Phytoliths in some grasses of Altai region from deferent ecological groups and life forms

The study investigated Poaceae phytoliths from the Altaisky Kray of Russia. This botanical study was performed to enable future paleoecological reconstructions in the region. We examined 17 species of grasses: 16 from the subfamily Pooideae ( Agropyron pectinatum, Agrostis gigantea, A. vinealis, Bromopsis inermis, Calamgrostis epigeios, Elymus exelsus, E. gmelinii, Elytrigia repens, Festuca pratensis, F. pseudovina, Koeleria cristata, Leymus angustus, L. dasystachys, Stipa capillata, S. korshinsky, S. pennata ) and 1 species - from the subfamily Panicoideae ( Setaria viridis ). Many species were analyzed in such detail for the first time. Phytolith extraction was based on the methods described by A.A. Golyeva. We ashed plant matter for 15 - 20 hours in a muffle furnace at 400 degrees Celsius. The material was examined with the help of an optical microscope. Phytoliths were counted in up to 200 individual forms. Phytolith production in plants was studied according to ecological groups and life forms. Grasses of five ecological groups were examined: xerophytes, meso-xerophytes, mesophytes, xero-mesophytes, and meso-hygrophytes. Plants of four life forms were examined: loose-sod and dense-sod grasses, long-rootstock grasses, and annual grasses. We used the life forms classification of I. G. Serebryakov; such analysis of phytoliths from various life forms of grasses was undertaken for the first time. We distinguish the following morphotypes: Trapeziform Short Cells, Trapeziform Polylobates, Trapeziform Sinuates, Rondels, Papillae, Saddles, Trichomes, Bilobate Short Cells, Crosses, Stomata, Bulliform (Fan-Shaped) Cells, Long cells with different textures (smooth, scrobiculate, echinate, sinuate) and other forms. As a result, we confirmed the specificity of certain morphotypes: Trapeziform Sinuates, Bilobate Short Cells and other. The difference between phytoliths of ecological groups and live forms was marked in grasses. Dense-sod and loose-sod xerophytes and meso-xerophytes produce mainly Trapeziform Short Cells and Rondels in combination with Trapeziform Sinuates, Smooth Long Cells and a small amount of Trichomes. Loose-sod grasses have more diverse sets of phytoliths. Meso-xerophytes, mesophytes and xero-mesophytes can produce Trapeziform Polylobates and a lot of Trichomess. Long-rootstock grasses produce large amounts of Trapeziform Polylobates and Trichomes and, sometimes, Trapeziform Sinuates. We conclude that Trapeziform short cells can help identify steppe communities, while Trapeziform Polylobates and Trichomes can help identify meadow and forest communities.

phytoliths, phytoliths analysis, grasses, ecological group, paleoecology