The interpretation of fen carr pollen diagrams: The representation of the dry land vegetation.

Binney, HA; Waller, MP; Bunting, MJ; Armitage, RP

Abstract

Deposits of fen carr origin are frequently used in pollen-based studies, including those where the primary objective is reconstructing the Holocene history of dry land vegetation. However, there have been few studies of modern pollen–vegetation relationships in these circumstances. Here as an aid to the interpretation of fossil assemblages we determine the distribution of pollen derived from dry land sources within areas of fen carr. In particular, we examine the effect distance from the dry land/fen carr edge has on the pollen representation of the dry land vegetation components. Data on vegetation composition and modern pollen samples (from moss polsters) were collected from a series of sample points within two areas of fen carr and adjacent drier woodlands in Norfolk, UK. The spatial distribution of the pollen derived from dry arboreal elements is explored through trend surfaces and plots of pollen representation against distance away from the dry land/fen carr edge. The pollen assemblages from the fen carr sample points reflect and can be used to infer the composition of adjacent dry woodland areas where they are dominated by the relatively high pollen producers Quercus and Betula. The presence of dry taxa that occur away from the dry land/fen carr edge is difficult to detect even if these taxa are generally regarded as over-represented in the pollen record (e.g. Pinus sylvestris). Arboreal elements that are present in the vegetation close to the edge of the dry land show a general declining trend in pollen representation within the first 80 m of fen carr. Factors influencing this pattern include the variable input of pollen from wetland taxa and the spatial irregularity of the dry land/fen carr edge. Pollen recruitment into fen carr systems resembles other closed canopy sites. Palaeo-sites situated within c. 80 m of the dry land/fen carr edge afford the opportunity to reconstruct vegetation at the stand scale. However, adjustments need to be made for differential pollen dispersal, for example, the local presence of Fraxinus excelsior and Sorbus-type can only be detected within c. 20 m of the dry land edge. The interpretation of pollen sequences must also allow for changes in the position of this edge through time.

Citation

Binney, H., Waller, M., Bunting, M., & Armitage, R. (2005). The interpretation of fen carr pollen diagrams: The representation of the dry land vegetation. Review of Palaeobotany and Palynology, 134(3-4), 197-218. https://doi.org/10.1016/j.revpalbo.2004.12.006

• Journal Article Type: Article
• Publication Date: May 1, 2005
• Deposit Date: Oct 8, 2007
• Journal: Review of Palaeobotany and Palynology
• Print ISSN: 0034-6667
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 134
• Issue: 3-4
• Pages: 197-218
• DOI: https://doi.org/10.1016/j.revpalbo.2004.12.006