Know more

About cookies

What is a "cookie"?

A "cookie" is a piece of information, usually small and identified by a name, which may be sent to your browser by a website you are visiting. Your web browser will store it for a period of time, and send it back to the web server each time you log on again.

Different types of cookies are placed on the sites:

  • Cookies strictly necessary for the proper functioning of the site
  • Cookies deposited by third party sites to improve the interactivity of the site, to collect statistics

Learn more about cookies and how they work

The different types of cookies used on this site

Cookies strictly necessary for the site to function

These cookies allow the main services of the site to function optimally. You can technically block them using your browser settings but your experience on the site may be degraded.

Furthermore, you have the possibility of opposing the use of audience measurement tracers strictly necessary for the functioning and current administration of the website in the cookie management window accessible via the link located in the footer of the site.

Technical cookies

Name of the cookie

Purpose

Shelf life

CAS and PHP session cookies

Login credentials, session security

Session

Tarteaucitron

Saving your cookie consent choices

12 months

Audience measurement cookies (AT Internet)

Name of the cookie

Purpose

Shelf life

atid

Trace the visitor's route in order to establish visit statistics.

13 months

atuserid

Store the anonymous ID of the visitor who starts the first time he visits the site

13 months

atidvisitor

Identify the numbers (unique identifiers of a site) seen by the visitor and store the visitor's identifiers.

13 months

About the AT Internet audience measurement tool :

AT Internet's audience measurement tool Analytics is deployed on this site in order to obtain information on visitors' navigation and to improve its use.

The French data protection authority (CNIL) has granted an exemption to AT Internet's Web Analytics cookie. This tool is thus exempt from the collection of the Internet user's consent with regard to the deposit of analytics cookies. However, you can refuse the deposit of these cookies via the cookie management panel.

Good to know:

  • The data collected are not cross-checked with other processing operations
  • The deposited cookie is only used to produce anonymous statistics
  • The cookie does not allow the user's navigation on other sites to be tracked.

Third party cookies to improve the interactivity of the site

This site relies on certain services provided by third parties which allow :

  • to offer interactive content;
  • improve usability and facilitate the sharing of content on social networks;
  • view videos and animated presentations directly on our website;
  • protect form entries from robots;
  • monitor the performance of the site.

These third parties will collect and use your browsing data for their own purposes.

How to accept or reject cookies

When you start browsing an eZpublish site, the appearance of the "cookies" banner allows you to accept or refuse all the cookies we use. This banner will be displayed as long as you have not made a choice, even if you are browsing on another page of the site.

You can change your choices at any time by clicking on the "Cookie Management" link.

You can manage these cookies in your browser. Here are the procedures to follow: Firefox; Chrome; Explorer; Safari; Opera

For more information about the cookies we use, you can contact INRAE's Data Protection Officer by email at cil-dpo@inrae.fr or by post at :

INRAE

24, chemin de Borde Rouge -Auzeville - CS52627 31326 Castanet Tolosan cedex - France

Last update: May 2021

Menu Logo Principal CARRTEL INRAE CARRTEL INRAE USMB logo CARRTEL INRAE CARNOT logo

CARRTEL INRAE USMB

UMR CARRTEL

Centre Alpin sur les Réseaux Trophiques et Ecosystèmes Lacustre

PACHA

Start date : September 2019 

Description 

Inland surface waters modify and transfer large amounts of carbon (C) from watersheds, contributing significantly to the global C cycle and acting on the climate1,2. Continental and oceanic sedimentation is the main long-term storage mechanism for C exported by inland waters. However, the storage of C in continental sediments (reservoirs, rivers, lakes) has received much less attention than that of marine sediments, and the C-sources and the dynamics of C-sequestration remain poorly understood on a large scale, in particular concerning the action of biological productivity in carbon fixation1,3. In addition, long-term dynamics are still poorly evaluated, necessitating the use of geological archives and modelling.

The biogeochemical (pigments, DNA) and geochronological (e.g. 14C) study of lacustrine sedimentary archives enables the continuous documentation, at an annual or multi-year resolution, of the evolution of carbon sequestration by lakes and algal productivity over centuries to thousands of years4. The study of these sediment archives also makes it possible to document the sources of C inputs, associated to external sources that depend on C-eroded from watersheds5 (allochthonous C), and on lake primary production6 (Autochtonous C). However, it is unclear how these respective sources influence long-term C-sequestration, and it therefore seems urgent to address this issue, particularly with respect to the contribution of primary production that has received relatively little attention at the global scale over time scales multi-decadal to centennial7.

This doctoral research project is therefore focused on the study of control factors of carbon sequestration by lakes over long time, at regional and global scales. Through a multi-scale approach, we propose to consolidate a global and multi-proxy paleo-limnological database (ie of lacustrine sedimentary archives) in order to analyze the 300-years historical trajectories of primary production for 420 sites in the world and to determine which of the algal groups have contributed to total primary productivity over time, and what have been the effects on carbon transfer and its sequestration in sediments. This project will address for the first time on these scales of space and time the issue of the dynamics of biological communities interacting with the transfer of matter in lake -watershed systems. This project will also lay the foundations for a long-term numerical model to simulate primary production and lacustrine carbon fluxes, which will build on existing models developed by the AFB-Irstea Cluster. This project will be part of the CARRTEL research axis on carbon transfer in lakeside environment.

References

  1. Regnier, P. et al. Anthropogenic perturbation of the carbon fluxes from land to ocean. Nat. Geosci. 6, 597–607 (2013).
  2. Maavara, T., Lauerwald, R., Regnier, P. & Van Cappellen, P. Global perturbation of organic carbon cycling by river damming. Nat. Commun. 8, 15347 (2017).
  3. Weyhenmeyer, G. Large differences in the efficiency of large lakes to transform nutrients and pollutants from the watershed. in (2018).
  4. Dearing, J. A. et al. Extending the timescale and range of ecosystem services through paleoenvironmental analyses, exemplified in the lower Yangtze basin. Proc. Natl. Acad. Sci. 109, E1111–E1120 (2012).
  5. Tranvik, L. J. et al. Lakes and reservoirs as regulators of carbon cycling and climate. Limnol. Oceanogr. 54, 2298–2314 (2009).
  6. Sobek, S. et al. Organic carbon burial efficiency in lake sediments controlled by oxygen exposure time and sediment source. Limnol. Oceanogr. 54, 2243–2254 (2009).
  7. Taranu, Z. E. et al. Acceleration of cyanobacterial dominance in north temperate-subarctic lakes during the Anthropocene. Ecol. Lett. 18, 375–384 (2015).