We are seeking for a new PhD student to complete our group. Check the add there. Applications before June 30th.
Open PhD position on high-altitude lakes responses to climate change
Lexplore on the radio
RTS “On va vers le beau” makes a specific broadcast on Lexplore.
New paper led by Marttiina just fresh out from the press
We expect that the main components of global change (excessive nutrient inputs, climate warming) will modify the concentrations of CO2 in lakes and then their contributions to CO2 emissions. But, long-term datasets for lake datasets are too rare to systemtically assess how much and even in which direction. Using isotope analyses on microfossils remains, Marttiina and her coauthors could reconstruct how CO2 have changed over the last century at the surface of 7 Swiss lakes, that endured striking changes in nutrient inputs and climate warming. They could show that not all lakes are equally sensitive and that the amplitude and direction of changes in surface CO2 are conditioned by the drainage ratio (how much the catchment influence the lake functioning).
Rantala, M. V., Bruel, R., Marchetto, A., Lami, A., Spangenberg, J. E., & Perga, M.-E. (2021). Heterogeneous responses of lake CO2 to nutrients and warming in perialpine lakes imprinted in subfossil cladoceran δ13C values. Science of the Total Environment, 782, 146923. doi:https://doi.org/10.1016/j.scitotenv.2021.146923
Lake Geneva : the one you see now is quite different from the one Forel saw
Thought large lakes could not endure regime shifts? Our latest study by Rosalie Bruel used long-sediment cores to show that the luxuriant macrophytes forests described by Forel were lost just before the long-term monitoring program started. The lake we have monitored since then is an alternate stable state away from the one Forel was observing. The previous state was quite stable to 3°C changes in annual ambient atmospheric temperatures, the new state is, in contrary, quite sensitive. The legacy of past eutrophication is an hyper-sensibility to climate changes.
Do food webs persist under lake ice?
Don’t be mistaken. Things are not so quiet underneath the ice of frozen lakes… Some zooplankton species can persist under lake ice, but how do they cope with the extremely limiting food resources? Do they actually feed, but on what? Do they keep activity at minimal rate, to survive only from exhausting their fat stored during the previous good season? in which case, persistance of active species would not be equivalent to the persistance of an active food web under the ice…
Some answers in our paper soon to be published in Freshwater Biology: Fasting or feeding: a planktonic food web under lake ice.
