A model of bracken (Pteridium aquilinum) growth and the effects of control strategies and changing climate.
A mechanistic physiological model for the growth of bracken has been developed which describes its yearly cycle in terms of three compartments: frond biomass, rhizome tissue biomass and rhizome carbohydrate. Difference equations for various processes (including rhizome respiration, tissue senescence, photosynthesis and fluxes between compartments) are presented. These are combined to obtain equations for the three compartments for each stage in the yearly cycle of bracken growth. Collectively, these equations constitute the bracken growth model. The model can be used to predict the effects of different control measures on the biomass present in the stand. As a number of environmental factors are involved in the model, the effects of changes in these variables can be predicted. The deficiencies of the model are discussed and these emphasize areas where research on bracken should be focused.