Spore and Pollen Analysis
Spore and Pollen Analysis
in botany, a method by which plants may be classified according to characteristic morphological features of spores and pollen grains. Spore and pollen analysis is possible owing to the vast number of spores or pollen grains produced by a single plant. The external coat of spores and pollen grains are usually stable and are almost never destroyed, even with petrifaction or fossilization.
Spore and pollen analysis is most commonly used in geology, geomorphology, and paleogeography—areas of study whose objects of investigation include sedimentary rocks, peat, and sapro-pel from which pollen and spores have been extracted by special means. The method is also used in archaeology, medicine, the study of staple commodities, and other branches of knowledge.
Spore and pollen analysis involves the identification by microscopic examination of fractions containing fossil remains. The presence of a vast number of spores and pollen grains makes it possible to determine not only taxonomic membership but also the ratio of spores and pollen grains. As a result, it is possible to determine the flora that existed at the time the rock was deposited and to assess the vegetation of the region based on the production, dispersal, and fossilization of spores and pollen grains.
Statistical evaluation leads to the identification of spore-pollen spectra or spore-pollen. The spore-pollen spectrum is the content, expressed by percentages, of pollen grains and spores of various taxa in a single test. The spore-pollen complex is the content, in percentages, of the sum total of pollen grains and spores in a sample of the quantitatively predominant pollen grains and spores. A paleofloristic, paleophytocenological, or paleoclimatic investigation of young, mainly anthropogenic, deposits requires a determination of spore-pollen spectra, since the pollen or spores found in very small quantities may belong to extant plant species whose ecological features may be important in interpreting the results of the analysis. For stratigraphic purposes it is often sufficient to identify the spore-pollen complexes of the test sample, especially in investigating ancient deposits; the fossil spores and pollen grains are classified according to an artificial morpho-graphic system.
Most valuable is the spore and pollen analysis of a series of samples from a cut, taken from successive depths of the deposit. This method makes it possible to trace changes in the flora during the course of sedimentary accumulation. In addition to composite numerical tables of the results of the analysis, special diagrams that graphically represent these changes are constructed. Rectangular-coordinate diagrams are also constructed, placing the depths from which the samples were taken along the vertical axis and the percentage composition of the constituents of a given sample along the horizontal axis. By joining the points by straight lines the participation of like components in the spectra is shown.
The founders of spore and pollen analysis in Russia were V. N. Sukachev and V. S. Dokturovskii. Originators of the method in Sweden included G. Lagerheim, L. Post, and G. Erdtman. In the 1930’s spore and pollen analysis was used by the Soviet scientists S. N. Naumova, A. A. Liuber, and I. E. Val’ts to study Paleozoic and Mesozoic coal. After the formulation by V. P. Grichuk of a dependable method for isolating fossil pollen grains and spores, spore and pollen analysis was used for investigating all types of sedimentary rocks.
Spore and pollen analysis made possible the establishment of artificial systems for classifying spores and pollen grains of extinct plants dispersed in ancient rock. The method also led to the standardization of the principles of taxonomy and nomenclature for such plant remains. The types of spore-pollen spectra (steppe, forest, tundra) that correspond to extant types of vegetation have been identified by Grichuk, and the spore-pollen spectra and complexes that characterize deposits of various ages in any given region were described by Naumova, Liuber, and I. M. Pokrov-skaia. Spore and pollen analysis has increased our understanding of the climate in past geological periods.
There are a number of newly developed methods of interpreting the results of spore and pollen analysis of anthropogenic sedimentary rocks and peats. M. I. Neishtadt constructed regional diagrams reflecting the development of vegetation in some regions of the USSR in the Holocene. The pollen grains and spores of many plant species have been described, and keys for identifying pollen grains and spores have been devised. These developments have been of great significance to plant taxonomy. The principles of pollen and spore dispersal and burial have also been studied.
REFERENCESNaumova, S. N. Spory i pyl’tsa uglei SSSR. Trudy XVII sessii Mezhdunarodnogo geologicheskogo kongressa. SSSR, 1937, vol. 1. Moscow, 1939.
Grichuk, V. P., and E. D. Zaklinskaia. Analiz iskopaemykh pyl’tsy i spor i egoprimenenie v paleogeografii. Moscow, 1948.
Pyl’tsevoi analiz. Moscow, 1950.
Neishtadt, M. I. Palinologiia v SSSR. Moscow, 1960.
Sladkov, A. N. Vvedenie v sporovo-pyl’tsevoi analiz. Moscow, 1967.
Erdtman, G. An Introduction to Pollen Analysis. Waltham, 1943.
Textbook of Pollen Analysis, 2nd ed. Edited by K. Faegri and J. Iverson. Copenhagen, 1966.
A. N. SLADKOV