河南洛阳寺河南剖面中全新世以来的孢粉分析及环境变化

对河南洛阳寺河南剖面进行的高分辨率的孢粉分析表明，该地区中全新世以来的孢粉组合以草本植物占绝对优势。其中以蒿属（Artemisia）最为丰富，其次为禾本科（Gramineae）和藜科（Chinopodiaceae）。乔木花粉含量较少，以松属（Pinus）为主。根据孢粉组合的变化，将剖面划分为5个孢粉组合带。早期（7.235～7.380 aBP）气候较为寒冷干燥，缺少乔木花粉。随着全新世大暖期的到来，在Ⅱ孢粉带上乔木花粉大量出现，种类丰富。尤其5.625～6.120 aBP期间出现了很多喜暖树种，是中全新世以来气候最好的时期。在4.580～5.625 aBP期间，乔木花粉急剧减少，表明气候发生恶化。随着气候的逐渐好转，乔木花粉在Ⅳ孢粉带（3.090～4.580 aBP）上重新出现，但喜暖树种较少。3.090 aBP以后出现较多的禾本科花粉，可能和该地区人类活动的增强相关。

Paleoenvironment Changes Since Mid-Holocene Revealed by a Palynological Sequence from Sihenan Profile in Luoyang, Henan Province

The high resolution palynological records from Sihenan profile reveal that the non-arboreal pollen is the most important part of the pollen assemblage in Luoyang, Henan province within the last 7.000 aBP. The non-arboreal pollen mainly includes Artemisia, Gramineae and Chinopodiaceae. The arboreal pollen is sparse and mainly consists of Pinus. Five pollen assemblage zones are established through the stratigraphical changes of the pollen. 5.625--6.120 aBP interval is the best period in Holocene with a warm and wet climate. The profile includes two major cold peaks at 4.580--5.275 aBP and 6.120--6.375 aBP. The centennial-scale climate instability is obvious, which exists even in Holocene Optimum.