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UMR Carrtel Research Center on Trophic Networks and Lake Ecosystems. Unit Lake Observatory Some results. Bernard MONTUELLE. 1-1. Global scientific context. functionning of alpine lakes ecosystems related to their watershed and the atmosphere
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UMR Carrtel Research Center on Trophic Networks and Lake Ecosystems • Unit • Lake Observatory • Some results Bernard MONTUELLE
1-1. Global scientific context • functionning of alpine lakes ecosystems related to their watershed and the atmosphere • the effect of drivers , especially in the context of the present re-oligotrophisation dynamics and the climate change. • - 3 Sub systems and specific functionnings • Fluxes and internal exchanges • - External drivers and exchanges Climate Atmosphere T, light, deposits, Watershed- rivers Lake Land Uses Pollutions Flux./proc. soils ACTIVITES HUMAINES flux./proc. Flux./proc Water uses (fishing, recreational…) Regulations Standarts Integers the global change issues
1-1. Global scientific context Issue 1: Fluxes and processes at the interfaces ATMOSPHERE T, lumière, dépôts Bassin versant - affluents ► biogeochemical hot spots ► upstream-downstream fluxes ► fluxes modelling flux sols Issue 2: Structuring ecological processes Lac ► role of biodiversity ► biological models ►productivity- trophic fluxes ►ecotoxicology Biodiversity 3 organisation levels flux flux Functions Structure usages (pêche…) ► measurements ► quality indicators ► helping managers Issue 3 : Quality and management of the lakes and their ressources (environmental drivers changes)
2 – Operational issues Taking into account the managers/stakeholders questions Léman • 1950-1980 • * eutrophication • 1980-1990: *control of P fluxes • * re-oligotrophication Annecy Bourget Current questions (Ministery –Water Agency –Lake managers) • Re-oligotrophisation and climate vs fishing • Micropollutants (new or old) Changes of land uses (practices..) • Gobal management (lake+watershed) • Lake uses: • fishing • water resources • recreational • ecological services
3.1 The Unit and it’s scientific topics Thonon Chambéry RITOXE group: Fish Resources and Ecotoxicology of Lake Ecosystems (8) Watershed group: Watershed, fluxes, sediments (5) BIO-FEEL group: Biodiversity, Functions and Evolution of Lake Ecosystems (5) 45 full time 20 scientists 10PhD + post Head (1) Biodiversity and Molecular Biology Group (5 ) Sampling group(5) Chemistry lab(4) Outdoor experimental devices (2) Technical group (University of Savoie(3 ) Secretariat and Accounting (2) Computing and database (2) Workshop (2) Resource Center(1) Environmental Research Observatory
3.2 The Unit and it’s scientific topics ATMOSPHERE T, lumière, dépôts Bassin versant - affluents Group WaterShed: Transferts and functionningat interfaces Main topic: The Watershed as a transfer system to the lakes ♦ Functional spatialization of watershed ♦ Fluxes from terrestrial to aquatic ecosystems flux sols Lac Group » Biodiv- Funct »: Ecologicalprocesses and biologicalresponses Main topic: « Functionning and regulation of trophic networks» ♦ Pelagic communities ♦ Functional role of biodiversity flux flux Group « Fish & Ecotox »: Environmentalquality and Resources management usages (pêche…) Main topic:« Halieutic and stocking » ♦ Drivers of fish productivity (lakes and rivers) Main topic:« Algal and microbial ecotoxicology (biofilms, ..) » ♦ Contamination dynamics and impacts (pesticides)
3.3 The Unit and it’s scientific topics ACADEMIC (60 to 70 %) ► Producing generic knowledges (25 internat. papers/year + books) ► Building environmental Observatory: Alpine Lake Observatory ► Contributing to scientific networks RESULTS for SOCIO-ECONOMIC Instances and Public stakeholders (20%) ► Expert reports (Soils, Taxonomy), study reports, assessments,.. ► Decision-making assistance, developing partnerships (lakes, fishing, agriculture),producing documents ( technical guides, reports, …) RESULTS for education and training for research (<10%) ►University and engineer Schools. ►PhD formation ►PhD: ± 3/year
The Environmental Research Observatory « Alpine Lakes » (LTER) Léman Mesotroph (re-oligotrophisation ±1950 ± 1980 ± 1990 Annecy Oligotroph Le Bourget Mesotroph (re-oligotrophisation) • OBJECTIVES • Organize data collection, their storage, their use and their accessibility • Scrutinizing, understanding and modelling the trajectories and the ecological mechanisms controling the lake systems exposed to changes in anthropic and climatic pressures, at a 10 years time steps ».
- Long term surveys • Physicochemical and biological processes • controling water quality • Ecological trends • Consequences of global change Long termlimnology > 10 years Short and midtermprocesses Observatory 1< < 10 years Associatedprojects - Small mountains lakes - Micropollutants ecodynamics
Database Parameters - Physico-chemistry - Phytoplancton - Zooplancton - Bacterio & virioplankton - Chlorophyll - Primary production - Probes - Weather - Fish catches (annual) Information Systems – data base data Public access 10
Historical data Léman 1980 2000 1960 1970 1990 1920 2010 Annecy Bourget On paper ………………………………………………. General conditions On paper…………………………………………………………………. Transparency (Secchi) Meteo data Physico-chemistry {…..on paper …………….} Primary production Phytoplancton Bacterioviroplancton Zooplancton (net 1) Zooplancton (net 2) Fishessurveys Perch O+ Flurorometric probe Multiparameters Probes
Long term dynamics of lakes: Eutrophication - Reoligotrophication Increasing pollution Control of wastewater µg/l PO4 120 100 BOURGET 80 LEMAN 60 40 ANNECY 20 0 59 62 68 71 74 77 80 83 86 89 92 95 56 65 98
Long term dynamics of lakes: Trophic network changes Phosphorus = limiting factor Lake Leman Top-Down control 350 300 250 Changes in fish diversity (oligotrophy) Réponse Réponse Catches (tons) 200 Abondance Abondance 150 100 50 Coregonus albula 0 Temps 300 Biovolume (ml.m-2) Réponse Réponse 250 Abondance 200 Abondance 150 100 100 Temps 80 50 60 0 Réponse Réponse 3.7 40 Abondance Abondance Log (Biov+1) (µg.l-1) 3.5 20 3.3 0 3.1 Temps Temps 2.9 Effet 2.7 Effet PO4 2.5 Abondance Abondance 04 74 80 86 92 98 PO4 (µg/L) Temps Temps 74 80 86 92 98 04 Bottom -up control Anneville et al., 2007 Journal of¨Plankton Research)
Thank you for attention LACS http://www.dijon.inra.fr/thonon