Characteristics of broadleaved woody phytoliths and their preservation in soils in the mid-subtropical zone of China

Background: and aims Phytolith analysis is a promising tool for paleovegetation reconstruction. However, compared with grass phytoliths, there are few studies that have classified the phytoliths of trees. Therefore, reliable definitions of phytolith types in woody plants and studies of representative woody phytoliths in soils are needed to provide an improved basis for reliable phytolith-based vegetation reconstruction. Methods To explore the morphology of woody phytoliths and their preservation in soils, we described the phytolith morphology of 60 common broadleaved woody plants in the mid-subtropical zone of China, based initially on anatomical origin, and then on shape and finally on texture. We also for the first time established an index (R value) to explore the preservation of broadleaved phytoliths in soil in this region. Results We divided the phytoliths of broadleaved woody plants into 6 major types and 36 sub-types. The 6 major types are: epidermal phytoliths, silicified stomata, tracheid, favose phytoliths, hair, and others. We found some degree of correspondence between different phytolith types and the parent plants. Fagaceae, Lauraceae, Magnoliaceae, Rosaceae, Anacardiaceae and Euphorbiaceae could be clearly distinguished from other families based on phytoliths. Only eight types of broadleaved phytoliths were present in the soils. Elongate attenuate, elongate tenuous psilate, and blocky regulate were better preserved in soils than the other types (elongate attenuate entire, tabular sinuate, hair, sclereid, and favose phytoliths). Conclusion Our results provide an important basis for the further application of phytoliths in paleovegetation reconstruction.