Opuntia in shallow, loose soils, such as on mountain slopes. "Opuntia" spreads into large clonal colonies, which contribute to its being considered a noxious weed in some places. Animals that eat "Opuntia" include the prickly pear island snail and "Cyclura" rock iguanas. The fruit are relished by many arid land animals, chiefly birds, which thus help distribute the seeds. "Opuntia" pathogens include the sac fungus "Colletotrichum coccodes" and Sammons' Opuntia virus. The ant "Crematogaster opuntiae" and the spider "Theridion opuntia" are named because of their association with prickly pear cacti. Like most true cactus species, prickly pears are native only to
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