徐景先   David K. Ferguson   李承森   王宇飞

摘 要  云南吕合晚中新世孢粉植物群含48个孢粉类型，归属35个科，其中被子植物占72.9%，裸子植物占12.5%，蕨类植物占14.6%。根据各植物类群孢粉含量在整个剖面上的变化情况，将吕合中新世地层剖面划分为三个花粉带，花粉带I：以常绿栎类，桤木属和榛属植物为主，松属植物少；花粉带II：常绿栎类和榛属植物变少，松属植物增多；花粉带III：阔叶植物变少，针叶树增多。运用共存分析方法，定量恢复了吕合地区晚中新世七个古气候参数值：年均温13.3—20.9°C ，最热月均温22.5—27.5°C，最冷月均温2.5—12.6°C，年较差12.1—24.8°C，平均年降雨量803.6—1254.7mm，最大月降雨量179.4—249.6mm，最小月降雨量10.2—18.5mm。与吕合现在气候数据对比表明吕合地区在晚中新世时期属于更温暖，而且降雨量大的亚热带气候。

关键词：晚中新世 植被 气候 孢粉学 吕合 云南

Late Miocene Vegetation and Climate of the Lühe Region in Yunnan, Southwestern China
Jing-Xian Xu  David K. Ferguson 
Cheng-Sen Li  Yu-Fei Wang

Abstract  The Lühe coalmine (25°10′N, 101°22′E) is located in Chuxiong County of Yunnan Province, southwestern China. Its Late Miocene palynoflora consists of 48 sporomorphs that are assigned to 35 natural families, including angiosperms (72.9%), gymnosperms (12.5%) and ferns (14.6%). Three pollen zones are recognized: The assemblages of Zone I are dominated by evergreen oaks, alder and hazel, while pine is present in comparatively low percentages. Zone II is characterized by smaller percentages of oak and hazel and more pine. In Zone III there is an expansion in the number of conifers at the expense of the broad-leaved trees and shrubs.Following the Coexistence Approach, seven palaeoclimatic parameters (Late Miocene) of Lühe are estimated. The mean annual temperature ranged from 13.3 to 20.9°C, the mean temperature of the warmest month from 22.5 to 27.5°C, the mean temperature of the coldest month from 2.5 to 12.6°C, the difference in temperatures of coldest and warmest month from 12.1 to 24.8°C, the mean annual precipitation from 803.6 to 1254.7mm, the mean maximum monthly precipitation from 179.4 to 249.6mm and the mean minimum monthly precipitation from 10.2 to 18.5mm. Comparison with the modern meteorological records indicates that the Lühe area had a warmer subtropical climate with more precipitation during Late Miocene; these data could indicate that extensive uplift of the western Yunnan Plateau had not yet occurred.

Key words  Late Miocene, vegetation, climate, palynology, Lühe, Yunnan

Review of Palaeobotany and Palynology，148 (2008) 36–59