Vegetation patterns, pollen deposition and distribution of non-pollen palynomorphs in an ice-wedge polygon near Kytalyk (NE Siberia), with some remarks on Arctic pollen morphology

In ice-wedge polygon mires, small-scaled microrelief of ridges enclosing small depressions results in a short-distance vegetation mosaic. The correct recognition of these landscape elements in palaeoecological studies of peat sections in order to reconstruct their patterns and dynamics requires insight in the short-distance relationship between vegetation and pollen deposition. This paper presents an analysis of pollen surface samples in a high-resolution (1 m) transect across an ice-wedge polygon near Kytalyk (NE Siberia), including a discussion on the morphology of some critical pollen types and non-pollen palynomorphs (NPPs). We found a strong correlation between vegetation and surface elevation and a fair correspondence between pollen deposition and vegetation. Distribution of NPPs reflects surface elevation well, with algal spores dominating deep spots and testate amoebae prevailing on higher spots. Peak pollen/spore values unrelated to high species coverages (e.g. of Salix, Betula, Sphagnum, Poaceae) indicate that single plants within a population may cause the bulk of the pollen production. The absence of pollen of taxa with an important presence in the vegetation (e.g. Utricularia) must be attributable to low pollen productivity. Distributional patterns point at pollen transport by water in the polygon troughs/depressions. Our study shows that Arctic pollen records mainly reflect short-distance vegetation patterns. Palaeosequences consequently allow accurate reconstruction of local microtopography and its dynamics, but should not be over-interpreted in terms of changing (over)regional vegetation patterns and associated drivers.