DH99a sediment core recovered at the center of Daihai Lake in north-central China was analyzed at 4-cm intervals for pollen assemblage and concentration. The pollen record spanning the last ca 10000 yr revealed a detailed history of vegetation and climate changes over the Daihai Lake region during the Holocene. From ca 10250 to 7900 cal yr BP, arid herbs and shrubs dominated the lake basin in company with patches of mixed pine and broadleaved forests, indicating a mild and dry climatic condition. Over this period, the woody plants displayed an increasing trend, which may suggest a gradual increase in warmth and humidity. The period between ca 7900 and 4450 cal yr BP exhibits large-scale covers of mixed coniferous and broadleaved forests, marking a warm and humid climate. Changes in the composition of the forests indicate that both temperature and precipitation displayed obvious fluctuations during this period, i.e., cool and humid ca 7900-7250 cal yr BP, warm and slightly humid ca 7250-6050 cal yr BP, warm and humid between ca 6050 and 5100 cal yr BP, mild and slightly humid ca 5100-4800 cal yr BP, and mild and humid ca 4800-4450 cal yr BP. The period can be viewed as the Holocene optimum (characterized by a warm and moist climate) of north-central China, with the maximum (dominated both by warmest temperatures and by richest precipitations) occurring from ca 6050 to 5100 cal yr BP. During the period of ca 4450-2900 cal yr BP, the woody plants declined, and the climate generally became cooler and drier than the preceding period. This period is characterized by a cold, dry episode from ca 4450 to 3950 cal yr BP, a warm, slightly humid interval between ca 3950 and 3500 cal yr BP and a mild, slightly dry episode from ca 3500 to 2900 cal yr BP, and appears to be a transition from warm and humid to cold and dry climatic conditions. Since ca 2900 cal yr ago, the forests disappeared and the vegetation density decreased, reflecting a cool and dry climate. However, a relative recovery of the woody plants occurring between ca 1700 and 1350 cal yr BP may denote an increase both in temperature and in precipitation. Fluctuations in the climatic condition of the Daihai Lake region were not only related to changes in the seasonal distribution of solar insolation and in the axis and intensity of the ocean current in the western North Pacific but were also closely linked to variations in the position and strength of polar high-pressure systems and in the pattern and intensity of the Westerly winds.

从考古孢粉学角度，根据赤峰七锅山剖面孢粉分析，结合赤峰地区古文化遗址的考古资料，探讨了赤峰地区8000 a B. P. 以来的先人生活环境，以及人类活动和自然环境演变的过程之间的相互关系。结果表明：8400～6200 a B. P. 为温暖湿润的草原气候，先人既狩猎捕鱼，也种植作物和放牧；6200～4000 a B. P. ，随着森林的破坏，环境逐渐恶劣，农业水平下降；4000～2500 a B. P. 植被以草原为主，气候温干，先人以旱作农业为主；2500 a B. P. 至现在，植被为典型的蒿草草原，气候温和偏干，农业和畜牧业相对发展，人类活动加剧。

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.

利用燕山地区几个主要植物的花粉-气候响应面模型，定量恢复了燕山南部5000a B. P.来的气候变化。5000a B. P.以来，燕山南部的气候曾发生过两次明显的降温事件，一次发生在4500～3600a B. P.，7月份平均气温比今低2.0℃左右；一次发生在2750～1750a B. P.，7月份平均气温比今低3.7℃左右；2000a B. P.以来年均降水量一直呈下降趋势，年均降水量比2000a B. P.前减少50～100mm。孢粉分析表明，燕山南部人工栽培板栗的历史可以追索到1600a B. P.，种植水稻的历史可以追索到700a B. P.。

取自青藏高原东北部不同植被类型的6个土壤剖面花粉与植被关系研究表明，表土花粉较好地代表当地植被的组成，区域外花粉百分比低于30%，但桦、杨花粉在植被中的代表性较差；土壤剖面典型花粉类型的埋藏特征表明：在土壤表层8cm以下，花粉总浓度迅速降低。氧化作用对花粉的破坏性最大，花粉浓度随土壤的pH值升高呈指数形式递减，pH值7.6以上，花粉浓度迅速降低，花粉在土壤中的运移作用不明显。