Compilation of relative pollen productivity (RPP) estimates and taxonomically harmonised RPP datasets for single continents and Northern Hemisphere extratropics

Abstract

Abstract. Relative pollen productivity (RPP) estimates are fractionate values, often in relation to Poaceae, that allow vegetation cover to be estimated from pollen counts with the help of models. RPP estimates are especially used in the scientific community in Europe and China, with a few studies in North America. Here we present a comprehensive compilation of available northern hemispheric RPP studies and their results arising from 51 publications with 60 sites and 131 taxa. This compilation allows scientists to identify data gaps in need of further RPP analyses but can also aid them in finding an RPP set for their study region. We also present a taxonomically harmonised, unified RPP dataset for the Northern Hemisphere and subsets for North America (including Greenland), Europe (including arctic Russia), and China, which we generated from the available studies. The unified dataset gives the mean RPP for 55 harmonised taxa as well as fall speeds, which are necessary to reconstruct vegetation cover from pollen counts and RPP values. Data are openly available at https://doi.org/10.1594/PANGAEA.922661 (Wieczorek and Herzschuh, 2020).

Holocene plant diversity dynamics show a distinct biogeographical pattern in temperate Europe

“…New pollen productivity estimates for one of the study regions were available (White Carpathian forest steppe; Kuneš, Abraham, Werchan, et al, 2019), but their applicability outside the region is uncertain. Therefore, we used averaged pollen productivity values for the Northern Hemisphere (Wieczorek & Herzschuh, 2020), which we expected would provide robust estimates suitable for extrapolation into the past. We divided pollen counts of trees by corresponding pollen productivity values (see Appendix S2).…”

“…On the other hand, the present boreal forests (Felde et al, 2016), and the Early Holocene forests in our study area, host(ed) several high pollen producers (Pinus, Betula), which likely decrease the detection probability of rare pollen taxa. Our analysis (Appendix S6) shows that after removing this bias by using robust pollen productivity estimates for trees (Wieczorek & Herzschuh, 2020), the adjusted modern pollen assemblages no longer show significant differences in diversity between forested and open sites. This result indicates a reduction in the effect of local high pollen producers and the manifestation of a shared regional pollen pool.…”

Supplementary material to "European pollen-based REVEALS land-cover reconstructions for the Holocene: methodology, mapping and potentials"

“…The number of selected RPP values (n) for Poaceae included in the three synthesis is larger than the total number of RPP (tn), i.e. n = nt + 1 in our synthesis and those by Mazier et al, (2012) and Wieczorek and Herzschuh (2020). This is because the study of Bunting et al, in 2005(Bunting et al, 2005 S3).…”

“…From 2012 onwards, these RPP values have been used in numerous applications of the LRA's two models REVEALS and LOVE (LOcal Vegetation Estimates) (Sugita, 2007a(Sugita, , 2007b) to reconstruct regional and local plant cover in Europe (Cui et al, 2013;Fyfe et al, 2013;Mazier et al, 2015;Nielsen et al, 2012;Nielsen and Odgaard, 2010;Trondman et al, 2015). Recently, Wieczorek and Herzschuh (2020) published a synthesis of the RPPs available for the Northern Hemisphere; it includes new mean RPP values for Europe that were produced independently from the synthesis we present here. Therefore, we compare our mean RPP values for Europe with those of Wieczorek and Herzschuh (2020) and discuss causes for dissimilarities.…”

“…Recently, Wieczorek and Herzschuh (2020) published a synthesis of the RPPs available for the Northern Hemisphere; it includes new mean RPP values for Europe that were produced independently from the synthesis we present here. Therefore, we compare our mean RPP values for Europe with those of Wieczorek and Herzschuh (2020) and discuss causes for dissimilarities.…”