Longleaf pines, which may exist in the grass stage "up to 10 years," have survival strategies tested under fire


Excerpt from "After the Fire: Longleafs and New Growth"


“The pine’s new year begins in May, when the terminal bud becomes ‘the candle,’” wrote Aldo Leopold. “Whoever coined that name for the new growth had subtlety in his soul. ‘The candle’ sounds like a platitudinous reference to obvious facts: the new shoot is waxy, upright, brittle. But he who lives with pines knows that candle has a deeper meaning, for at its tip burns the eternal flame that lights a path into the future. May after May my pines follow their candles skyward, each headed straight for the zenith . . .”

To study the adaptation of longleaf-wire grass forests to fire, I went in late May to a woods in the Carolina Sandhills NWR with Forester Clay Ware. This threatened ecosystem needs periodic low-intensity fires to fend off hardwood encroachment. Early in May and “well into the growing season,” said Clay, the NWR crew had staged one of the last burns of the year to preserve a portion of this ecosystem.

Dead, fire-scarred leaves dangled from blackened branches of five- to eight-foot scrub oaks. Last fall, Clay explained, the oaks had stored nutrients in their roots for the next growing season. “This spring, those nutrients were allocated to leaf production. By the time of the burn, the oaks--which we’re trying to get rid of--had already leafed out. When you burn this time of year and kill the scrub oaks’ leaves, you really put the hurt on them. They have limited nutrients stored in the root system to produce new leaves” . . .

The ground we stood on was still black and charred. At first glance, the only color I noticed was a sprinkling of orange longleaf needles. “Needle cast,” said Clay. I was surprised by the length of the needles--up to 18 inches. More heat-singed needles hung from the lower branches of more mature pines, which were often 50 feet tall and 12 inches or more in diameter . . .

I surveyed the black forest floor and for the first time noticed hundreds of grass-stage pines festooning the ground. Although each was charred, each boasted a spray of little green needles. “You can see all of this new growth right above the needle scorch,” he said.

I was impressed and asked if most of the grass-stage longleafs had survived the fire. “Oh yeah,” said Clay. At this stage, their terminal buds are small, hard, and fire-resistant. Even if a fire kills the bud, at the root collar there's a latent bud which steps up, enabling the seedling to survive.