Research On The Modle Between Pbytoliths And Climate Factors

Silicon was absorbed by plants from the soil and then transformed into phytolith, andfinally returned to the soil through the plant residues, so phytolith has been widely used torecover and reconstruct paleoenvironment and paleoclimate. However, the correspondingrelationship between plant communities and soil phytolith assemblages has not been clearlydefined though the scholars had done some research. It had been more important to definiterelationship between plant communities and soil phytolith assemblages after high resolutionoffered, as it is the key to recover and reconstruct paleoenvironment and paleoclimate exactly.The aim of the present work is to find the corresponding relationship between plantcommunities and soil phytolith assemblages using Detrended Correspondence Analysis（DCA）, and to obtain correction coefficientt （CC）, which can help to revise the percent ofphytoliths from the soil. Then phytoliths assemblages whose corresponding relationship isnice will be selected to build a model between phytoliths and climatic factors by the stepwiseregression.Both the soils and plants were gathered from48selected sites from Changbai Moutainby the plum flower sample method. An inventory of phytolith types is provided andtype-frequencies are assessed. And the result shows that phytoliths is abundant in only34sites, and elongate, crenate, rondels and point-type phytoliths were abundant in all the points,indicating that the climate of this area is cold.Owing to the gradient length of all the four axis is less than3, DCA analysis is not fit tothese data, PCA was used to find the taxonomic diagnostic potential of phytoliths. Resultsshow that the temperature is the primary factor, and the second one is the humidity. It alsoreveals that there is a corresponding relationship, to a certain extent, between plantcommunities and surface soils phytolith assemblages.In order to uncover the corresponding relationship between the plant community andsurface soils phytolith assemblages, CR, which means the radio of plant community phytolithcontent and soils phytolith content, was used to revise the frequency of soils phytolith. Itclassified5surface soil phytolith conservation level-worst, worse, normal, better, best. Theresult of CR shows that phytolith assemblages preserved well, which means phytoliths havethe characteristic of autochthonous deposit even though that in a bigger slope. While the CRshows bigger difference in the wetlands. Overall, all the phytolith types, except the silicifiedstomata and the papilla, preserve well.Abnormal value was removed according to result of ANVOA, and then CC, which is the average of CR in the same phytolith type from different sites, was obtained, Followed byrevising the frequency of Surface soil phytoliths.34climate databases, collected from1961to1990, were selected in order to build the model by stepwise regression. This modelreconstructed10ka Holocene climatic changes. Our phytolith-based reconstructions fromHuanan have produced MAT and MAP values comparable with those derived from pollen andlocally based environmental inferences at the glacial-interglacial timescale (GRIP and GISP2δ¹⁸O). A series of cold and/or dry events were indicated by the reconstructed MAT and MAPas documented in peatland sequence of the last glacial period, which can be temporallycorrelated with the North Atlantic Heinrich events, suggesting that this model has thereference value.