Recent developments in the study of relations between ecological phenomena have consequences for studies of succession and species richness. Grime (1979) gives an ordination of plant species with respect to the strategies with which they are adapted to classified environments. The environments are characterized by ‘stress’ (S), ‘disturbance’ (D) and ‘competition’ (C). In this ‘environmental triangle’ phytocoenoses can be classified as well. When relating this ordination with vegetation dynamics and species richness, some problems are met. According to Grime there is a development from ‘D’, mostly over ‘C’, to ‘S’. Since species diversity is low in an ‘S’-environment, there should be maximum species richness in an intermediate stage of succession. Indeed this is in accordance with theories and observations of Connell and others, but in contradiction with e.g. Whittaker’s (1975) observation of a decrease with time of nutrient- and microclimate-stress and an increase of diversity.