AL-PE PROJECTS - WATER CHEMISTRY AND CRITICAL LOADS

Water chemistry data on which all the investigations in the AL:PE 1 (A cidification of Mountain Lakes: Palaeolimnology and Ecology) and AL:PE 2 (Remote Mountain Lakes as Indicators of Air Pollution and Climate C hange) projects are based, are available for 28 lakes in U.K. (Scotlan d), Italy, Norway and France (AL:PE 1) and in Svalbard (Norway), Irela nd, Austria, Spain, Portugal Poland, Slovakia, Slovenia and Russia (AL :PE 2). The results show high sulphate concentrations in some mountain lakes in all the countries. Nitrate and sulphate concentrations have different distribution patterns among the sites. A gradient in acidifi cation from north (Norway) to central Europe (via U.K. to Italy) is id entified for the AL:PE lakes by means of multivariate data analysis. C ritical loads and their exceedance are calculated, where sufficient in formation is available, both according to the leaching of S, and of S plus N fi-om the catchment. The pattern of critical load exceedance de monstrates an increasing importance of nitrate from Norway via U.K. to Italy. Leaching of N was of considerable importance to the acidificat ion of lakes in the Italian Alps. The projects receive financial suppo rt from the European Union.