complex history of genetic relatedness. The following cladogram shows the phylogenetic relationships between the pine species as described in 2021. Distribution and habitat Pines are native to the Northern Hemisphere, and to a few parts from the tropics to temperate regions in the Southern Hemisphere. Most regions of the Northern Hemisphere host some native species of pines. One species (Sumatran pine) crosses the equator in Sumatra to 2°S. In North America, various species occur in regions at latitudes from as far north as 66°N to as far south as 12°N. Pines may be found in a very large variety of environments, ranging from semi-arid desert to rainforests, from sea level up to , from the coldest to the hottest environments on Earth. They often occur in mountainous areas with favorable soils and at least some water. Various species have been introduced to temperate and subtropical regions of both hemispheres, where they are grown as timber or cultivated as ornamental plants in parks and gardens. A number of such introduced species have become naturalized, and some species are considered invasive in some areas and threaten native ecosystems. Ecology Pines grow well in acid soils, some also on calcareous soils; most require good soil drainage, preferring sandy soils, but a few (e.g. lodgepole pine) can tolerate poorly drained wet soils. A few are able to sprout after forest fires (e.g. Canary Island pine). Some species of pines (e.g. bishop pine) need fire to regenerate, and their populations slowly decline under fire suppression regimens. Pine trees are beneficial to the environment since they can remove carbon dioxide from the atmosphere. Although several studies have indicated that after the establishment of pine plantations in grasslands, there is an alteration of carbon pools including a decrease of the soil organic carbon pool. Several species are adapted to extreme conditions imposed by elevation and latitude (e.g. Siberian dwarf pine, mountain pine, whitebark pine, and the bristlecone pines). The pinyon pines and a number of others, notably Turkish pine and gray pine, are particularly well adapted to growth in hot, dry semidesert climates. Pine pollen may play an important role in the functioning of detrital food webs. Nutrients from pollen aid detritivores in development, growth, and maturation, and may enable fungi to decompose nutritionally scarce litter. Pine pollen is also involved in moving plant matter between terrestrial and aquatic ecosystems. Wildlife Pine needles serve as food for