| Abstract | Varved lake sediments provide opportunities for high-resolution paleolimnological investigations that may extend monitoring surveys in order to target priority management actions under climate warming. This paper provides the synthesis of an international research program relying on > 150 years-long, varved records for three managed perialpine lakesi n Europe (Lakes Geneva, Annecy, and Bourget). The dynamics of the dominant, local human pressures, as well as the ecological responses in the pelagic, benthic, and littoral habitats were reconstructed using classical and newly developed paleo-proxies. Statistical modeling achieved the hierarchization of the drivers of their ecological trajectories.
All three lakes underwent different levels of eutrophication in the first half of the XXth century, followed by re-oligotrophication. Climate warming came along with a 2°C-increase in air temperature over the last century, to which lakes were unequally thermally vulnerable. Unsurprisingly, phosphorous concentration has been the dominant ecological driver over the last century.
Yet, other human-influenced, local environmental drivers (fisheries management practices, river regulations) have also significantly inflected ecological trajectories. Climate change has been impacting all habitats at rates that, in some cases, exceeded those of local factors. The amplitude and ecological responses to similar climate change varied between lakes, but, at least for pelagic habitats, rather depended on the intensity of local human pressures than on the thermal effect of climate change.
Deep habitats yet showed higher sensitivity to climate change but substantial influence of river flows. As a consequence, adapted local management strategies, fully integrating nutrient inputs, fisheries management, and hydrological regulations, may enable mitigating the deleterious consequences of ongoing climate change on these ecosystems. |
| Authors | Marie-Elodie Perga, Victor Frossard, Jean-Philippe Jenny, Benjamin Alric, Fabien Arnaud, Vincent Berthon, Jessica L. Black, Isabelle Domaizon, Charline Giguet-Covex, Amy Kirkham, Michel Magny, Marina Manca, Aldo Marchetto, Laurent Millet, Christine Paillès, Cecile Pignol, Jérome Poulenard, Jean-Louis Reyss, Frederic Rimet, Pierre Sabatier, Olga Savichtcheva, Florence Sylvestre and Valérie Verneaux |
| Text | 334701 2015 10.3389/fevo.2015.00072 Palololimnology cladocera diatoms High resolution paleolimnology opens new management perspectives for lakes adaptation to climate warming Marie Elodie Perga, Victor Frossard, Jean Philippe Jenny, Benjamin Alric, Fabien Arnaud, Vincent Berthon, Jessica L. Black, Isabelle Domaizon, Charline Giguet Covex, Amy Kirkham, Michel Magny, Marina Manca, Aldo Marchetto, Laurent Millet, Christine Pailles, Cecile Pignol, Jerome Poulenard, Jean Louis Reyss, Frederic Rimet, Pierre Sabatier, Olga Savichtcheva, Florence Sylvestre and Valerie Verneaux INRA, UMR CARRTEL, Universite Savoie Mont Blanc, ThononlesBains, France, UMRCARRTEL, University of Savoie Mont Blanc, Chambery, France UMR Chrono Environnement, Besaçon, France Environnements, Dynamiques et Territoires de la Montagne, University of Savoie Mont Blanc, Chambery, France Centre EauTerre Environnement, Institut National de la Recherche Scientifique, Quebec, QC, Canada Geochemistry and Geodynamics Research Center GEOTOP , Montreal, QC, Canada Centre National de la Recherche Scientifique, Aix Marseille Universite ,Institut de Recherche pour le Developpement, UM34 Centre Europeen de Recherche et d Enseignement des Geosciences de l Environnement ,Aix en Provence, France Consiglio Nazionale delle Ricerche Istituto pe rlo Studio degli Ecosistemi, Verbania Pallanza, Italy Le Laboratoire des Sciences du Climat et de l Environnement, Gif sur Yvette, France Varved lake sediments provide opportunities for high resolution paleolimnological investigations that may extend monitoring surveys in order to target priority management actions under climate warming. This paper provides the synthesis of an international research program relying on > 150 years long, varved records for three managed perialpine lakesi n Europe Lakes Geneva, Annecy, and Bourget . The dynamics of the dominant, local human pressures, as well as the ecological responses in the pelagic, benthic, and littoral habitats were reconstructed using classical and newly developed paleo proxies. Statistical modeling achieved the hierarchization of the drivers of their ecological trajectories. All three lakes underwent different levels of eutrophication in the first half of the XXth century, followed by re oligotrophication. Climate warming came along with a 2°C increase in air temperature over the last century, to which lakes were unequally thermally vulnerable. Unsurprisingly, phosphorous concentration has been the dominant ecological driver over the last century. Yet, other human influenced, local environmental drivers fisheries management practices, river regulations have also significantly inflected ecological trajectories. Climate change has been impacting all habitats at rates that, in some cases, exceeded those of local factors. The amplitude and ecological responses to similar climate change varied between lakes, but, at least for pelagic habitats, rather depended on the intensity of local human pressures than on the thermal effect of climate change. Deep habitats yet showed higher sensitivity to climate change but substantial influence of river flows. As a consequence, adapted local management strategies, fully integrating nutrient inputs, fisheries management, and hydrological regulations, may enable mitigating the deleterious consequences of ongoing climate change on these ecosystems. 3 Published version http //journal.frontiersin.org/article/10.3389/fevo.2015.00072/abstract articolo FRONTIERS2015.pdf Articolo in rivista Frontiers Media 2296 701X Frontiers in Ecology and Evolution Frontiers in Ecology and Evolution Frontiers in Ecology and Evolution Front. ecol. evol. aldo.marchetto MARCHETTO ALDO marinamarcella.manca MANCA MARINA MARCELLA TA.P04.016.004 Ecologia teorica e applicata degli ecosistemi acquatici |
