Features of Spore and Pollen Preservation in Permafrost-Affected Soils of Yakutia
2022
Lopatina, D. A. | Zanina, O. G. | Fedorov-Davydov, D. G.
The article presents the results of studying the spores and pollen preservation in soils of the permafrost zone in Yakutia (Kolyma Lowland, Bykovsky Peninsula, Yakutsk and its neighborhood). Data on the qualitative and quantitative composition of palynomorphs and on the patterns of their damage are discussed, and the mechanism of their cryogenic destruction is analyzed. Palynological residues with destruction of the chemical-biotic type (thinning of the walls, the formation of cavities as a result of the chemical action of microbes on them) are present singly or absent, which is probably due to the specificity of permafrost with a predominance of low temperatures throughout the year and a generally suppressed microbiological activity. Palynomorph damages of the physical type (ruptures and cracks) usually predominate. In samples from mineral horizons of loamy soils, the content of damaged palynological remains is 5–10%; in mineral horizons of sandy soil, it reaches 20%. In sandy soil, the content of unfrozen water films performing a cryoprotective role is low, and the palynomorphs are more susceptible to destruction by growing ice crystals during freezing. The large-size Gymnospermae pollen of Pinus and Larix is most susceptible to destruction. Damages are usually present on the dominant pollen of Poaceae and Betula sect. Nanae, as well as of Cyperaceae and Ericaceae. Few damage cases are characteristic of pollen grains of minor taxa: Salix, Duschekia, Asteraceae, Onagraceae, Ranunculaceae, Caryophyllaceae and of spores of Sphagnum and Bryales. There are no damages on pollen of herbs Valeriana, Polemonium, Artemisia, Chenopodiaceae, and Polygonaceae and on spores of Lycopodium, Diphasiastrum, Selaginella, and Polypodiaceae. The results can be used in the reconstruction of paleogeographic conditions for buried soils, as well as in the study of cryopreservation of biological objects in permafrost areas.
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