FUNGAL SPORES

	FUNGAL SPORES: Unicellular or multicellular, reproductive or distributional cells developing into a number of different phases of the complex life cycles of the fungi. Fungal spores can be readily classified by the Saccardian system, which relies on the number, shape, and placement of spore cells to classify the fungi imperfecti. Most fungal spores in pollen preparations probably are phaeospores (dark spores) of the fungi imperfecti, rather than ascospores, basidiospores, or spores of the lower fungi. However, repeating (asexual) spores of the basidiomycetes are very common in some sites. Wolf (1969) demonstrated that dark fungal spores are more resistant to acetolysis than clear ones. Examples of the importance of fungal spores in palynology include the forms Helminthosporium and Alternaria that are common in aeroallergy studies. The dung fungus Sporormiella is an indicator of herbivore density, and has been shown to increase in historic times after the introduction of grazing animals, and before 11,000 years ago -- prior to megafaunal extinction (Davis, 1987; Davis and Shafer, in press). In the American Southwest, the decay fungus Tetraploa is very abundant in historic sediments due to increased abundance of senescent plant tissue in freshwater marshes (Davis, 1995).
	The spores of various wheat and corn pathogens, notably Tilletia and the uredeospores of rusts and smuts are common in the historic period in southeastern Washington (Davis, et al., 1977). Thecaphora is a pathogen on Fabaceae and Caryophyllaceae that becomes common during the historic period in the California grasslands, perhaps due to the spread of the pathogen by over- grazing (Davis, 1992). More generally, dark, thick-walled fungal spores of the fungi imperfecti are common in soil samples, such as those often studied in archaeological palynology. These same forms occur in abundance equal to that of terrestrial pollen when soil is washed into aquatic basins by watershed erosion, particularly after fires or intense human disturbance (Bradbury & Waddington, ; Davis et al., 1977).
	References: Geoscience & Man, and Palynology: Morphology & Systematics / AASP Foundation Contributions Series 11 / AASP PALYDISK 2 Bradbury, J.P. and Waddington, J.C.B. 1973. The impact of European settlement on Shagawa Lake, northeastern Minnesota, U.S.A. pp 289- 308 IN: H.J.B. Birks and R.G. West, eds. Quaternary plant ecology Juhn Wiley and SOns, New York. Davis, O.K. 1987. Spores of the dung fungus Sporormiella: increased abundance in historic sediments and before Pleistocene megafaunal extinction. Quaternary Research 28:290-294. Davis, O.K. 1992. Rapid climatic change in coastal southern California inferred from Pollen Analysis of San Joaquin Marsh. Quaternary Research. 37:89-100. Davis, O.K. 1995. Pre-Columbian human impact on the wetlands of the Southwestern U.S.A. AASP 28th Annual Meeting, Oct. 10-14. Ottawa, Ontario, Canada. Davis, O.K., Kolva, D.A., and Mehringer, P.J., Jr. 1977. Pollen analysis of Wildcat Lake, Whitman County, Washington: The last 1000 years. Northwest Science 51(1): 13-30. Davis, O.K. and Shafer, D.S. in press. Sporormiella: an indicator of the Clovis-Folsom biomass collapse? In: Stanford, D. and Jodry, P. (Eds.) Smithsonian Series in Archaeological Inquiry. Wolf, F.A. 1969. Disintegration of Fungus Spores. Journal of Elisha Mitchell Scientific Society 85:92-94. Links Atlas of Beringia NOAA, UofWash. U Berkeley Buckman Lab photo

Owen Davis 12/99