人类活动和气候变化下干旱地区湖泊－博斯腾湖近200年来生态环境长期演化机制的研究

With the social and economic development and global climate change, China's northwest arid region lakes gradually trend to salinization and eutrophication, and environmental protection and sustainable development has increasingly become a prominent issue. To studies the impact of lakes salinization and eutrophication on ecology and environment of lakes, the combining methods of modern the limnology and paleolomnology are chosen to studied the long-term ecological and environmental succession of Bosten Lake in the past nearly 200 years. To track its ecological and environment changes in response to the interactive effects of climate change and human activities, succession of biological indies sediment (diatom, Cladocera Chirnomidae) are analized combining with chronology and muti -proxies of lacustrine sediment of Lake Bositeng, and successions of Lake Boseteng in the past 200 years are built. At the same time, the Nutrient levels is reconstructed with diatom and Chironomidae transfer function, and the succession sequence of past 200 years are compared with the modern environment and are modified to analyzes the Regularity and actors of long-term changes of Lake Bositeng. The paleolimnolocal data and climate reconstruction data and documental records in the Lake Bositeng basin are analyze by variance partitioning analysis and canonical correspondence analysis ane redundancy analysis, and the forcing factors of succession of Lake Bositeng are identified and quantified. The present study will be a universal guiding significance to carry out lake management of western arid and semi-arid areas in China,in other lakes

随着社会经济的发展和全球气候变化加剧，我国西北部干旱地区湖泊逐渐趋向咸化和富营养，水环境保护以及可持续发展越来越成为一个突出的问题。针对目前西部地区湖泊共同存在的湖泊咸化和富营养化等问题，本研究选择具有代表性的博斯腾湖作为研究对象，利用古－今湖沼学方法相结合的方法对其近200年来长期演化进行研究，通过系列浅钻沉积物多生物残体和环境代用指标的分析，结合硅藻/摇蚊-水体总磷转换函数，对照博湖现生的监测数据比较并矫正偏差，重建博斯腾湖生态环境演化的历史，研究其规律和阶段性特征，获得湖泊咸化和富营养化发生前的本底生态环境状况，评估不同演化阶段的生态环境质量；利用方差配置分析等方法定量区分人类活动和气候变化对湖泊环境的影响，确定博斯腾湖生态环境长期演化的驱动因素并定量其影响分量，本项研究的完成还将对我国水资源紧缺的西部干旱、半干旱地区其它湖泊的治理亦有着普遍的指导意义和广阔的应用前景。

随着社会经济的发展和全球气候变化加剧，我国西北部干旱地区湖泊逐渐趋向咸化和富营养，水环境保护以及可持续发展越来越成为一个突出的问题。针对目前西部地区湖泊共同存在的湖泊咸化和富营养化等问题，本研究选择具有代表性的博斯腾湖作为研究对象，利用古－今湖沼学方法相结合的方法对其近200年来长期演化进行研究。研究发现博斯腾湖目前全湖处于中营养状态，部分水域达到中富营养水平，人类活动的干扰和气候变化，博斯腾湖出现了咸化与富营养化两种趋势，对湖泊的环境功能存在显著威胁，湖泊生态系统结构有简化的趋势。综合硅藻和摇蚊种群组合和其他环境代用指标，结合历史资料以及其他研究结果，发现博斯腾湖近200年来环境变化受自然环境变化及人类活动干扰双重的影响。1950年前湖泊环境演变主要受自然因素影响，1950年后人类活动对湖泊生态环境变化起主导作用。其中，自然因素的影响主要表现为气候变化影响入湖径流量大小，从而影响湖泊水位、盐度、水质等理化性质，人类活动主要表现为工农业发展后导致湖泊富营养化，摇蚊和硅藻富营养化种类逐渐出现甚至占优，湖泊生态系统的结构遭到改变。本项研究的完成将对我国水资源紧缺的西部干旱、半干旱地区其它湖泊的治理亦有着普遍的指导意义和广阔的应用前景。