Estimates of‘relative pollen productivity’ and‘relevant source area of pollen’ for major tree taxa in two Norfolk (UK) woodlands

Surface sample pollen assemblages and vegetation data collected from two East Anglian fen carr sites with adjacent dry woodland belts are analysed to estimate the relevant source area of pollen (RSAP) and the relative pollen productivity (RPP) values for the major canopy trees. The‘relevant source area of pollen’ is found to be on the order of 50-150 m, comparable with but slightly greater than estimates for forest hollow contexts in dry woodlands. Estimates of pollen productivity relative to Quercus are then compared with published values from south Sweden. Betula and Corylus values are similar, but some values estimated for taxa characteristic of wetter habitats, and therefore competitively advantaged in the fen carr system (Alnus, Salix and Fraxinus), are substantially higher at one or both sites. The results suggest that palaeoecological records from fen carr systems should be interpreted as reflecting predominantly local vegetation signals once the tree canopy is established.