3Kleinn C, Dees M, Polley H. Forest Inventory and Survey Systems in Germany. Federal Ministry of Food, Agri-culture and Forestry, Bonn, 1998
4Joint Research Centre.Commission the European Communities, World Forest Watch Conference Proceedings. Brazil, May 27～29,1992
5Fischer R, De Vries W, Seidling W, Augustin S. Forest condition in Europe. Federal Research Centre for Forestry and Forest Producs(BFH). Bonn. 1999.31
7European Commission(EC) European programme for the intensive monitoring of forest ecosystems. General information on the permanent observation plots in Europe(level II). EC. 1996.85
8ICP(ed.)Manual on methodologies for harmonized sampling, assessment, monitoring and analysis of the effects of air pollution on forests. Programme Coordinating Centres east and west of the international cooperative programme on assessment and monitoring of air pollution effects on forests. 1986.92
9Programme Coodinating Centres(eds). Manual on methods and criteria for harmonized sampling, assessment, monitoring an analysis of the effects of air pollution on forests. Hamburg 1994:177
10Maser Chris. The Redesigned Forest. Stodart Publishing Co Limited. Toronto, Canada. 1990.223
