Green Shelters

The distinctive roar of the longleaf was the sound the evening breeze made, and the odor of pine resin was the smell of the countryside…It was so much a part of their lives, so wound up with everything it meant to be southern, that it was as impossible to discern its influence as it was to imagine a world without it. Only when it was reduced, almost entirely, to a sea of stumps could we begin to get our arms around it.

~~Bill Finch in Longleaf, Far as the Eye Can See

These past few weeks have flown by with so much happening both at work and home. Highlights have included a couple of trips to a region of North Carolina that is quickly becoming a favorite, and is home to extensive longleaf pine savannas and their associated diversity of plants. The place is southeastern North Carolina, and the destinations are the Green Swamp Preserve and Holly Shelter Game Lands. One trip was with some of our trained volunteers from the NC Botanical Garden. The other was an educator trek highlighting the carnivorous plants of the region. Both were in collaboration with the NC Museum of Natural Sciences. Compared to our home here in the Piedmont, this land of longleaf really is a different world in the way it looks, feels, and sounds.Here are a few highlights from those trips (spoiler alert…more to come in future posts)…

Longleaf pine savanna

Longleaf pine and wiregrass along a road in Holly Shelter Game Lands (click photos to enlarge)

The classic longleaf savanna has a dense understory of wiregrass and a host of other herbaceous species under a canopy of tall longleaf pines. Variations of this conifer-dominated community once covered 90 million acres along the Atlantic and Gulf Coasts. Logging, the naval stores industry, land conversion, and fire suppression have reduced this once dominant plant community by 97%. Land managers are working to restore this treasure by using a tool that helped shape this diverse landscape – fire.

Grass stage of longleaf pine

Grass stage of longleaf pine following a prescribed burn

Scientists estimate natural lightning-caused fires once occurred on average every 3 to 7 years in much of the Coastal Plain. Years of fire suppression shifted the balance in plant communities to favor more deciduous species like turkey oaks at the expense of longleaf pines and the associated savanna species. Regular burns are helping turn this around, allowing the fire-adapted species to once again thrive. At both sites, we saw evidence of the adaptability of the many growth stages of longleaf to the effects of fire (see Melissa’s post from last year on longleaf). Plenty of singed needles, but the majority of growth tips survived, helping create a patchwork of green in the charred landscape.

Bottlebrush stage of longleaf after fire

Bottlebrsush stage after a fire

Looking down on growing tip of bottlebrush stage of longleaf aft

Growth tip of a longleaf pine in the bottlebrush stage

Bring the plants back and you start to bring back the animals as well.

Red-cockaded woodpecker nest cavity

Red-cockaded woodpecker nest cavity surrounded by sap flow

The federally endangered red-cockaded woodpecker depends on mature longleaf pine forests for its nesting cavities. They are the only woodpecker that regularly excavates cavities in living trees. As such, they are considered a ‘keystone’ species, because use of their cavities (either for roosting or nesting) by at least 27 other species of vertebrates contributes to the species richness of the pine forest. We saw numerous cavity trees scattered about the savannas. Most are marked in two ways – one human, one avian. Researchers monitoring the birds’ population regularly mark nest trees with two bands of white paint around the trunk of the tree. The birds drill numerous holes above and below the nest entrance, creating a sap flow that dries a whitish color and is visible at considerable distances. The sap is believed to help reduce the threat to eggs and nestlings from predators such as rat snakes.

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Dwarf azalea in pine savanna

Flower buds of dwarf azalea

Dwarf azalea flower buds

Dwarf azalea

Dwarf azalea blossom

At our last stop in Holly Shelter, we enjoyed the beauty and fragrance of dwarf azaleas, Rhododendron atlanticum. This low-growing shrub makes an eye-popping display in the sea of wiregrass. A closer look revealed some other striking flowers under the pines.

