From the text...'Longleaf pine prevails along the Gulf Coast from Louisiana to west Florida, though it occurs throughout most of the balance of the Coastal Plain. Pure stands probably once occupied. half of the southern pine area. Longleaf pine grows on clay as well as sand regardless of fertility, the principal demand upon the site being for adequate soil moisture which is particularly limiting to growth when vegetative competition is severe. Yet this is typically a dry-site species, xero-mesic oak-hickory stands replacing it in soils with high water-holding capacity in clay layers. Longleaf pine is not found on wet sites except when droughts accompany abundant seed fall and fires that eliminated shrub shade. Hence, soil moisture and fire history are responsible for the occurrence of the several types: pure longleaf, long-leaf pine-slash pine, and longleaf pine-turkey oak (Soc. Amer. For., 1954). Loblolly and shortleaf pines mix with longleaf pine in loamy flatwoods, while southern red oak and sweetgum occur on drier sites. Longleaf pine is more shade-tolerant than slash pine (Mattoon, 1916), but less so than other southern pines. A fire-subclimax type, this species dominates the forest only as long as periodic fires occur. In pre-historic times, dead snags struck by lightning burned, setting grassy longleaf pine forests on fire. With fire exclusion, the natural range has been receding, giving way to slash pine along the eastern Gulf and Atlantic coasts, and to loblolly pine in the western part of the Gulf coastal area. Acreage decline is also due to (1) overcutting which left vast expanses without even a single seed tree, (2) hog grazing on seedlings rich in carbohydrates, and (3) brown-spot needle blight which effectively keeps seedlings in the grass stage for up to 25 years. Further decline is expected as fire protection improves and because slash pine plantations are easily established.'