Quantitative classification and ordination of wetland vegetations in the reaches of the Hutuo River

TWINSPAN and DCA were combined to classify and collate seventy five quadrats of the wetland vegetations in the Hutuo River into 16 associations. The first axis in the ordination by DCA expressed the gradient of soil moisture while its second axis depicted the changes of soil types. The ordination diagram of the dominant species by DCA was similar to the one of the quadrats by DCA to a large extent and the distribution of the dominant species determined the distribution of the associations in a large measure.