Part 1 Monitoring:- Long Term Development of Element Budgets in a Norway Spruce (Picea abies (L.) Karst.) Forest of the German Solling Area; B. Manderscheid, E. Matzner, K.-J. Meiwes, Y. Xu. Ion Mass Budgets for Small Forested Catchments in Finland; M. Forsius, S. Kleemola, M. Starr, T. Ruoho-Airola. Mid-Term Trends in Acid Precipitation, Streamwater Chemistry and Element Budgets in the Strengbach Catchment, Vosges Mountains, France; A. Probst, B. Fritz, D. Viville. Spatial and Temporal Variability of Algal and Lichen Epiphytes on Trees in Relation to Pollutant Deposition in Sweden; S. Brackenhielm, L. Qinghong. Comparison of Field Methods in Vegetation Monitoring; S. Brackenhielm, L. Qinghong. Historical Rates of Atmospheric Pb Deposition Using 210Pb Dated Peat Cores: Corroboration, Computation, and Interpretation; M.A. Vile, M.J.V. Novak, E. Brizova, R.K. Wieder, W.R. Schell. Part 2 Catchment Manipulations and Biogeochemical Studies:- Solute Fluxes and Sulfur Cycling in Forested Catchments in SW Germany as Influenced by Experimental (NH4)2SO4 Treatments; K.H. Feger. Randomized Intervention Analysis of the Response of the West Bear Brook Watershed, Maine, to Chemical Manipulations; V. Uddameri, S.A. Norton, J.S. Kahl, J.P. Scofield. Stream Chemistry Impacts of Conifer Harvesting in Welsh Catchments; B. Reynolds, P.A. Stevens, S. Hughes, J.A. Parkinson, S. Weatherley. Biotic and Abiotic Processes Controlling Water Chemistry during Snowmelt at Rabbit Ears, Rocky Mountains, Colorado, U.S.A.; N.E. Peters, G. Leavesley. The Relationship between Dissolved Organic Matter and Percolation Water Chemistry in Northern Finland; A.-J. Lindroos, J. Derome, K. Niska. Retention and Mobility of Cations in a Small Peatland - Trends and Mechanisms; N.R. Urban, E.S. Verry, S.J. Eisenreich. Part 3 Isotopes as Tracers:- Sulfur Isotope Dynamics in a High-Elevation Catchment, West Glacier Lake, Wyoming; J.B. Finley, J.I. Drever, J.T. Turk. Transformation of Simulated Wet Sulfate Deposition in Forest Soils assessed by a Core Experiment Using Stable Sulfur Isotopes; J. Prietzel, B. Mayer, H.R. Krouse, K.E. Rehfuess, P. Fritz. Sulfur and Oxygen Isotope Ratios in Sulfate during an Acidification Reversal Study at Lake Gardsjon, Western Sweden; C.-M. Morth, P. Torssander. d34S, d18O, and dD in Shallow Groundwater - Tracing Anthropogenic Sulfate and Accompanying Groundwater/Rock Interactions; C. van Donkelaar, I.E. Hutcheon, H.R. Krouse. Modeling Excess Sulfur Deposition on Wetland Soils Using Stable Sulfur Isotopes; M.D. Morgan. The Use of Natural Strontium Isotopes as Tracers in Environmental Studies; G. Aberg. Modelling - Modelling Perspective of the Deforestation Impact in Stream Water Quality of Small Preserved Forested Areas in the Amazonian Rainforest; M.C. Forti, C. Neal, A. Jenkins. Long-Term Sulfate Dynamics at Lange Bramke (Harz) Used for Testing Two Acidification Models.