Luochuan Area The Last Interglacial Paleo-vegetation Evolution And Reduction Research

Last interglacial age is the most recent one interglacial.It has some similarity to the character of contemporary climate.So the last interglacial period is the focud period of the climate-change research.The spore-pollen in loess is the relic of biosphere in the Quaternary period.And it represents the vegetation when their stratum formed.The vegetation is high sensitive with the climate.The change of vegetation will show the character of climate fluctuation.As a result,applying spore-pollen record to reconstruct the paleo-vegetation evolution has been an important problem in the global change study.Luochuan guzui profile was selected as the study object.We sampled intensively by 2cm interval and analysis the spore-pollen record in the loess.And then the chart of spore-pollen percentage and mass concentration has been established for reconstruct the paleo-vegetation of last interglacial age in Luochan area.And we select a part of records for trying reconstruct paleo-vegetation quantitatively by using biomezation method.Then we discussed the result and the error.The study indicated three point:1.In last interglacial period,grassland- forest steppe- grassland vegetation types developed in Luochuan area.Assemble zoneⅡc,Ⅲb,andⅣinclude the mass concentration peak.And the peak in assemble zoneⅢb is weak.2.There are plenty of pollen discovered in S1 paleosol in Luochuan area,including some of woody types.It shows the good climate condition existed in last interglacial. There is a cycle of vegetation change in the interglacial period.The forest steppe can lived in some period when the condition of water and heat were appropriate.3.The conclusion from the biomezation method is different from qualitative analysis.There are a trend that the vegetation changed to dry type.