Phytolith morphotypes of woody plants and their preservation in soil in the warm temperate humid zones of China.

Studies of the morphotypes, production and preservation of phytoliths in soils provide a theoretical basis for paleovegetation reconstruction. However, there is a lack of systematic studies of the phytoliths of woody plants in the warm temperate humid zones, which greatly limits the application of phytoliths in paleovegetation reconstruction in this environmental context. In this study we analyzed the phytoliths of 211 plant samples (81 leaf samples, 73 branch samples, 57 bark samples) and 30 topsoil samples from the warm temperate humid zones of China. The results demonstrate that while most of the leaf samples contained phytoliths, only a few of the branch and bark samples did so. In terms of phytolith concentration, the sample types were ordered as follows: bark samples > leaf samples > branch samples. In this study the phytoliths in woody plants were classified into10 categories and 22 sub-categories, and the results of detrended correspondence analysis (DCA) showed that elongate dentate and blocky morphotypes were closely associated with Picea ; elongate cavate and margin-cuneiform morphotypes were closely associated with Larix ; acute bulbosus and hair base morphotypes were associated with Morus , Broussonetia and Diospyros ; and elongate psilate, elongate attenuate, and sclereid morphotypes were associated with Quercus , but these types are not unique to Quercus. The topsoil woody phytolith assemblages contained four types of broad-leaved phytolith (tabular, tabular sinuate, sclereid, epidermal phytolith), and three types of coniferous phytolith (blocky, elongate dentate, elongate tabular). The ratio of the total of broad-leaved phytoliths to the sum of broad-leaved phytoliths and coniferous phytoliths is useful for discriminating broad-leaved forest from coniferous forest. Overall, the results confirm the usefulness of phytoliths as indicators of woody plants in the warm temperature humid region in China, and they demonstrate the potential of woody phytolith assemblages for paleovegetation reconstruction. [ABSTRACT FROM AUTHOR]