氧化环境对油松花粉保存影响实验研究

A Laboratorial Study of the Effect of Oxygenation Environment on the Preservation of Pinus tabulaeformis Pollen

花粉保存能力差异是影响花粉谱准确性的重要因素之一,采用KMnO4溶液和HNO3溶液作为氧化剂,模拟自然环境氧化条件对油松花粉保存影响情况。结果表明:同一KMnO4溶液浓度条件下,随时间延长油松花粉完好率呈下降趋势;浸泡相同时间,随KMnO4溶液浓度增大油松花粉完好率亦明显下降.经68%HNO3溶液浸泡18 h后,残留的完好花粉外壁变薄,纹饰变模糊,24 h后花粉几乎完全被溶解.一般认为油松花粉保存能力较强,而经2%KMnO4溶液和68%HNO3溶液处理后,发现在短时间内就足以使油松花粉大量破碎或溶解,表明氧化环境对油松花粉保存影响强烈.氧化环境对油松花粉腐蚀作用强于碱性环境.

Pollen is one of the important indexes in reconstructing paleoclimate and paleoenvironment. The difference of preservation abilities of different pollen taxa is very important to pollen spectra veracity. It is generally believed that oxygenation action is one of the strongest chemical actions to pollen preservation, so the longer pollen exposed in surface soil, the greater possibility of pollen being oxygenated. In order to validate the statement, the destructive effect of oxygenation environment on Pinus tabulaeformis pollen grains is investigated by simulating a natural situation in laboratory, using KMnO4 and HNO3 as an oxidant. The following viewpoints and conclusions are put forward： the Intactness ratio of Pinus tabulaeformis pollen grains marinated in the same liquor concentration shows a decreasing trend with time. It is true that along with the liquor becoming denser for the same reaction time the Intactness ratio decreases. The Intactness ratio is less than 1% while dipping in 2% KMnO41iquor for 1 hour; after dipped in 68% HNO3 for 18 hours, the remnant pollen exine became thin, ornament became faint and almost were all dissolved for 24 hours. It is very clear that the oxygenation environment has a serious influence on Pinus tabulaeformis pollen preservation. The influence of alkaleseence environment on Pinus tabulaeformis pollen is studied, revealing that alkalescence environment has a bit of effect on pollen eroding, but it can not destroy pollen grains obviously, so oxygenation environment has stronger destruction ability to Pinus tabulaeforrnis pollen than alkalescence environment. Pinus tabulaeformis pollen possesses strong preservation ability. However, more study of the erosion mechanism of other pollen taxa that have weak preservation ability is needed.