Objectif The objective is to strengthen the scientific knowledge about functional properties of brown dissolved organic matter (humic substances (HS)) in surface waters which can influence the acidification of softwater ecosystems and its reversibility, and can alter the impact of acidification on aquatic organisms. Specifically this project will address the questions to which extent humic substances: contribute directly to acidification; interact with other dissolved materials; and directly influence aquatic biota. The research will cover investigations on acidification processes, the effects of acid precipitation on soil minerals and soil organic matter as well as on the amounts of deliberated solutes from catchment soils into the surface waters. The role of HS in the acidification processes of aquatic ecosystems and its effect on aquatic biota will be studied through a large scale field experiment with whole catchment manipulation. In this international experiment, called HUMEX project, one half of a dystrophic lake and the corresponding catchment will be artificially acidified with water from a nearby lake (naturally low in salts and organic matter). The lake is divided by a water tight curtain from the other half which is serving as the unacidified control. Detailed studies will include : soil water in the catchment; surface and groundwater entering into the lake; chemical composition of lake water and of outflow water in particular regarding HS in the water column and in sediments; microbial decomposition of detritus, nutrient (phosphorous and iron) availability in dystrophic water in relation to acidification and HS; and impacts on bacterial, phytoplankton, zooplankton, macroinvertebrate, macrovegetation and fish communities. Champ scientifique natural sciencesbiological sciencesecologyecosystemsnatural sciencesearth and related environmental scienceshydrologylimnology Programme(s) FP2-STEP - Two specific research and technological development programmes (EEC) in the field of the environment STEP/EPOCH - STEP -, 1989-1992 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur ROYAL NETHERLANDS ACADEMY OF ARTS AND SCIENCE Contribution de l’UE Aucune donnée Adresse 6,Rijksstraatweg 6 3631 AC NIEUWERSLUIS Pays-Bas Voir sur la carte Coût total Aucune donnée Participants (6) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire Consejo Superior de Investigaciones Cientòficas Espagne Contribution de l’UE Aucune donnée Adresse 18-26,Jordi Girona 08034 Barcelona Voir sur la carte Coût total Aucune donnée Lunds Universitet Suède Contribution de l’UE Aucune donnée Adresse 221 00 Lund Voir sur la carte Coût total Aucune donnée Max-Planck-Gesellschaft zur Förderung der Wissenschaften eV Allemagne Contribution de l’UE Aucune donnée Adresse August-Thienemann-Straße 2 24306 Plön Voir sur la carte Coût total Aucune donnée NORWEGIAN INSTITUTE FOR WATER RESEARCH Norvège Contribution de l’UE Aucune donnée Adresse 19,Brekkeveien 19 0411 Oslo Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée UNIVERSITY OF HELSINKI Finlande Contribution de l’UE Aucune donnée Adresse 320,Paeaejaerventie 320 16900 LAMMI Voir sur la carte Coût total Aucune donnée UNIVERSITY OF LANCASTER Royaume-Uni Contribution de l’UE Aucune donnée Adresse Bailrigg LA1 4YQ LANCASTER /HIGH BANTHAM Voir sur la carte Coût total Aucune donnée