Abstract
A conceptual model for the occurrence of common macrophyte species in different freshwater habitats in New Zealand is presented. The model is developed in two steps. First, a classification of freshwater habitats based on the level of disturbance frequency and resource supply in the habitats is performed. Second, a classification of common New Zealand freshwater macrophytes is made based on the appearance of relevant competitive species traits in different combinations of disturbance frequency and resource supply. From this we predict in which habitat each species is most competitive. We discuss how to test and refine the model, especially by gaining more knowledge about the presence and distribution of the plant species in relation to disturbance frequency, based on field and experimental studies. Benefits of a thorough predictive model in relation to the management practices and maintenance of macrophyte vegetation in lakes and lowland streams are discussed.