ИСТИНА

Although phytolith analysis was first developed in Germany, i.e., within the temperate zone, it is now in practice most widely applied within the subtropics and tropics due to the presence of a greater diversity of phytolith-forming plants resulting in a greater morphological diversity of phytoliths in the southern regions, which generally simplifies data interpretation by phytolithologists. Phytolith analysis in the temperate zone has several limitations. For example, it is impossible to apply a ratio of photosynthetic pathway groups of C3/C4 for the reconstruction of past climates, because all native plants of the temperate zone belong to the C3 group (while the C4 group is only represented by several recently introduced, mostly cultural plants). There is a similar problem with analysing the oxygen isotopic composition of phytoliths. Another limitation concerns research into the origin of cultural plants, as there is not even one that has originated from the temperate zone (as opposed to, e.g., rice from China and maize from Latin America). There are more limitations in applying a generally accepted classification, e.g., by Twiss et al. (1969), which is designed for prairies of the Great Plains (USA), where most phytoliths are formed within short cells of grasses (pooid, chloridoid and panicoid shapes). The temperate zone is dominated by forest communities with diagnostic assemblages of phytoliths formed within long cells (diverse trichome and elongate shapes). For that reason, it is impossible to use some of the generally recommended indices, e.g., an aridity index (which is a ratio of chloridoid to the total count of pooid, chloridoid, and panicoid phytoliths). There a similar problem with the use of international nomenclature, where short cells are classified in detail, but all trichomes are found in a single group and, therefore, it is necessary to provide a complicated and lengthy description for each diagnostic feature of a certain trichome phytolith. However, all the above-mentioned complications and limitations do not hinder the development of phytolith analysis in the temperate zone. On the contrary, it is widely applied in paleoenvironmental reconstructions that have led to interesting and often outstanding conclusions. It is fair to say that some limitations are, in fact, advantageous. For example, the fact that all cereal crops are introduced grass species provides possibilities for the confident identification of ancient arable soils, where characteristic ‘dendroid’ phytoliths of such grasses are present, while no such shapes exist in plants of the temperate zone. This serves as a basis for reconstructions of ancient trade routes, e.g., the presence of rice phytoliths in a cultural layer of an ancient settlement is indicative of its trade with the south-east regions. Diagnostics of plant communities on the basis of specific shapes and sizes of trichome and elongate phytoliths has been developed by the author, widely applied for many years and proved to be reliable in the temperate zone. The author hopes that the international nomenclature will soon be supplemented by the simplified terminology on the specified groups of phytoliths. The forthcoming article by the author will focus on a high informative value of phytolith analysis applied in the temperate zone with specific examples given and existing terminological problems described. Phytolith analysis progressively develops in Russia as a prospective method in paleoenvironmental reconstructions and archaeological research.