Comparison of ordinations of some apennine forest communities based on different characters and methods

In the course of numerical ordinations of Apennines woodlands, the problem arose of different performance of ordination methods, using different character sets and methods. To reveal underlying trends and relationships, 47 ordinations are jointly examinated, corresponding to combinations of 6 methods and 8 character types. The Spearman formula has been used to measure the similarity between different ordinations. The ordinations based on families are, on the average, the most similar to the other ones irrespective to the method used. The ordination based on detailed life forms (growth forms) are the least similar to the other ordinations. Ordinations based on the same character set and different methods could be different as well as ordinations based on different character sets and the same method. The suggested procedure can be the basis to select among different ordinations those explaining complementary informations