Iris verna

Dwarf iris, Iris verna, in the Green Swamp

grass pink orchid flower

Grass pink orchid

The pine savannas are known for their unusual plants, including a host of native orchids. Early in the season, the grass pink orchids, Calopogon sp., dominate. The genus name is Greek for “beautiful beard”, referring to the cluster of yellowish hairs on the upper lip of the flower. This flower produces no nectar, but the bushy hairs resemble the pollen-bearing anthers of other flowers, thus fooling insects to land for a snack.

grass pink orchid flower showing hinged upper lip

What happens when a bee lands on the fake anthers of a grass pink orchid flower

The upper lip of the orchid is hinged at the base. When an insect lands on it, the lip drops, flopping the insect onto the reproductive parts of the flower (called a column) hopefully leading to pollination. In the photo above, the twig pushing down on the lip shows what happens when an insect, such as a bumblebee, lands on the yellow hairs – it is dropped down onto the column.

Fly on meadow beauty seed vessels

Fly resting on old seed pod of meadow beauty

We also saw a lot of other insects in the savanna including many Palamedes swallowtail butterflies. And where there are insects, there will be spiders, waiting…

Crab spider on flower

Crab spider awaiting its next meal

wolf spider with babies

Wolf spider with babies and egg sac

This mother wolf spider is carrying her egg sac on the tip of her abdomen while the spiderlings hatch and crawl onto her back. They will cling to her for a few days until their first molt.

wolf spider with babies close up

Hitching a ride with mom

Our savanna time was well spent and we all came away with a new appreciation of the magic of this habitat. The gentle roar of the wind in the pines is definitely a soothing sound.

Longleaf pines and sunlight

Longleaf pine canopy in the Green Swamp Preserve

And, if you take the time to stoop down and look closely, there are many marvels to see…

looking at flytraps

What are they looking at?

Stay tuned…

 

 

Longleaf Lost

The power of the ocean
in what does it lie?
In the endless, timeless roar of the surf?
In the immense vistas – the view to the end of the world?
In the glowing spray as it diffuses
the light of the rising sun?
In the power and mystery of its
dark depths?

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No matter—
it brings one to scale
it breathes into one serenity
it insists that one pause…

Once—
was the world filled with
such wild landscapes?
With these tests and salves for the
human spirit?
Before we spent what we did not own?

Were the monarchs of the southeastern forest
as the ocean?
The longleaf pines—
In their endless and timeless ranks
With their immense vistas—
views of waving grasses
as far as the eye could see?
In the power and mystery of their length and breadth?

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Would one have found scale? Serenity?
Would one have been impelled to pause?

Do we mourn for what we have not known
but by glimpses
through another lens?

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Grass, Bottlebrush, Candelabra, Pine?

Here’s to the land of the longleaf pine,
The summer land where the sun doth shine,
Where the weak grow strong and the strong grow great,
Here’s to “Down Home,” the Old North State.

~North Carolina State Toast

In my last post, I talked about some of the amazing, small plants that grow beneath the longleaf, but not so much about the longleaf itself. It, too, is well-adapted for poor, sandy soils and thrives in an environment frequently visited by fire, and has some amazing strategies for surviving under those conditions.

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Stand of longleaf in Croatan National Forest; the tall golden grasses are wiregrass which has seeded after a fire (click photos to enlarge).

Longleaf are not tolerant of shady conditions. In a mature savanna, they grow spaced fairly far apart so that each needle on each branch can receive as much sunlight as possible. They lose their lower limbs as they grow larger, and viewed from the ground seem to provide a loose, permeable canopy held aloft by elegantly arranged poles. This openness is one of the reasons that the savanna has such a diversity of low-growing species. The other is fire. Fire clears away other shrubs and trees, like turkey oak and gallberry, that typically grow beneath longleaf pine, and opens the forest floor for shorter species, like carnivorous plants, as well as seedling longleaf. Mature longleaf trees have thick bark that makes them resistant to all but the hottest fires. But with fire occurring every 3 years or so, historically, how would that allow new longleaf to sprout? Well, their growing stages are also perfectly adapted to this sandy, fire-prone habitat.

