Pinus serotina

Pinus serotina, the pond pine, black bark pine, bay pine, marsh pine, or pocosin pine,  is a pine tree found along the Southeastern portion of the Atlantic coastal plain of the United States, from southern New Jersey south to Florida and west to southern Alabama. Pond pine distribution may be starting to spread west towards Mississippi and Tennessee.

Description
This pine often has a crooked growth pattern and an irregular top and grows up to 21 m high, rarely to 29 m. The needles are in bundles of three or four, and 15 – long. Pinus serotina will grow needles and little branches directly from the trunk, similar to the Pinus rigida (pitch pine), but the pitch pines will only grow in drier areas. The Pinus serotina is very similar to the common Pinus taeda (loblolly pine), but the key differences are they have direct needle growth from the trunk, are smaller in size, and tend not to grow straight. The bark of the pond pine forms rough plates. They are a brownish-red color. The pond pines are not as cold hardy as the loblolly and pitch pines. It takes 18 years for the pond pine to reach full maturity. The almost round cones are 5 – long with small prickles on the scales. Its cones are usually serotinous, requiring fire to open. The pollen cones are cylinder-shaped with a yellow, brownish color, and are up to 1.8 inches long. Seed cones need two years to mature after pollination. In some cases, they will drop their seeds, but in most Pinus serotina, they will persist and hold their seeds. The color of the seed cones and seed scales is red-brown in color. The foliar sheaths measure 0.4 to 0.8 with long bases. The seeds are ovule in shape, being 0.2 and 0.24 in length, and have an angled tip colored a pale brown. For seeds to be used for regeneration, seed trees that are 23 to 25 cm (9 - 10 inches) in DBH and 30 years old are expected to produce 5,000 seeds.

Taxonomy
Pinus serotina was described in 1803 by Andre Michaux. Pinus is a large genus of evergreen conifer trees. The species name serotina is derived from the persistently serotinous cones that may remain closed for several years before they release their seeds. Historically this species has been viewed as a subspecies of Pinus taeda. Similarly Pinus serotina has also been considered a subspecies of Pinus rigida (Pinus rigida subsp. serotina (1880)).

Habitat
Pinus serotina is primarily found in wet and poorly drained sites, most commonly in or near swamps, ponds, bays, marshes, and pocosins. This species is often associated with long leaf pine, Pinus palustris, due to similar requirements for frequent fire and pond pines needs fire to germinate. Pinus serotina is commonly found in wet and poorly drained sites, but it will grow very well in mineral soils. Pond pines are very useful in preventing erosion and improving water quality. Pinus serotina, thrive in flatwoods, flatwoods bogs, savannas, and barrens. At the north end of its range, pond pine intergrades and hybridizes with pitch pine (P. rigida); it is distinguished from that species by longer needles and on average slightly larger cones. Some botanists treat pond pine as a subspecies of pitch pine. Pinus serotina habitat include mild and humid climates. The average temperature ranges from 45 degrees F to 80 degrees F. The more extreme temperature ranges recorded for Pinus serotina are -10 degrees F and 110 degrees F. The average annual precipitation for Pinus serotina is between 44 and 55 inches.

Ecology
Pinus serotina stands provide habitat and support for many wildlife species, particularly for birds and mammals in wetlands and flatland environments. The pond pine is intolerant of shade. In order for reproduction to occur, Pinus serotina needs fire in the form of intense scorching or defoliation. The buds are dormant and protected by the tree's thick bark. When parts of the tree are top killed by fire, epicortical buds can resume growth. 15 to 20 seed trees are needed per hectare (6 to 8 acres) for the sufficient seed set after fire. Without the heat from a fire the seed fall is limited by the serotinous cones of pond pine. Pond pine seedling growth is often limited by the moisture in the soil, lack of nutrients, and competition. Under poor growing conditions pond pine seedlings grow can as little as 30 cm (12 inches) or less per year.

Uses
Even though the Pinus serotina has poor form and relatively slow growth, it can produce economically valuable tree stands of for pulpwood and saw timber where other trees will not grow. Tan or green dyes can be obtained from the needles of the Pinus serotina. A vanillin flavoring is obtained from the byproducts of the pulpwood's resins. It is suggested that Pinus serotina might be a valuable remedy to treat the kidney, and can be administered as a rub or in a steam bath. Pinus serotina may be useful in treating diseases of the mucous membrane and respiratory complaints.

Diseases and other issues
Several species of bark beetles attack southern pines including pond pine, the beetles include the Southern pine beetle, three species of the Ips engraver beetles, and the black turpentine beetle. These beetle species grind through conducting tissues of their hosts. Phloem damage leads pine needles fading from green, to light green, and death of the tree. These trees also face the eastern pine weevil and are susceptible to wind damage. Pinus serotina also faces red heart disease (Phellinus pini), a fungal disease of pines.

Conservation statues
The primary threat to the Pinus serotina is habitat loss of wet flatlands, peat-rich soils, sandy wet flatlands, and pocosins. Pinus serotina, allows for trees to regenerate by coppicing. Thus disturbances (e.g. fire) are required for this species to persist and recruit. Pinus serotina, is listed by the IUCN Red List as a species of least concern (LC) for extinction.