LEAFS logo
Longleaf Ecology and Forestry Society  
line decor
line decor


Longleaf Ecosystem

         The longleaf ecosystem is now one which has very nearly disappeared, at least in its unaltered state.  A few remnants are left in parks, nature preserves, and state and national forests, but these are only a small fraction of the original acreage.  It is fitting, perhaps, to begin a description of the ecosystem by trying to answer the question: What happened to it?
         Longleaf pines once covered an estimated 70,000,000 acres in the coastal plain of the southeastern United States.  Today only 1,500 acres or about .002% of virgin pre-settlement longleaf pine forest remains.  Even if second growth forests and much-degraded longleaf pine plantations are counted, there is now only something on the order of 14% of the original acreage of longleaf pines.  The reduction in the amount of longleaf pine acreage was gradual.  Perhaps it is on account of this that the decline went unnoticed for so long.  Or perhaps it is on account of much of the decrease having occurred in the days before the awakening of America’s ecological awareness.

Current range of the longleaf 
In any event, accessible trees were cut for timber starting in colonial days.  Then, after an era when turpentine was important, large new areas were opened to logging with the expansion of southern railways, and throughout the early 1900s vast tracts of virgin longleaf pines were cut.  Often the cut-over timber land was converted to agriculture.  When it finally became apparent to the timber industry that the supply of trees was not inexhaustible, pine plantations were established, although the pine of choice was the sometimes more rapidly growing slash pine.  But if there is one single cause for the decline of longleaf pine in natural stands, it is Smoky the Bear.
         Natural fires -- caused by lightning strikes -- have been a part of the southern woodlands for many thousands of years.  Once a fire started, with no roads or other man-made obstacles to stop it, it could burn for miles.  Only those plants and animals with some defense mechanisms against fire could survive the frequent onslaughts. 


Longleaf pine and a whole range of associated organisms evolved so as to not only withstand fire, but to be dependent on it for their survival.  In order for longleaf pine seeds to germinate and grow, they must fall on open bare mineral soil, cleared by fire.  In the absence of fire, too many pine needles build up as ground litter and keep longleaf seeds from sprouting.  Also, shade from a thick understory can kill longleaf seedlings.  If this happens, as the mature longleaf pines die -- at an age of several hundred years -- they are replaced by broadleaved trees, such as oaks or hickories, and the whole ecosystem changes.  This is the well-known ecological principle of succession.
         What has this got to do with Smoky?  Starting in the 1920s and continuing until only recently, fire suppression was an important -- if not the dominant -- forestry management tool.  Throughout virtually the entire natural range of the longleaf pine, a concentrated effort was made to eliminate fire.  Consequently, the species failed to reproduce and succession occurred.  This result, coupled with the conversion of pine plantations to other species -- including slash pine, shortleaf pine, and loblolly pine -- caused the decline of longleaf acreage to accelerate.
         Today the role of fire in forest ecology is better understood.  Prescribed burning is more often used by forest managers for a variety of purposes, and often the results of such burning are similar to those which formerly occurred following natural fires.  Where the longleaf pine ecosystem is still intact, the use of prescribed burning ensures its survival.  Here in Florida, these areas are mostly limited to state parks, game lands, nature preserves, and parts of some state and national forests.  There is comparatively little longleaf pine acreage remaining in the hands of Florida's private landowners, and of what little there is, only a fraction is subjected to prescribed fire.  But where fire continues to play a part, one can find examples of the longleaf ecosystem.
Across the southeastern United States, the longleaf dominated ecological communities encompass a variety of soil types and moisture regimes.  The LEAFS sites are located in the part of Florida where the most prevalent type of community is known as pine flatwoods. 

Pine flatwoods

The name is descriptive, as this ecosystem is characterized by a low flat topography with poorly drained acidic sandy soil.  As the name also indicates, pines are the dominant tree, and broadleaved trees are reduced to a minor role.  In addition to longleafs, the other characteristic pines of flatwoods are slash pines and pond pines.  All of these may occur in pure stands or mixed together in different combinations and densities.  A variety of factors determines the precise mix of pines, including climate, latitude, soil types, hydroperiod, and fire regime.  But in general, pond pine will occupy the lowest and wettest sites, then slash pine, and finally longleaf on the better-drained and more frequently burned sites.

The shrubs growing in association with longleafs in pine flatwoods will also vary, again depending on a variety of factors.  However, saw palmetto is often the dominant shrub, frequently mixed with gallberry.  Wiregrass and running oaks appear in openings, as may huckleberries, blueberries, and hairy laurel or wicky.  Other common shrubs are fetterbush, stagger bush, wax myrtle, and tarflower.  More open stands allow a variety of herbaceous species to flourish.  In addition to grasses, various species of lily, deer tongue, goldenrod, asters, and violets are often encountered.  Bracken fern can be common and in early spring the flowers of the vine yellow jessamine are evident.  Depending on the frequency of fires, the understory may appear to have a layered effect, as many of the shrubs mentioned can reach heights of 10-12 feet, while others stay closer to the ground.  In any event, in mature longleafs, there is a noticeable gap between the top of the shrub layer and the tree canopy.

When wildflowers are blooming, butterflies and other insects might be the most noticeable wildlife in pine flatwoods.


