6Berchtel,H.M.Monitoring wet deposition in forests: Puantitative and qualitative aspects [C] Report No.21in the Air Pollution Report Series of ths Environmental Research progranm of the Commission of the European Communrities,Brussels,1989,39~63.
7Brechtel,H.M.and H.M.Fuehrer.Importance of fo rest hydrological ‘benchmarkcatchments' in connectionwith the forest decline problem in Europe [J] .Agri For.Meter,1994,72: 81~89.