Soil Pollen Analysis

Abstract

SummaryAcidic soils (pH below 5.5) may contain a great deal of pollen through the profile, and the floristic composition of this pollen may vary greatly in samples from successively greater depths.Various attempts have been made in the past to interpret pollen diagrams from soils, but they have usually broken down through the application of methods of interpretation which are only applicable to properly stratified materials such as peats or lake sediments. Once it is appreciated that downwash of pollen through the soil confers on each species a depth distribution pattern characteristic of its history on the site, broad conclusions about the vegetative history of a site can frequently be drawn.The preservation of pollen depends on the biological activity of the soil, which is closely correlated with pH. Soils which have only been decalcified recently will have a short pollen record, perhaps only a few centuries, but intrinsically base‐poor parent material may permit preservation for several millennia.

Galilee Blooming: First palynological and archaeological data from an Early Byzantine Cistern at Horvat Kur

“…High percentages of indeterminant palynomorphs, usually >50%, and low pollen concentration are signs of differential preservation, and general loss of pollen grains is due to oxidation, biological agents such as bacteria and phycomycete fungi, and high pH (Bryant et al 1994, Bryant andHolloway 1996). Those processes including the vertical transport of palynomorphs through sediments via water (downwash) or by animal activity (bioturbation) are comparable to processes observed in terrestrial soils (Dimbleby 1961;Davidson et al 1999;Gavin and Brubaker 1999). Consequently, the pollen concentration in archaeological contexts, especially in dry soils in arid regions, is often too low to achieve a precise portrait of the vegetation, the record is usually greatly influenced by anthropogenic disturbances and alteration of palynomorphs has often led to overrepresentation of more resistant pollen types (Fish 1989, see references in Lebreton et al 2010).…”

Pollen degradation in mangrove sediments: A short-term experiment

“…As mentioned by Dimbleby (1957), an alkaline environment is not ideal for pollen preservation. The pollen numbers can be very low in sediments with a pH greater than 5.5 (Dimbleby, 1961). In other mangroves, a high pH value of the sediments leads to a poor fossilization potential of the mangrove pollen (Grindrod, 1988;Wang and Chappell, 2001), while in terrestrial forests, a decrease in pollen concentrations is associated with an increase in soil pH.…”

Surface pollen and its relationship to vegetation on the southern slope of the eastern Qilian Mountains

“…Oxidation, the pH value of soil, aridity, organic matter content and microorganism are the external factors that influence pollen preservation. Dimbleby (1957;1961) thought that the soil pH value is the most important factor that determines the pollen preservation. He found that when pH is higher than 5.5, the pollen concentrations decrease abruptly.…”