东北地区泥炭表层沉积中植硅体分布特征

Phytolith Distribution in the Surface Peat Deposit of Northeast China

表土沉积物中的植硅体分析是了解第四纪沉积物中植硅体组成的重要途径,也是重建第四纪古环境的基础。对东北地区跨越3个气候带、6个地区的41处泥炭地表土中的植硅体进行提取,鉴定出东北泥炭表土中主要发育哑铃型、扇型、鞍型、方型、长方型、梯型、尖型、帽型、齿型、棒型和其它等11种植硅体类型。分析显示,它们的分布与纬度、地形和温热条件具有明显关系,即哑铃型、鞍型、扇型、方型、长方型和梯型植硅体随纬度和海拔较高而含量较小,其余类型反之;较高温度条件对应扇型、哑铃型植硅体含量较高,较高湿度对应扇型植硅体含量较高。

Phytolith analysis in the surface soils is not only an important approach of studying phyto lith assemblages in the Quaternary sediments, but also a basis of Quaternary environment reconstruc- tion. Phytolith from 41 sites of 6 areas and 3 climate belts of Northeast China were extracted and classified into 11 types： dumbbell-shaped, saddle-shaped, fan-shaped, square-shaped, rectangular-shaped, ladder-shaped, cap-shaped, point-shaped, crenate-shaped, elongate-shaped, and other-shapes. Analysis showed that, there were relations between the phytolith distribution and the latitude, the altitude, temperature and heat. with the increase of the latitude and altitude, the contents of dumbbell-shaped, saddle-shaped, fan-shaped, square-shaped, rectangular-shaped and ladder-shaped phytolith decrease, or vice versa; a warmer temperature is always corresponding with higher contents of fan-shaped and dumbbell-shaped phytolith, the more humid, the higher content of fan-shaped phytolith.