首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Rising variance and abrupt shifts of subfossil chironomids due to eutrophication in a deep sub-alpine lake
Authors:Simon Belle  Virgile Baudrot  Andrea Lami  Simona Musazzi  Vasilis Dakos
Institution:1.UMR CNRS 6249, Laboratoire de Chrono-Environnement,Université de Bourgogne Franche-Comté,Besan?on,France;2.Center for Limnology, Institute of Agricultural and Environmental Sciences,Estonian University of Life Sciences,Tartumaa,Estonia;3.CNR,Istituto per lo Studio degli Ecosistemi,Verbania,Italy;4.Institute of Integrative Biology, Center for Adaptation to a Changing Environment,ETH Zürich,Zurich,Switzerland;5.Institut des Sciences de l’Evolution de Montpellier (ISEM), BioDICée team, CNRS,Université de Montpellier,Montpellier,France
Abstract:In response to anthropogenic eutrophication and global warming, deep-water oxygen depletion is expected to have large effects on freshwater lake biogeochemistry and resident communities. In particular, it has been observed that deep-water hypoxia may potentially lead to regime shifts of lake benthic communities. We explored such community shifts by reconstructing a high-resolution subfossil chironomid record from a sediment core collected in the sub-alpine lake Remoray in France. We identified an abrupt shift in chironomid composition triggered by the collapse of the dominant Sergentia coracina-type chironomids around 1980. We found that the collapse of Sergentia coracina type was coupled to a gradual increase in organic matter content in lake sediments caused by eutrophication. We concluded that the most probable cause for the collapse of Sergentia coracina type was a change in oxygen concentrations below the minimal threshold for larval growth. We also analyzed trends in variance and autocorrelation of chironomid dynamics to test whether they can be used as early warnings of the Sergentia collapse. We found that variance rose prior to the collapse, but it was marginally significant (Kendal rank correlation 0.71, p = 0.05), whereas autocorrelation increased but insignificantly and less strongly (Kendal rank correlation 0.23, p = 0.25). By combining reconstructions of ecosystem dynamics and environmental drivers, our approach demonstrates how lake sediments may provide insights into the long-term dynamics of oxygen in lakes and its impact on aquatic fauna.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号