柴达木盆地东部表土花粉分析  

A study on topsoil pollens in the east of Qaidam Basin

作　　者：陈辉[1] 吕新苗[1] 李双成[2] 

机构地区：[1]中国科学院地理科学与资源研究所 [2]北京大学环境学院,北京100871

出　　处：《地理研究》2004年第2期201-210,共10页Geographical Research

基　　金：国家重点基础研究发展规划项目:青藏高原形成演化及其环境;资源效应 (G19980 40 816)和青藏铁路的生态环境效应 (90 2 0 2 0 12 )资助

摘　　要：柴达木盆地东部荒漠区 8个样地、 2 3个样点的表土花粉分析较好地揭示了荒漠区花粉组合的特点及其与植被、环境的关系。研究发现 ,荒漠区表土花粉以藜科 (Chenopodiaceae)和蒿属 (Artemisia)为主 ,并以前者占优势地位 ,麻黄属 (Ephedra)亦较常见 ,禾本科(Gramineae)、菊科 (Compositae)植物在群落中也占有一定的比例。花粉百分比含量DCA排序与相关分析发现 ,荒漠区不同植物群落下表土花粉组合特征各不相同 ,而且与相应的植物群落及其所代表的环境特征相一致。荒漠区表土花粉蒿 /藜 (Artemisia/Chenopodiaceae)比对干旱程度具有指示作用 ,比值越小 ,越干旱。The features of pollen assemblages are dealt with in this paper using the methods of DCA and correlation analysis. Altogether 23 samples taken from topsoils at 8 sites in the east of Qaidam Basin are studied. In this study area, pollen taxa are mainly shrubs and herbs, whose total percentage is 92.77%～100%. Pteridophyta pollen is found in 5 samples, but the percentage is quite low, only less than 0.38%. This pollen assemblage clearly shows the characteristics of obvious desert and steppe desert area without trees. In the pollens of shrubs and herbs, Artemisia and Chenopodiaceae dominate in desert area, being respectively about 40% and 70% in general and 66.38% and 74.54% at maximum. Comparatively, Ephedra is also commonly seen, whose percentage is usually less than 5%, but in 6 samples the percentage is more than 10% and 49.27% at maximum. Gramineae and Compositae also occupy a certain percentage, the maximum may reach 10.6% and 6.82%. Results of DCA and correlation analysis appear that the features of topsoil pollens in different vegetations are not the same. Different assemblages of pollens can be distinguished and are in accordance with corresponding vegetations and environments. According to the aridity, the vegetation communities are divided into four groups: severe drought group, moderate drought group, slight drought group and slight-drought-and-slight-wetness group and it is found that A/C (Artemisia/ Chenopodiaceae) in the desert can indicate the aridity. A/C value is less 0.2 in the severe drought group, 0.2～0.5 in the moderate drought group, 1.63 in the slight drought group and 5.72 in the slight-drought-and-slight-wetness group with aridities being 8.96, 3.00, 2.98 and 2.82 respectively.

关 键 词：柴达木盆地东部 表土花粉 DCA排序 相关分析 蒿/藜比 

分 类 号：P531[天文地球—古生物学与地层学] Q944.42[天文地球—地质学]