王荣2,
羊向东2,,,
陈旭3,
赵雁捷4,
杨浩1
1. 南京师范大学地理科学学院, 江苏 南京 210046
2. 中国科学院南京地理与湖泊研究所, 湖泊与环境国家重点实验室, 江苏 南京 210008
3. 中国地质大学(武汉)地球科学学院, 湖北 武汉 430074
4. University of Southampton, UK Southampton SO171BJ, UK
基金项目: 国家自然科学基金重点项目(批准号:41530753)、国家自然科学基金面上项目(批准号:41472314)和中国科学院青年创新促进会专项项目(批准号:2017364)共同资助
详细信息
作者简介: 徐敏, 女, 30岁, 博士后, 自然地理学专业, E-mail:min.minxu@163.com
通讯作者: 羊向东, E-mail:xdyang@niglas.ac.cn
中图分类号: Q949.27+1;P941.78收稿日期:2018-03-09
修回日期:2018-05-05
刊出日期:2018-07-30
Regime shift revealed by diatom records in typical big Yangtze shallow lake(Chaohu Lake) and its implication for management
Xu Min1,,Wang Rong2,
Yang Xiangdong2,,,
Chen Xu3,
Zhao Yanjie4,
Yang Hao1
1. School of Geography Science, Nanjing Normal University, Nanjing 210046, Jiangsu
2. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, Jiangsu
3. School of Earth Science, China University of Geosciences(Wuhan), Wuhan 430074, Hubei
4. University of Southampton, Southampton SO17 1BJ, UK
More Information
Corresponding author: Yang Xiangdong,E-mail:xdyang@niglas.ac.cn
MSC: Q949.27+1;P941.78--> Received Date: 09 March 2018
Revised Date: 05 May 2018
Publish Date: 30 July 2018
摘要
摘要:近几十年来,气候变化与人类活动显著影响了长江中下游浅水湖泊生态系统状态,导致服务功能急剧退化。对湖泊生态系统状态转变过程的深入理解是进行科学管理的重要依据。文章以大型浅水湖泊——巢湖为例,利用硅藻作为系统状态的替代指标,并结合多指标记录探讨了过去150年来巢湖生态系统转变过程。研究表明,湖泊水动力、营养和温度分别在不同时间尺度上驱动了巢湖生态系统状态变化,使其抵抗力下降;营养是触发1970s末期巢湖从清水态突变至浊水态的主要因素,而增温使这一转变进一步恶化。对比巢湖和太白湖的研究发现,大型和小型湖泊稳态转换的触发因素和维持机制有明显区别,建议根据不同湖泊生态系统状态长期变化过程和驱动因素施行针对性的管理措施。
关键词: 稳态转换/
巢湖/
长江中下游/
古湖沼/
湖泊管理
Abstract:In recent decades, shallow lakes in the middle and lower reaches of Yangtze River Basin(MLYB) are significantly influenced by climate change and human activities, probably rendering ecological regime shifts with degraded lake ecosystem services. Improved understanding of regime shifts and their transforming processes in shallow lakes is important for proper lake management. In this study, we focus on a typical big shallow lake in the MLYB——Chaohu Lake(31°25'28″~31°43'28″N, 117°16'54″~117°51'46″E), and take use of diatom as the proxies to show the ecological regime shifts in lakes. Two sediment cores, C1(31°35'47″N, 117°23'58″E) and C20(31°32'08″N, 117°37'12″E) were taken with a piston corer in the deepest part of Chaohu Lake in 2007 and 2009, respectively. C1 core is the main core, conducting multi-proxies analysis(including chronology, TOC, particle sizes, elements and diatom); while C20 core is the supplementary one, conducting only diatom identification to compare with the results in C1 core. Besides, historical documents including climate change(annual temperature and precipitation), hydrologic data(dam construction and annual average water level), water resources(vegetation coverage, TP, TN and fish production), and social-economic data(GDP, cropland, population and consumption of fertilizer) in Chaohu Lake and its catchment were also collected. By combining historical documents and palaeolimnological records, the specific ecological regime shifts and its transforming processes were analyzed in Chaohu Lake since 1850. Results of diatom assemblages using STARS methods based on PCA scores of diatom in both C1 and C20 cores reveals that, at least a regimes shift took place in late 1970s in Chaohu Lake, showing high regime shift index at that time. Redundancy analysis(RDA) reveals that weakened hydrodynamics, increased nutrients and climate warming posed effects on Chaohu's ecological states in different time periods, rendering the loss of its resilience. However, increased inputs of nutrients were the main driving forces of the ecological regime shift, which made Chaohu Lake change into current turbid water state from clear water state. And not only that, climate warming further aggravated this change afterwards. By comparing the results of ecological regime shifts in Chaohu and Taibai Lake, which are typical big and small lakes in MLYB respectively, it shows that the driving forces of ecological state change and regime shift processes are different in above two lakes. That means targeted management measures are necessary to lakes with different size and characteristics on temporal perspective.
Key words:regime shift/
Chaohu Lake/
the middle and lower reaches of Yangtze River Basin(MLYB)/
palaeolimnology/
lake management
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