|
|||||
|
|
| 退化森林生态系统恢复过程的碳同位素示踪 | |
| 引用本文： | 沈承德,孙彦敏,易惟熙,彭少麟,李志安.退化森林生态系统恢复过程的碳同位素示踪[J].第四纪研究,2001,21(5):452-460. |
| 作者姓名： | 沈承德 孙彦敏 易惟熙 彭少麟 李志安 |
| 作者单位： | 1. 中国科学院广州地球化学研究所,广州,510640;中国科学院黄土与第四纪地质国家重点实验室,西安,710054 2. 中国科学院广州地球化学研究所,广州,510640 3. 中国科学院华南植物研究所,广州,510650 |
| 基金项目： | 国家自然科学基金 (批准号 :4 9973 0 0 9,3 98993 70 ,4 9894 1 70和 4 9872 0 93 )资助项目，中国科学院“九五”重大项 目 (批准号 :KZ95 1 A1 4 0 2 0 8 0 1 )，中国科学院“九五”重点项目 (批准号 :KZ95 2 J1 4 0 2 )，国家重点基础研究发展规划项目 (批准 |
| 摘 要： | 本文以鼎湖山自然保护区和鹤山丘陵综合试验站为对象,开展不同地区、不同森林类型的土壤有机碳(SOC)同位素示踪研究,探讨退化生态系统恢复过程中碳同位素的示踪作用.庆云寺和仓下剖面代表自然林,SOC的δ13C平均值分别为-24.63‰和-23.76‰;坑口和马占林剖面代表草坡上植树造林恢复的人工林,SOC的δ13C平均值分别为-21.22‰和-22.73‰;剖面底界SOC的14C表观年龄前者分别为8 750aB.P.和10 315aB.P.,后者分别为2 880aB.P.和4113aB.P..在SOC的14C表观年龄老的丘陵草坡上进行退化生态系统重建,有利于人工森林群落向地带性森林群落演替. |
| 关 键 词： | 退化森林生态系统 碳同位素示踪 |
| 收稿时间： | 2001-06-09 |
| 修稿时间： | 2001年6月9日 |
Carbon isotope tracers for the restoration of degenerated forest ecosystem |
|
| Institution: | National Laboratory of Western China′s Environmental Systems, Lanzhou University, Lanzhou730000 |
| Abstract: | Based on the negative correlation of the susceptibility with organic matter content and the degree of gleying, this study suggests that the reducing conditions contributed to the alteration of magnetic minerals from strong forms of oxidized iron to weak forms. Therefore, the magnetic susceptibility is basically an indicator of redox cycles. Well vegetated conditions generally dominated the later part of the last glacial maximum (15?000～10?000aB.P.)while poorly vegetated conditions during the early part of the last glacial maximum (21?000～ 15?000 aB.P.). The dark blue zone dated at 14?500 ～14?800aB.P. along the southern margin of the North American icesheet chronologically corresponds to a pollen and insect indicated climate amelioration in the Midwest of United States and to a period of C 4 plant domination in the central Great Plains. The transition may also be causally related to the drastic changes in ventilation of the deep North Atlantic water and to an extreme aridification in Africa around 15?000aB.P. The magnetic susceptibility signatures indicate about 1?000 year long cycles of eolian environmental changes during the last glacial maximum (21?000～ 10?000aB.P. ). The cycles seem to be well corroborated by about 1?000 year long cycles recorded in the South China Sea, Santa Barbara Basin, and Greenland. The initial perturbation of these～1?000 year long cycles might have started in the Tropical Pacific and then promptly transferred to the North Atlantic via the North American Icesheet ( i. e ., Laurentide Icesheet). That is, long term ENSO variations in the Tropical Pacific probably controlled North American Icesheet dynamics by influencing precipitation and perhaps temperature as well. Icesheet dynamics might, in turn, have influenced the North Atlantic sea surface temperature via iceberg discharges. Consequently, the North Atlantic might have controlled the high latitudes and Tropical Pacific and other tropical waters the low latitudes. The middle latitude lands might have been influenced by the Tropical Pacific related and/or the North Atlantic related events depending on their geographic and climatic positions. $$$$ |
| Keywords: | degenerated forest ecosystem carbon isotope tracer |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ | |
| 点击此处可从《第四纪研究》浏览原始摘要信息 | |
| 点击此处可从《第四纪研究》下载免费的PDF全文 | |