Novel methods of estimating relative pollen productivity; a key parameter for reconstruction of past land cover from pollen records

Fang, Yiman; Ma, Chunmei; Bunting, M. Jane

Abstract

Reconstructing land cover from pollen data using mathematical models of the relationship between them has the potential to translate the many thousand pollen records produced over the last 100 years (over 2300 radiocarbon-dated pollen records exist for the UK alone) into formats relevant to ecologists, archaeologists and climate scientists. However, the reliability of these reconstructions depends on model parameters. A key parameter is Relative Pollen Productivity (RPP), usually estimated from empirical data using ‘Extended R Value analysis’ (ERV analysis). Lack of RPP estimates for many regions is currently a major limitation on reconstructing global land cover. We present two alternatives to ERV analysis, the Modified Davis Method and an iteration method, which use the same underlying model of the relationship between pollen and vegetation to estimate RPP from empirical data, but with different assumptions. We test them in simulation against ERV analysis, and use a case study of a problematic empirical dataset to determine whether they have the potential to increase the speed and geographic range of RPP estimation. The two alternative methods are shown to perform at least as well as ERV analysis in simulation. We also present new RPP estimates from southeastern sub-tropical China for nine taxa estimated using the Modified Davis Method. Adding these two methods to the ‘toolkit’ for land cover reconstruction from pollen records opens up the possibility to estimate a key parameter from existing datasets with less field time than using current methods. This can both speed up the inclusion of more of the globe in past land cover mapping exercises such as the PAGES Landcover6k working group and improve our understanding of how this parameter varies within a single taxon and the factors control that variation.

Citation

Fang, Y., Ma, C., & Bunting, M. J. (2019). Novel methods of estimating relative pollen productivity; a key parameter for reconstruction of past land cover from pollen records. Progress in physical geography, 43(6), 731-753. https://doi.org/10.1177/0309133319861808

• Journal Article Type: Article
• Acceptance Date: Jun 11, 2019
• Online Publication Date: Jul 24, 2019
• Publication Date: Dec 1, 2019
• Deposit Date: Jun 19, 2019
• Publicly Available Date: Jun 19, 2019
• Journal: Progress in Physical Geography
• Print ISSN: 0309-1333
• Electronic ISSN: 1477-0296
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• Volume: 43
• Issue: 6
• Pages: 731-753
• DOI: https://doi.org/10.1177/0309133319861808
• Keywords: Extended R-value method (ERV); Iteration Method (IM); Modified Davis Method (MDM); Pollen analysis; Reconstruction of landcover from pollen data; Southeast China
• Public URL: https://hull-repository.worktribe.com/output/2010235
• Publisher URL: https://journals.sagepub.com/doi/full/10.1177/0309133319861808