used to infer human activity in Greenland should be particularly sensitive indicators for landnám, allowing early detection of Norse activity in fossil assemblages. Pteridophyte spores are found to be disassociated with the ground cover of ferns and clubmosses, but are over-represented in pollen assemblages, indicating extra-local or regional sources and long residence times in soil/sediment profiles for these microfossils. A pollen record for Hordeum-type registered in close proximity to a field containing barley suggests that summer temperatures under the current climatic regime are, at least on occasion, sufficient to allow flowering.

Peat cores were taken from eight primary and one secondary raised bog sites throughout the United Kingdom in order to determine the pathways of succession between the microform (hummock, ridge, lawn, hollow, and pool) plant communities of the mid to late Holocene. All of these sites have undergone drainage and/or cutting in the recent past, at least. The plant communities were reconstructed by using plant macrofossil analysis, and they are defined primarily by the dominant species of Sphagnum. While plant macrofossils may be used to infer hydrological conditions, an alternative proxy, using testate amoebae, was utilized. This group of organisms was used to avoid circular arguments when relating the vegetation changes to hydrological events. Consequently, a conceptual model of late Holocene succession on British raised mires is constructed that elucidates succession between the microform plant communities according to changes in the water table depth, its stability, quality, and physical disturbance of the vegetation cover. The general sequence of ombrogenous communities was elucidated to be, with increasing height above the water tables, S. cuspidatum and S. auriculatum Ͼ Sphagnum sect. Cymbifolia taxa Ͼ Sphagnum sect. Acutifolia taxa Ͼ a return of Sphagnum sect. Cymbifolia taxa Ͼ non-Sphagnum mosses.A major pathway toward degradation of the mire is apparent in modern times, and recovery is typically via a phase of dominance by S. tenellum prior to the establishment of either S. magellanicum or S. papillosum. Although this disturbance is of a large magnitude, it was found that equable or more severe perturbations to the water table had occurred in the past, especially at coastal sites where marine regression led to the establishment of Sphagnum-poor communities dominated by Calluna and Eriophorum vaginatum. The longterm persistence of hummock-hollow vegetation communities is demonstrated, but the appearance of persistent, more homogeneous phases suggests that this surface topography is not always well developed.