Longleaf Pine

Longleaf pine

Longleaf Pine is an iconic tree of the southeastern coastal plains, much as the Redwood and Sequoia trees dominate their respective regions of the West. It is hard to get a sense of the Longleaf Pine’s historical ecologic and economic importance as one passes through the fields, pine plantations, and forests of the southeast today, as it is eerily absent from most of its former habitat. Longleaf once covered 90 million acres with a range stretching from southeastern Virginia to south Florida and west to Eastern Texas. Longleaf Pine forests are estimated to cover only 2% of the land they formerly grew in, a sobering loss that many ecologists rank among one of the largest ecosystem declines worldwide.

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Where did it all go? The first European people brought their livestock and set them free in the forests to forage. Hogs are especially hard on pines, eating the roots and leaves, but also disturbing the ground with their rooting, upending tender saplings in their wake. After the larger threats of habitat fragmentation and fire suppression, feral hogs still remain a detriment to the health of the remaining longleaf forests.

The trees were tapped and cut to produce pitch, tar, and turpentine for caulking ships and waterproofing canvas sails.  The southeastern Longleaf Pine forests were responsible for producing 70% of the world’s supply of naval stores (pitch, tar, and turpentine) in the early twentieth century. Finally, the large expanse of old growth Longleaf Pine was cut for its lumber around the same time. Its forests were replanted with faster growing species of pines for the pulp industry, and their habitat largely replaced with fields for cows, roads, cities, agriculture, etc. For more on longleaf history.

Characteristic silver terminal bud of longleaf

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Longleaf Pine is quite an adaptable tree, growing in wetlands and dry sandy soil alike. Its scientific name is Pinus palustris:  palustris, derives from Latin, signifying marshy or swampy. Many people erroneously believe that Longleaf Pine only grows in the dry sandhills; it is often confined to these poorer soils because the land with richer or moister soil has been appropriated for agriculture or development. Longleaf Pine is considered a keystone species with hundreds of species of animals and plants dependant on its health, such as the gopher tortoise and red-cockaded woodpecker. Longleaf plant communities are especially diverse, with an understory of plants especially adapted to frequent fires and nutrient-poor, dry soil. The plant diversity in the understory of Longleaf Pine savannahs is staggering; when biologists count plant species per square meter, the Longleaf Pine ecosystems are among some of the most diverse in North America– 95 plant species per 100 square meters.

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Many Longleaf Pine communities historically experienced frequent fires, typically every two to five years, and in some instances annual fires were commonplace. In areas where frequent fires burn up the fallen wood and flammables the fires are less intense and tend to remain ground fires, rather than catastrophic raging fire rising to the canopy (as found in forests that use fire suppression). In addition to the common lightening storm-generated fires of spring and summer, Native people actively set fires to clear agricultural areas, increase browsing for game, and keep tick and chigger populations down. Fire suppression is one of the biggest challenges to the fire-adapted communities of the southeast. Many plants need fire to release seeds or to germinate, and many fire-adapted plants are quickly replaced with faster growing plants when fire is suppressed. People have been putting out forest fires to protect human communities and activities, and only in the past few decades has there been increased public awareness of the role of fire in healthy southeastern forests.

Longleaf Pine forests are not just fire adapted, they actually need fires to flourish and persist. If fire is suppressed, other faster growing species of pine will begin to dominate. Over time evergreen hardwood trees begin to creep in as well, shading out the understory and ultimately preventing longleaf seedlings from reaching the canopy. Fire clears out the understory and allows the Longleaf Pine seeds to fall unimpeded to the forest floor, with the sunlight and open ground necessary for germination. Longleaf Pines release their seeds in the fall, when the danger of fire is the lowest. After they germinate it is a race against time to grow large enough to survive a ground fire. While other pines invest energy in quick upward growth, longleaf has a more complex, slower strategy, evolved over millennia in response to the frequent fires of the southeast. Young longleaf saplings hug the ground in a tight cluster of needles, foregoing aerial growth for the development of a deep taproot, which often reaches 8 feet deep in less than a year. This low pattern of growth is called the grass stage, as the young sapling does indeed resemble a clump of wiregrass in the first part of its life. The grass stage typically lasts two to five years (up to 12 years); during this time the tree is garnering resources in its long taproot and accessing groundwater, which is a rare resource in the land of porous sandy soil.

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If a fire blows through when a tree is in the grass stage, its tight needles are able to protect the growing terminal bud from permanent damage; even if the needles are scorched, the bud is able to produce a new generation of fresh green growth. After the tree has grown a sufficient taproot, it sprouts quickly in one season, above the danger of a low ground fire. It then begins to invest energy in the thick insulating bark typical of pines, which will continue to protect it from fire’s harm for hundreds of years.

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This important tree, with its unique ecology, has become a priority for many land management agencies and private landowners. Prescribed burning (planned intentional fire) is fanning the health of these ancient forests. The presence of federally endangered animals, such as the red-cockaded woodpecker, is also giving the forests some protection. Its largest threat is the burgeoning human population of the southeast with its industries of pulp, cows, agriculture, etc. As the public gains a greater understanding of the natural history of the longleaf forests, we can hope to see its resurgence through increased planting and prescribed burning. It is a joy to lie under the dappled shade of longleaf pine on a soft bed of fallen bronze needles, gazing up at the swaying green canopy interspersed with bright blue sky, and lulled by the swishing sound of the wind playing in the treetops. It is my dream that these forests keep getting bigger, with the trees living to a ripe old age, dying from causes that have nothing to do with humans.

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If you are interested in learning more about this fascinating tree, I recommend the book Looking for Longleaf by Lawrence Earley. Following is a poetic excerpt from the book: “The land of the longleaf pine is a land of great beauty but also of great violence, born from an encroaching sea and shaped by rivers, storm, and fire. It carries the evidence of immensities of time spent beneath ocean waters; the shells of sea creatures lie thick in the soil. Past seas shaped this land’s terrain, rivers its very pitch and roll. It’s a green land, year also a land of flame and ash. It was this region of sand and sea, wind and fire that longleaf flourished as no other pine could do, perfectly adapted to the conditions, swaggering over the Coastal Plain from southeastern Virginia to eastern Texas.”

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