Statistically significant minimum pollen count in Quaternary pollen analysis; the case of pollen-rich lake sediments

Abstract

The statistical reliability of a pollen count in representing the true composition of modern and fossil pollen assemblages depends on the minimum number of pollen grains counted. In palynological literature this number varies between b150 and N1000, but very few studies have probed the question using robust statistical approaches. Here, we use the Pearson-Brown Prophecy formula and apply it to different fossil pollen counts from two large lake systems in Iran to calculate the minimum terrestrial and total pollen count necessary to obtain a reliable representativity of pollen assemblages. Our results surprisingly show that a pollen count of b150 is sufficient to achieve a reliability of 0.90 with no additional significant information obtained when counting more pollen. If the upland vegetation reconstruction is important, then terrestrial pollen counts as low as 67 could be sufficient. It seems that the statistically significant pollen counts are site-specific and vary between different environments and even within the same type of environment. We suggest that this value should be calculated for each pollen site so that the pollen analysts can more efficiently manage their time when counting pollen slides.

Deep-Water Syn-rift Stratigraphy as Archives of Early-Mid Pleistocene Palaeoenvironmental Signals and Controls on Sediment Delivery

“…Dinoflagellate cyst counts vary considerably and a minimum count criterion for some samples could not be met with a mean count of 34 (varying from 1 to 212). Most pollen samples were counted until at least 250 grains to exceed the ranges typical for validity in Quaternary lacustrine studies (Djamali & Cilleros, 2020). However, four samples were deemed barren for pollen, dinoflagellates and spores, with an additional sample showing a very low count and poor preservation of material (Supplementary Table S4).…”

Continuous presence of proto-cereals in Anatolia since 2.3 Ma, and their possible co-evolution with large herbivores and hominins

“…The pollen percentages were calculated on a Pollen Sum (PS) including all plants except Filicophytes, Bryophytes, Algae, and NPP. For each sample, pollen counting was carried out up to 300 to 400 grains (phanerogams alone) and then continued over the whole slide for rare taxa 52 . At Acıgöl, the mean PS varies from 3025 grains (all pollen, spores and NPP included) to 558 grains per sample (all pollen, without spores and NPP).…”

Lost Gardens: From Knowledge to Revitalization and Cultural Valorization of Natural Elements

“…For example, there are inherent risks when using pollen analysis to reconstruct the history of cultivated crops in gardens. The risk can arise from a variety of factors e.g., differential preservation, as well as differential pollen production and dispersal by different species [74,141].…”