The adventive flora of New Zealand

The ecological grouping (Decreaser and Increaser groups) of individual species was determined on two topographical units in the Highland Sourveld of the Orange Free State. For this purpose gradients were selected, giving special attention to fence‐line comparisons, vegetation at different distances from watering points and ungrazed vegetation. The ecological grouping (Decreaser and Increaser groups) of species on a grazing gradient differed not only for different topographical units, but also for sub‐habitats within a certain unit. Broad standardized groupings of species into Decreaser and Increaser groups are therefore scientifically wrong and of little practical use.