At other times, birds likely will be most evident.  Perhaps the most common bird is the eastern towhee.  Other common year-round resident birds in the understory are common yellowthroats and Carolina wrens.  Common birds high in the pines include pine warblers and brown-headed nuthatches, and sometimes bluebirds.  The bird most often associated with the longleaf ecosystem is the red-cockaded woodpecker.  Their presence indicates a healthy longleaf ecosystem.  However, due to loss of habitat, these birds are now rare and endangered.

A dozen or more species of frogs, toads, tree frogs, and salamanders can be common in pine flatwoods, especially those with more standing water.  Reptiles favor slightly drier habitats and these include black racers, rattlesnakes, skinks, lizards, and box turtles.  The ubiquitous gray squirrel of suburban backyards is not especially common in pine flatwoods, nor are fox squirrels.  Small mammals, such as mice, rats, and shrews occur, and are probably common, but are not frequently seen.  Bobcats and gray foxes are even less likely to be seen.  Of the large mammals, only white-tailed deer are wide spread in pine flatwoods.  Black bears, especially in Florida, are restricted to a few isolated pockets and panthers have been extirpated.

While longleaf pine is often associated with slash pines and pond pines in pine flatwoods ecosystems, in the other ecosystems where it occurs, longleaf is likely to be the only pine species.  This is the high pine of sandhills and clayhills.  While differing significantly, these upland habitats share some characteristics with flatwoods.   For instance, both ecosystems are dependent on fire.


In peninsular Florida, flatwoods often grade into sandhills.  Besides longleaf pines, many of the understory species are common to both.  Yet, overall,  the two ecosystems have very different looks to them.  While the flatwoods understory often abounds with thick saw palmetto and gallberry, the rolling hills and uplands of high pine are more open and park-like in appearance.  There the longleafs, frequently interspersed with turkey oaks, rise above a continuous cover of wiregrass and a diverse mixture of other herbaceous plants on deeper better-drained but less fertile soils.  On even deeper sandy soils, the sandhill ecosystem is replaced by scrub, another fire dependent community.  In the Big Scrub of Ocala National Forest, sandhills occur as “islands” in the scrub.  Elsewhere, the reverse -- islands of scrub among the pines -- is more frequent.

In the northern parts of the Florida panhandle, along the Cody scarp, sandhills give way to clayhills which are characterized by relatively more moist and fertile soils.  Variants of both sandhills and clayhills extend north from Florida to Virginia and west to Texas, making the high pine longleaf ecosystem once the most common forest type of the southeastern coastal plain.  Flatwoods are more common in Florida, but outside of the state are limited to low -lying coastal areas.

Fire is critical for maintenance of the longleaf component of the high pine community.  Frequent low-intensity fires must recur every one to ten years or hardwood trees, primarily oaks, will begin shading out the understory, preventing regeneration of longleafs.  The longer the intervals between fires, the more prevalent oaks become.  On account of extensive logging and fire suppression, turkey oaks rather than longleafs today dominate most sandhills.  On many clayhills, by the same token, post oak and blackjack oak now predominate, together with shortleaf and loblolly pines.  Other oaks associated with high pine are bluejack oak and sand live oak, with southern red oak and live oaks occurring in the more fertile soils.  Hardwoods, including persimmon, black cherry, and sassafras increase in abundance as fires become less frequent.  Mockernut hickory is an indicator of more fertile soils and flowering dogwoods often occur in the ecotone transition to hardwood hammock.

Early explorers and naturalists remarked upon the open nature of the upland longleaf forests.  Periodic fires kept shrubs from proliferating, but blackberry, blueberry, sumac, paw-paw, and gopher apple were common.  In addition to abundant wiregrass, there were many species in the ground cover, becoming increasingly rich in variety as one moved from xeric habitats to more mesic sites.  Colorful wildflowers included blazing star, summer farewell, silk-grass, greeneyes, partridge pea, and several asters.  Dog fennel, legumes, and bracken fern were often abundant.

Many of the animals found in pine flatwoods also occur in the high pine ecosystems.  Some birds which become more common in the open habitat, especially if there is a healthy herbaceous ground cover, include northern bobwhite quail and Bachman’s sparrow.  If there are large mature longleafs, usually over 100 years old, the endangered red-cockaded woodpecker may be present.  They nest in live trees, but dead trees or snags are used by most other cavity nesting birds; these include other woodpeckers, kestrels, bluebirds, great crested flycatchers, and screech owls.  Fox squirrels, sometimes found in pine flatwoods, are more often seen in high pine, but even here, due to loss of habitat, they are not common.

Perhaps the animal most typical of sandhills is the gopher tortoise.  In suitable habitat, gopher tortoise densities can be as high as two per acre.  That is uncommon, as for many years the tortoise was hunted for food and has been extirpated from many areas.  Gopher tortoises are important, for as many as 300 other animals use their 15-20 foot deep burrows.  These include snakes, frogs, foxes, spiders, and beetles.  Another burrowing animal found in this habitat is the southeastern pocket gopher, a mammal, but often called a “salamander,” a corruption of “sandy mounder.”  The name reflects the appearance of this animal’s burrow which is also used by other species.


Copyright 2010.