Pollen productivity estimates for the reconstruction of past vegetation cover in the cultural landscape of southern Sweden

Abstract

Pollen productivity estimates (PPE) are one of the critical parameters for a quantitative recon struction of past vegetation from fossil pollen records. Modern pollen and vegetation data were collected in traditional landscapes of southern Sweden to derive PPE for the most characteristic plant taxa. The 42 selected sites are assumed to be good analogues of historical to prehistorical grasslands. A sampling method of vegetation, designed to produce plant abundance data in different distance classes, allowed the use of distance-weighted plant abundance around the surface pollen sites. PPE for 11 herb taxa and Juniperus communis were estimated by extended R-value (ERV) models, using the distance-weighted plant abundance and surface pollen data. Results using three ERV submodels, data sets from open and semi-open landscapes, and two distance-weighting methods are generally consistent. The herb taxa analysed have higher PPE than Poaceae except Cyperaceae and Compositae (sub-family) Cichorioideae. Calluna vulgaris, Rumex acetosa type, Juniperus communis and Plantago lanceolata have the highest PPE. Most of the common tree taxa in the region produce 6–8 times as much pollen per unit area as Poaceae. The present set of PPE covers most of the common herb taxa of northwest Europe and will be useful for simu lating pollen dispersal and deposition in heterogeneous landscapes of open and forested vegetation, which will help in future research project design and in the interpretation of fossil data.