中文摘要：

选取华南沿海丘陵山地3个南亚热带不同地点及海拔的钻孔岩芯进行了微炭屑统计分析,结合孢粉分析结果,揭示全新世以来的植被变化与火灾历史,并探讨火灾事件与季风变化和人类活动的关系。结果表明：从8 000―3 500 cal.a B.P.,3个钻孔的微炭屑浓度均极低,证明该时段森林火灾频率很低,同时高木本含量的孢粉分析结果反映了亚热带阔叶林的繁盛,并指示全新世大暖期湿润和降雨丰沛的气候特征。加上早中全新世南方人口稀少,无＂刀耕火种＂等大面积农业活动。从3 500 cal.a B.P.开始,多个钻孔显示出微炭屑含量的迅速增加并持续高值,这与华南地区夏季风减弱导致降雨减少、气候变干,以及华南地区人类历史从新石器晚期进入商周时代的转折期密切相关。同时,孢粉指示的阔叶类木本植物含量显著减少,表明火灾对森林破坏逐渐严重。2 000 cal.a B.P.以后,人口出现第一次增长高峰,考古出土的器物证明牛耕和铁器农具开始广泛使用,农业快速发展。这一时期低海拔的GY1和中海拔的LTY钻孔微碳屑含量维持高值,禾本科以及芒萁属等次生植物孢粉含量快速增加。这反映了秦或南越国以后在华南地区较低海拔山地和平原农业活动得到迅速发展。此外,位于海拔1 600 m以上的钻孔GT-2的微碳屑记录显示：高海拔山区在800 cal.a B.P.以后才开始出现频繁的森林火灾,反映人类农业活动和人口增加扩张到高海拔山区。

英文摘要：

Three cores at different elevations were collected from different geographical locations in the mountainous regions of the South China. Micro-charcoal and pollen analyses were conducted to examine regional Holocene fire history and discuss its possible relationship with both Asian monsoon variability and anthropogenic activities. Results showed extremely low micro-charcoal concentrations at the three cores at the period between 8.0 and 3.5 ka B.P., revealing low fire frequency. Meanwhile, high proportions of arboreal pollen demonstrated expansion of subtropical evergreen broadleaf forest. This phase is consistent with the Holocene moisture optimum and abundant precipitation. Furthermore, low population in the early-mid Holocene and no evidence of slash-and-burn cultivation during the Neolithic confirm the charcoal result. After 3.5 ka B.P., the abrupt increase in charcoal concentrations of the cores from lower elevation sites was closely related with a general drying trend towards the late Holocene, which might result from EASM weakening and decreased rainfall. This timing coincided with the Shang-Zhou Bronze period, reflecting also the impact of human activity. The notable decrease of arboreal pollen demonstrates severe damage of forest by fires. After 2.0 ka B.P., the high concentrations of micro-charcoal recorded in the cores of GY1 and LTY, as well as the rapid growth of Poaceae, Dicranopteris and Pinus, demonstrate agriculture development in low-altitude plains and hills, and this period is synchronous with the first population booming and spread of cow plough and iron farm implements. Micro-charcoal and pollen records of core GT-2 at higher elevation（〉1 600 m） show a high fire frequency after 0.8 ka B.P., and this period saw severe disturbance of broadleaved forest by the expansion of anthropogenic activities and agriculture development to mountainous regions.