ECOLOGICAL CLASSIFICATION OF MIRE IN THE SANJIANG PLAIN
三江平原沼泽的生态分类

This paper makes an approach to ecological classification of mire in the Sanjing Plain according to the view of ecology, selecting nine indexes of mire ecosystem, and dy means of principal component analysis, cluster analysis and discriminant analysis.The author considers that the aim of mire classification is to reveal essential properties of mire ecosystem and differences of mire formation and development. We not only try hard to reflect essential dif ferences among mire types, but also make great efforts to explore quantity scale measuring difference among mire types. Mire classification must be accor ding to essential properties of mire ecosystem, which are important elements for flows of energy and material in mire ecosystem.On the basis of classifi-catioh principle and method mentioned above, the mire in the Sanjiang Plain can de grouped into two types (seasonal water-logged mire and perennial water-logged mire) , four subtypes and eight dodies.This method is favourable for translating interrelationship of multidimensional space among mires which can't be illustrated in plane, into illustration in twodimen-sional figure, and measuring qualitatively differentiations in mire types and setting up discrimination mathmatics models of classification for unknown types of mire.In addition,the author suggests some indexes of mire eco-elassification. namely microgeomorphological index, vegetation type, clay content of sediment, origanic content, pH of plant residual laver by quantity. The eco-classi-fication has a certain significance in guiding for exploiting and utilizing mire scientifieally.