植物燃烧微炭屑与植硅体的比值研究

STUDY ON THE RATIO OF MICROCHARCOAL PARTICLES TO PHYTOLITHS DERIVED FROM PLANT COMBUSTION

炭屑与植硅体分析广泛应用于古环境重建研究,现代植物燃烧微炭屑与植硅体比值研究有利于认识土壤及沉积物微炭屑与植硅体的丰度与火灾和燃烧活动之间的关系。本研究利用现代草本及木本植物叶片进行开放燃烧模拟实验,分析了不同植物燃烧微炭屑的形态特征及微炭屑与植硅体数量比(Ch/ph)的差异。结果表明,植物燃烧后会残留下植硅体和微炭屑,草本与木本植物微炭屑形态特征具有明显差异,微炭屑与植硅体(Ch/ph)比值较大,Ch/ph值木本植物(26.07-31.61)大于草本植物(1.62-15.20)。微炭屑的形态及长宽比(L/W)、Ch/ph值含有丰富的火灾发生及燃烧的植被类型信息,尤其Ch/ph可能是古火灾及古植被重建研究的潜在替代指标。

Microcharcoal and phytolith analyses are widely used in the paleoenvironment reconstruction.The study on the ratio of microcarbon particle to phytolith derived from the plant combustion is useful to understand the relationships between their abundances and paleo-wild fire and ancient human activities.However,the difference between the ratios of microcharcoal particles to phytoliths and their source plant species burnt is not well understood.The combustion simulation experiments on modern herbs and woody plant leaves were carried out to analyze the microcharcoal morphological characteristics and the difference among the ratios of microcharcoal to phytolith numbers(Ch/ph)derived from combustion of different plants.It shows that plant burning produces abundant phytolith and microcharcoal particles,there are apparent morphological differences between grass and woody plant microcharcoal.The data show the ratios of microcharcoal particles to phytoliths in plant ashes are rather high,and the Ch/ph values of woody plant(26.07-31.61)are greater than herbaceous plant(1.62-15.20).The morphological characteristics and the ratio of length to width of microcharcoal,and the Ch/ph reflect the fire occurrence and the burning vegetation type.In particular,the Ch/ph may be the potential proxy used for reconstruction of paleo-fire and paleo-vegetation。