中国东部淤泥质海岸盐沼植被藜科花粉数量研究

On the quantity of Chenopodiaceae pollen in salt marsh vegetation of muddy coast in East China

选取中国东部江苏盐城和辽宁盘锦两地淤泥质海岸盐沼植被带,经植被调查和表土孢粉分析,讨论藜科(Chenopodiaceae)花粉数量与沿岸潮上带密布的碱蓬属(Suaeda.sp)植物群落的数量关系,论证藜科花粉含量与淤泥质岸线位置的关系。研究认为,当沿海古淤泥质地层中的孢粉组合,藜科花粉超过30%,可以判定为古海岸线潮上带。如果藜科花粉为20%~30%,多见禾本科(Poaceae/Gramineae)、莎草科(Cyperaceae)的花粉,表明为海滨盐沼植被景观,古海岸线潮上带离之不远。第四纪古岸线变化研究,验证了藜科花粉数量可以作为判定淤泥质古岸线的代用指标。

Taking the salt marsh vegetation zones in two muddy coasts in Yancheng Nature Reserve, Jiangsu province and Panjin Red Beach, Liaoning province, eastern China as the study areas, we investigated vegetation and analyzed surface pollen samples in the vegetation zones. Then, we discussed the relationship between percentages of Chenopodiaceae pollen and plant community of Suaeda. sp widespreading on supratidal zone, and the relationship between percentages of Chenopodiaceae pollen and coastline positions. The result shows that the sampling site could be near an ancient coastline(supratidal zone) when Chenopodiaceae pollen percentages in the pollen assemblages of coastal muddy ancient strata exceed 30%. When Chenopodiaceae pollen percentages are about 20%- 30% in pollen of Poaceae(or Gramineae),Cypeaceae and Artemisia are common in the pollen assemblages, it could be determined that the landscape around the sampling site was salt marsh vegetation and the ancient coastline was not far away from the sampling site. Some case studies reconstructing the ancient coastline changes during the Quaternary proved that reliability and applicability of Chenopodiaceae pollen can be taken as a proxy for studying ancient coastline in muddy coast. This study puts forward a new conception and method for ancient sea level research with pollen in China.