Das Projekt "Charakterisierung von Plasmamembranen in Kiefernnadeln und Einfluss von Umweltstress auf ihre strukturellen und funktionellen Komponenten" wird vom Umweltbundesamt gefördert und von Universite de Geneve, Departement de Botanique et Biologie Vegetale durchgeführt. The characteristics of stream ecosystems in arctic, alpine and mountain streams are determined primarily by their water balance, that is the relative contributions of glacier-melt, snowmelt, rainfall runoff and spring flow (groundwater). Each of these sources generates a seasonal hydrological signature and runoff of different physical (temperature and suspended sediment load) and chemical quality. Thus, stream catchments comprise a complex spatial pattern reflecting the water balance from various sources. This pattern is highly sensitive to climatic change. From a synthesis of European and Alaskan literature, Milner and Petts (1994) proposed a conceptual model to predict the gradient of macroinvertebrate benthic communities in streams downstream of glacial margins. This model suggested that two principle variables, water temperature and channel stability, determine the occurrence of certain key macroinvertebrate taxa. One of the objectives of the proposal is thus to validate the Milner and Petts conceptual model and then to quantify the parameters of the model. These objectives are only possible by using a latitudinal and climatic transect of sites across Europe to undertake a functional analysis of the sensitivity of cold stream ecosystems to variations in water balance. The proposal encompasses a wide range of sites, from the Alps and Pyrenees in the south to Arctic areas on Iceland and Svalbard in the north. Their climates range from strongly oceanic to continental. In some of these areas the glaciers are retreating, in some they are advancing, while in others they are more or less stable. This project will enable the development of aquatic macroinverebrates as a predictive tool for sustainable management of such ecosystems and enable the sensitivity of arctic and alpine stream ecosystems to be assessed in relation to (I) climate change, (II) human impacts and (III) nature conservation objectives.