What Time is it in Nature: Longleaf Pine
The first day of spring has arrived, and with it comes several more signs of spring! One good sign is visible on a tree with an interesting biology that has played a prominent role in North Carolina’s history, the Longleaf Pine (Pinus palustris).
Longleaf Pine is a pine species native to the southeastern US. The trees grow tall and straight, reaching heights of over 100 feet at maturity. The leaves are dark green and needle-like and grow in bundles of three. The needles are, as the name suggests, quite long, reaching lengths of over 17 inches. Longleaf Pine also has thick bark, which is important to its biology.
Longleaf Pine undergoes a fascinating reproduction and growth process. The trees produce two types of cones, the pollen-bearing male cones and the seed-bearing female cones. Both types of cones are first produced in summer, then grow slowly over the fall and winter before becoming active the following spring. The purple male cones will release pollen:
… to fertilize the female cones:
Fertilized female cones then continue to develop over another year and a half before releasing the seeds. A female cone may eventually reach lengths of nearly 10 inches by the time the seeds are released.
Longleaf Pine seeds need open, sunny patches of ground to germinate. If they are dropped in the right location, the trees develop slowly over several years in what is called the grass stage, developing an extensive root system while remaining very short and brushy above ground. Eventually the trees experience an amazing growth spurt and grow up to 10 feet a year for several years before reaching their full height. Branching begins once the trees reach at least 10 feet tall, and new needles emerge from white buds, often called candles and visible in the image above, in the spring once branching begins.
Longleaf Pines are adapted to experience periodic, low intensity fires and such fires are necessary for Longleaf forest health. The trees need a lot of light and have thick, fire resistant bark, so fires help keep Longleaf forests open by burning off shade-producing plants and shrubs. The seeds are also unable to penetrate dense leaf litter to reach the ground, so removal of the ground cover by fire promotes germination while the ash provides valuable soil nutrients. Though it is counterintuitive, fire suppression is one of the worst things you can do to a Longleaf Pine forest and this practice has contributed to the destruction of the ecosystem. Over the past few decades, controlled burn programs have become an important management tool for the maintenance and restoration of Longleaf Pine forests in the southeastern US.
Now commonly considered the state tree (though technically the state tree is simply “pine”), the Longleaf Pine has played an important role in North Carolina’s history. From the early days of colonization, the Longleaf Pine forests of North Carolina have been harvested for timber, but they also supported a strong “naval stores” industry. Tar, pitch, turpentine, and rosin are all products of pine, and the vast Longleaf Pine forests of North Carolina provided these essentials to merchant and naval ships. Unfortunately, overproduction of these products and overharvesting of timber have contributed to massive reductions in the size of our Longleaf Pine forests. Throughout the southeastern US, Longleaf Pine has been reduced to about 3% of its historic acreage.
Prairie Ridge has only a few Longleaf Pines as we are outside of the current natural range of the trees in our state, but they are featured in our native tree arboretum. The male cones are currently vibrant purple and will soon release their pollen, and you can see growing female cones and brand new needles poking out of the candle-shaped buds. Be sure to visit the Longleaf Pines the next time you visit Prairie Ridge and take a good look at one of the best symbols of our great state!
What Time is it in Nature is a weekly feature highlighting the current plants, animals, and other wildlife at the Musuem’s public outdoor facility, Prairie Ridge Ecostation. Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive!
(Photos by Chris Goforth)