地理科学 ›› 2013, Vol. 33 ›› Issue (10): 1259-1267.doi: 10.13249/j.cnki.sgs.2013.010.1259

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惠州黄洞水库沉积速率及孢粉的环境指示意义

陈碧珊1(), 郑卓1(), 黄康有1, 郑艳伟2, 许清海3, 张晴华1, 黄旭蕾1   

  1. 1. 中山大学地球科学系,广东 广州 510275
    2. 广州地理研究所,广东 广州 510070
    3. 河北师范大学资源与环境科学学院,河北 石家庄 050016
  • 收稿日期:2013-01-02 修回日期:2013-04-21 出版日期:2013-10-20 发布日期:2013-10-20
  • 作者简介:

    作者简介:陈碧珊(1982-),女,广东汕头人,博士研究生,主要从事第四纪孢粉、环境演变与生物响应研究。E-mail:chenbishan2008@126.com

  • 基金资助:
    国家自然科学基金(41230101;40730103)及中山大学中央高校基本科研业务费专项资金(10lgzd08)资助

Sedimentation Rate and Environmental Reconstruction Based on Grain-size and Pollen-spores Analysis from Huangdong Reservior, Huizhou

Bi-shan CHEN1(), Zhuo ZHENG1(), Kang-you HUANG1, Yan-wei ZHENG2, Qing-hai XU3, Qing-hua ZHANG1, Xu-lei HUANG1   

  1. 1.Department of Earth Science, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
    2.Guangzhou Institute of Geography, Guangzhou, Guangdong 510070, China
    3.College of Resources and Environment of Hebei Normal University,Shijiazhuang, Hebei 050016, China
  • Received:2013-01-02 Revised:2013-04-21 Online:2013-10-20 Published:2013-10-20

摘要:

对惠州黄洞水库沉积钻孔(HD)进行了210Pb和137Cs测试,结合岩性、粒度分析和建库历史资料为佐证,以137Cs为主确定了研究区沉积物年代序列和沉积速率,同时对钻孔沉积物进行了孢粉和炭屑指标的实验分析。粒度分析结果表明,建库前沉积速率较快(约为1.5 cm/a),建库后(1960年以来)沉积速率降低(约为1.0 cm/a)。钻孔孢粉组合和炭屑记录揭示出与人类活动有关的孢粉种类为禾本科(Gramineae)花粉、芒箕(Dicranopteris dichotoma)、松属(Pinus)花粉等,孢粉绝对浓度和乔木与非乔木花粉比值(AP/NAP)是指示森林覆盖度的重要指标。同时出现乔木花粉减少、孢粉总浓度下降及禾本科相对含量上升,表明了裸地增加和水土流失严重,为人类砍伐和焚烧频率最高的时期。显著的大面积山火事件可以根据沉积物炭屑浓度与孢粉浓度比值(C/P)的峰值来判断。孢粉和炭屑记录揭示流域内建库前、大跃进–文革期、改革开放中后期3个时期不同的植被生态条件,反映了不同阶段人类活动方式和强度的变化,与历史文献记载的1958年大炼钢铁、1963年百年一遇大旱和1986年造林绿化工程等主要事件对比显示出一致的变化。

关键词: 孢粉, 炭屑, 沉积速率, 人类活动, 黄洞水库

Abstract:

A sediment core was collected from the northeast of the Huangdong Reservoir in Huizhou, Guangdong province. Environmental 137Cs and 210Pb dating techniques (mainly with 137Cs) were applied to determine the chronology and modern sedimentation rates of the Huangdong Reservoir, by combining with the sediment lithology, grain size and the historical data on the construction of the reservoir. Meanwhile, a lab analysis was conducted on the pollen analysis and charcoal to explore the significances to the environment and reveal the past environmental changes, vegetation and ecological conditions of the reservoir. The grain size analysis result showed that the sedimentation rate was faster (approximately 1.5 cm/a) before the construction of the reservoir; and it decreased (approximately 1.0 cm/a) after the construction of the reservoir(since 1960s). The records on pollen assemblages and charcoal revealed that the pollens of herbs (such as Gramineae), spores of fern (such as Dicranopteris dichotoma) and Pinus were relative with the human activities. The concentration of pollen and AP/NAP ratios (arboreal pollen/non-arboreal pollen) were the important indicators to reveal the changes of the forest coverage. Human activities’ influence on vegetation was manifested in the decrease in pollens of tree, the drop in the total concentration of pollens, the increase in pollens of herbs. And it showed that the bare land or water and soil loss increased significantly if humans cut down and burned frequently. Significant large areas of forest fire events could be according to peak value of charcoal concentration as well as the C/P value (ratio of charcoal and pollen). This study revealed the vegetation ecological information of three different stages in the basin, i.e. the period before the construction of the reservoir, the period of Great Leap Forward and the Cultural Revolution, and the subsequent period of reform and opening up. Such information uncovered the changes of human activities in modes and intensities in different historical periods. The results of pollen assemblages and charcoal index analysis were consistent with the main events of the great Steel-Making movement in 1958, the hundred-year drought in 1963, and the afforestation project in 1986 which were recorded in the historical documents.

Key words: pollen, charcoal, sedimentation rate, human activity, Huangdong Reservoir

中图分类号: 

  • P343.3