Testing the reliability of pollen-based diversity estimates
Rarefaction analysis is a common tool for estimating pollen richness. Using modern and fossil pollen data from the Canadian Arctic and Greenland, we examine the effects of pollen concentration (grains/cc) and evenness (the distribution of species abundances) on palynological richness. Our results show that pollen richness and concentration have a strong negative correlation at low pollen concentrations. There is a positive correlation between pollen evenness and richness, although the strength of this relationship is difficult to determine. Rarefaction analysis on samples of low concentration or high evenness is likely to lead to pollen richness being less underestimated than on samples of high concentration or low evenness. These findings corroborate theoretical research on these issues.
KeywordsPollen analysis Rarefaction Diversity Pollen concentration Evenness Paleoecology Arctic
We are grateful to the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) and the Natural Sciences and Engineering Research Council of Canada (NSERC) for financial support. We thank Tom Olszewski, Pim van der Knaap, André Viau, and an anonymous reviewer for valuable comments. Pollen counts for the Abernethy Forest core were obtained from the European Pollen Database; Hilary Birks kindly provided the associated concentration data. Any errors, misinterpretations, or omissions are ours alone.
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