Carnivorous plant often waterlogged, which favours the production of toxic ions such as ammonium, and its pH is an acidic 4 to 5. Ammonium can be used as a source of nitrogen by plants, but its high toxicity means that concentrations high enough to fertilise are also high enough to cause damage. However, the habitat is warm, sunny, constantly moist, and the plant experiences relatively little competition from low growing "Sphagnum" moss. Still, carnivores are also found in very atypical habitats. "Drosophyllum lusitanicum" is found around desert edges and "Pinguicula valisneriifolia" on limestone (calcium-rich) cliffs. In all the studied cases, carnivory allows
Plant functional type Plant functional type Plant functional types (PFTs) is a system used by climatologists to classify plants according to their physical, phylogenetic and phenological characteristics as part of an overall effort to develop a vegetation model for use in land use studies and climate models. PFTs provide a finer level of modeling than biomes, which represent gross areas such as desert, savannah, deciduous forest. In creating a PFT model, areas as small as 1 km are modeled by defining the predominant plant type for that area, interpreted from satellite data or other means. For each plant functional type, a number of