This layer provides a classification of New Zealand ecosystems according to fern composition. Generalized Dissimilarity Modelling was used to produce a model of biotic composition in relation ship to environment and biogeography. This model was used to transform and scale environmental layers to predict community composition. The transformed environmental layers were then used to classify New Zealand into areas of similar biotic composition. The biotic data used for this model include all fern taxa from NVS recce data and estimated community compositions from pollen data.