岱海盆地99A孔11.01m以上地层较高分辨率的孢粉分析揭示了该区以来的植被演替和气候变化。早全新世时期，岱海盆地受冬季风影响强烈，气候波动以冷湿、暖干为主，12 000～11 000 cal a BP为以白桦林为主的森林草原植被，气候寒凉湿润；11 000～7 900 cal a BP白桦林退缩，气候温干；中全新世时，主要受控于夏季风影响下，气候波动以冷干、暖湿为主，7 900～4 450 cal a BP是岱海盆地森林植被发育最好的时期，气候温暖湿润，4 450～2 900 cal a BP森林开始退缩，气候温干；2 900～0 cal a BP在气候变凉干和人类活动的影响下，森林植被几近消失。

Daihai Lake lies in the transitional area from semi-humid to semi-arid region, and also in the north margin of the East Asia monsoon. The analysis of 65 pollen samples from the surface sediment of Daihai Lake and alluvium of its in flow rivers revealed the characteristics of pollen distribution and different transport vectors. Most pollen grains in Daihai Lake come from its inflow rivers, although rain-out and wind are also important. Activities of insects, birds and humans may also carry pollen into the lake. The pollen assemblages are consistent with the regional vegetation in general. The variance of pollen assemblages in different parts of the lake reflects changes of local vegetation near the lakeshore. Pollen concentrations in the lake sediment surface are lower than that in fresh alluvium in its inflow rivers, and the highest percentages and concentrations of major pollen types mainly appear in the margin part of the lake. DCA demonstrated that there are more similarities between lake sediments and the inflow rivers than there are differences.

建立花粉与现代植被的关系是利用地层沉积物中的花粉记录恢复古植被、古气候研究的基础工作之一。中国北方草原区39个表土花粉研究表明，蒿属、藜科是草原区花粉组合的主要成分，以禾本科为建群种的草原群落花粉组合以蒿属花粉为主，禾本科花粉多低于10%。禾本科花粉的低代表性可能与其分蘖繁殖、花粉产量低有关。草原区表土花粉浓度与植被盖度相关不明显。典型草原与荒漠草原花粉组合存在着明显的区别，典型草原区藜科花粉百分比一般低于25%，荒漠草原区一般高于25%。DCA分析表明，草原区针叶树、莎草科、石竹科花粉代表较湿润的环境，蒿、藜科、锦鸡儿、柽柳、白刺花粉代表较干燥的环境，阔叶树、禾本科、菊科、毛茛科、蓼科、豆科、唇形科(百里香)、虎榛子 + 榛、蔷薇科花粉代表的环境介于前两组之间。DCA分析用于草原区花粉组合研究具有较好的环境指示意义。

滦河流域及周边地区空气中的花粉组合基本上反映了当地的植被面貌，与植物的花期相对应，乔木植物的花期多在春季，草本植物的花期多在夏秋季，该地冬季基本上无植物开花，冬季空气中的花粉应是当年或多年春、夏、秋季散落在地上又被风吹到空气中的表土花粉和一些外来花粉;表土花粉随海拔高程的降低依次出现山地草甸、针阔混交林或以针叶树为主的针阔混交林、山地灌草丛、滨海平原草甸和滨海草甸或滨海盐生草甸的等5个花粉组合带，分别为蒿(Artemisia)–唐松草(Thalictrum)–松(Pinus)–桦(Betula)孢粉组合带、松–桦–栎(Quercus)–蒿孢粉组合带、藜科(Chenopodiaceae)–蒿–禾本科(Gramineae)–中华卷柏(Selaginellasinensis)孢粉组合带、藜科–蒿–菊科(Com-positae)–香蒲(Typha)孢粉组合带和藜科–蒿–莎草科(Cyperaceae)–禾本科孢粉组合带；由于花粉在河水中是以悬移质颗粒被搬运，因此在不同时期沉积物花粉组合存在着一定的差异，其中洪水期间河水对孢粉的分选作用最为明显。

Qinghai-Tibetan Plateau is one of the most sensitive areas to climate change of the earth, owing to its unique topographic features and ecosystem. Soil pollen analysis is an important component of palaeo- ecological research, while pollen preservation and the relationship between pollen and vegetation can influence the correct interpretation of fossil pollen spectra. In this paper, 36 pollen samples, which come from four meadows and two forest soil pollen profiles, have been analyzed to determine relationships between pollen and vegetation and pollen preservation on the northeastern Qinghai-Tibetan Plateau. The relationship between pollen and vegetation shows that the surface pollen assemblages can represent regional vegetation characteristics moderately, while Betula and Populus pollen is absent in the soil surface for Betula and Populus mixed forest. Artemisia, Chenopodiaceae, Ephedra, Pinus, Hippophae etc. are over-represented pollen taxa, Leguminosae, Ranunculaceae, Rosaceae, Gramineae etc. are under-represented pollen taxa. The study of pollen preservation indicates that pollen concentrations decrease with the increase of soil depths, more pollen taxa are present in surface soils than in deep levels, and more than 75% pollen grains will be lost from the surface soils to deep levels. Pollen sorting preservation function should be noticed. Artemisia and Chenopodiaceae can be preserved well and have higher pollen percentages in deeper levels. Cyperaceae and Populus are preserved worse, Populus pollen is absent and Cyperaceae has higher pollen percentages in the surface soil than in the deep levels. The high soil pH values are the most destructive factors for pollen preservation on the northeastern Qinghai-Tibetan Plateau. Pollen concentrations decrease sharply when the soil pH values are over 7.6. Downward leaching of pollen is unimportant in this study.