Records Of Surface Wetness From Hani Mire In Changbai Mountains

Peatlands are very important archive in past global climate changes research. Study on the environmental changes of peatlands can not only reveal the law of peatlands themselves, but also reconstruct past climate history. So, it plays a role in regional climate changes.Hani mire which is situated on west of Changbaishan mountains is the one of the biggest mires in northeast of China. It lies in sensitive area of global change with less human disturbance, constantly deposition, and well preserved, so Hani is ideal region for environmental changes study. According to multi-year mean effective precipitation, Hani mire is very sensitive to climate changes, so the peat core from Hani mire recorded sensitive information about past climate changes in this region.In this paper, plant macrofossil, humification and loss on ignition analyses have been used and cross-checked to reconstruct past mire surface wetness from Hani mire.Quadrat and Leaf Count Macrofossil Analysis(QLCMA) is employed to obtain percentage of each category in every one peat layer at 1cm interval,and plant succession of the whole profile(0cm-50cm), and percentage of each component. The result shows that sphagnum is the main component of the whole profile. Detrended correspondence analysis was used to transform the raw floral data into indices of mire surface wetness. The sorting of species on DCA axis1 is according to the water table. This suggests that plant succession on Hani mire is the result of water table changes, but not interspecific competition.The absorbance of NaOH extraction from peat is used to characterize the humification according to ACCROTELM. High humification represents low mire surface wetness, whereas low humification shows that mire surface is relatively wet. So, we obtain the wetness changes of Hani mire according to humification proxy. The results of correlation analysis show that there is significant correlation between humification proxy and plant macrofossil DCA axis1 scores, therefore humification and plant macrofossil are excellent proxy for mire surface wetness.The determination of mire surface wetness also refers the results obtained from loss on ignition proxy. According to comprehensive analysis of plant macrofossil, humification and loss on ignition proxy, 5 phases of Hani mire surface wetness changes are inferred. The drivers of mire surface wetness changes are discussed, and that temperature is thought maybe the one that induces the mire surface wetness changes.