Classification and ordination of selected ponds of County Durham

Macro flora and macro invertebrates were sampled at 20 ponds in County Durham, and information on forty eight environmental variables was also collected for each site. The environmental variables, plant species records and numbers of each species of corixidae (Hemiptera-Heteroptera) and water beetles (Coleoptera) occurring in each pond were used as the basis of various methods of ordination and indicator species analysis. A preliminary classification of ponds into five groups is proposed. Information on the species and environmental features which characterize each group are presented.