Kenneth A. Kershaw, Quantitative and Dynamic Ecology, American Elsevier, 1964

THE DOMINANCE BEHAVIOUR OF THE EIGHT MOST IMPORTANT TREE SPECIES AT THREE LEVELS OF THE ORDINATION

Each species shows a definite spatial 'centre of importance' (related to the number and size of the balls). Away from the centre the concentration and importance of a species diminishes, but not equally in different directions. The three axes are interpreted as: 1. Reflecting recovery from major past disturbance and shows a marked correlation with features of an increasingly mesic environment and with several soil factors—organic matter, pH, Ca, O, etc. 2. Related to drainage and soil aeration and shows correlation with soil water retaining capacity and ammonium ion concentration. 3. Related to recent disturbance and the influence of gap phase replacement.