中文摘要：

近年来云南高原湖泊面临富营养化、渔业活动增强等多重环境压力的叠加影响,对湖泊的有效治理与生态修复急需对多重压力下生态系统的响应模式进行系统了解.现有研究表明在系统生产力和捕食压力的不同配置下,湖泊系统主要组成（如浮游动物）的响应特征可能出现差异且捕食压力可能随营养水平的变化而改变,目前对云南湖泊生态系统的研究主要集中于单一环境压力下的生态响应.本研究以目前分别处于重富营养和中-贫营养水平的滇池和抚仙湖为研究对象,应用湖泊沉积物记录进行多指标分析,探讨受外来鱼类影响下两个大型湖泊浮游动物长期响应模式的异同.通过象鼻溞生物量与个体大小等指标,重建了近百年来滇池与抚仙湖典型浮游动物的变化历史,结果表明随着湖泊生产力水平（如沉积物色素生产量）的增加,2个湖泊中象鼻溞生物量显著增加,同时物种相对组成出现明显变化（如Bosmina longispina被B.longirostris取代）,指示湖泊上行效应对浮游动物的控制作用.同时象鼻溞的生物量、壳长与触角长度的变化在1960s与1980s有明显降低的趋势,与同期外来鱼类（如银鱼）引入与渔业产量增加的时间一致.进一步应用多变量回归分析与方差分解方法来定量评价上行与下行效应对象鼻溞生物量变化的驱动强度,结果表明富营养化（沉积物色素）和捕食作用（象鼻溞壳长）对浮游动物长期变化的驱动强度比较相似（分别解释了生物量变化的77.25%和83.59%）,然而在滇池下行效应对象鼻溞生物量的独立影响比在贫营养的抚仙湖中更强（分别为15.46%和10.39%）,上行效应对象鼻溞生物量的影响在抚仙湖要明显强于滇池（分别为69.74%和19.67%）,而在滇池上行与下行效应的相互作用强度明显强于抚仙湖（分别为42.12%和3.46%）.结果表明随着湖泊营养水平的升高,浮游动物

英文摘要：

In recent years,lakes of Yunnan Plateau have increasingly experienced the pressure of multiple environmental stressors like eutrophication and fish invasion,as well as their synergic effects. To date,most studies have focused on the ecological impacts of a single stressor,in spite of the interaction of these multiple stressors. This paper selected Lake Dianchi and Lake Fuxian,which are currently hypo-eutrophic and oligo-mesotrophic respectively,and conducted multi-proxy analyses of lake sediments from both lakes. We aim to quantify the impacts of both eutrophication（ bottom-up control） and predation pressure（ top-down control） in driving the long-term changes of zooplankton production,and to compare the intensity of their single forcing and interaction between both lakes. Our results showed that both lakes experienced increased primary production（ i. e. the production of sedimentary pigments） since the mid-20 thcentury,which was consistent with the eutrophication history revealed by lake monitoring data. Concurrently,the production of zooplankton（ i. e. sedimentary bosminid production） increases significantly with a general trend of the oligotrophic taxon of Bosmina longispina replaced by B. longirostris found in both lakes. However,the bosminid production and body size（ i. e. carapace and antennule length）,displayed a decrease during the 1960 s and 1980 s,when exotic fish were introduced and / or established stable populations. With the methods of multiple regression and variance partitioning,our further analyses suggested that top-down control（ as indicated by bosminid carapace length） exerted stronger impact on zooplankton production at Lake Dianchi than at Lake Fuxian（ 15. 46% and 10. 39%,respectively）,while Lake Fuxian displayed a much stronger control of bottom-up（ represented by sedimentary pigment concentration） forcing than Dianchi（ 69. 74% and 19. 67%,respectively）. In addition,we found that the interaction between bottom-up and top-down is much more significant at La