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Recently burned longleaf stand in Croatan National Forest

A longleaf seed is most likely to be successful if it germinates in a relatively open area where it receives a lot of sunlight… which is just what you would find in a longleaf savanna just after a fire. The seedling develops into a special phase of life, unique to longleaf, called a grass stage. At this stage, the “tree” is just a tuft of needles at ground level that looks very much like the surrounding wiregrass. For a period of around 3 years (sometimes shorter, but sometimes much longer), the longleaf grows downward rather than upward, sending a taproot deep into the soil to fuel future growth. During this stage, it is, perhaps surprisingly, fairly fire resistant. The thick needles protect the all-important growing tip at the heart of the grass stage. Even if the needles are mostly burned, the tree can still make it!

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Grass stage longleaf trying to blend in with the surrounding wiregrass

When the time is right, the longleaf moves out of the grass stage with rapid vertical growth. It develops a thick, white bud-like tip, sometimes called a candle, and from there begins its growth.

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The growing tip or “candle” of a longleaf

Its goal during this time is to get tall enough and develop thick enough bark to survive a fire. This is no time to worry about branches, so the young tree looks much more like a bottlebrush than anything else; this stage is often called the “bottlebrush stage.” Though an educator on a workshop once suggested that it should be named the “truffula stage” after the crazy-looking multi-colored trees in Dr. Seuss’ The Lorax. During this phase the young longleaf is most susceptible to fire.

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Bottlebrush longleaf striving to grow as tall as its neighbors

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Bottlebrush longleaf after a fire – notice that it is still green around the growing tip!

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A group of young longleaf burned in a recent fire. Many still have green needles visible in the center.

But a tree just can’t grow up, and eventually the longleaf begins to grow out as well. The graceful side branches reach out horizontally and then turn up toward the sky. The “candelabra” stage is well-named! Longleaf tend to grow their 8-18″ long needles in clusters near the ends of branches, adding to the visual appeal of the tree.

At about 25-30 years, longleaf reach maturity and start producing cones. Though the species is fire-adapted, it does not have serotinous cones – cones that open in the heat of fire. A neighbor to the longleaf, the pond pine, which commonly grows in boggy pocosins adjacent to longleaf savanna, does have serotinous cones. My coworker Megan decided we needed to observe this phenomena for ourselves; so, armed with a lighter and a closed pond pine cone, we did! With the heat from the lighter, the scales of the cone opened with an audible pop, kind of like the popping of popcorn. Inside each scale were two winged seeds, as with other pines. Pond pines also grow best after fire, so their serontinous cones are a great adaptation to promote growth when the conditions are right. Longleaf don’t use that strategy even though they depend on similar conditions for germination. But their cones are equally impressive. The largest pine cones in North Carolina, they can be up to about 12″ long!

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Pond pine cone, opened after a fire

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Longleaf cone with my size 9 (men’s 7) rubber boot for scale

The oldest documented longleaf in North Carolina is found in Weymouth Woods State Park and is more than 465 years old! Though perhaps at one time there were many such old monarchs of the forest, that’s rare now. But mature longleaf play a very important role in the ecosystem, particularly for red-cockaded woodpeckers. As longleaf age, they become more susceptible to red heart fungus, which softens the (very hard) heartwood of the tree. Red-cockaded woodpeckers are our only species of woodpecker that seek out live trees for nesting, and they prefer mature longleaf pine that are infected with red heart fungus. This is because they hollow out nest cavities in the living trees, and the softening due to red heart makes that easier. They also peck holes in the tree surrounding their cavity that draw out the tree’s sticky resin. This acts as a defense against a common predator, rat snakes. If you’re visiting a longleaf forest and spot trees painted with white rings, look up for the cavity! Biologists studying RCWs mark their nest trees in this way to make them more visible.

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RCW cavity – this one doesn’t have extensive resin wells drilled around it.

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The distinctive white band of an RCW cavity tree. I like to joke about the endangered woodpeckers who fly around with a paintbrush in their little feet to mark their homes so they can fine them again later…

The longleaf pine savanna is an amazing diverse habitat, and the longleaf pine is well-adapted to live there. If you have the chance to visit, see if you can spot each stage of its life – grass, bottlebrush, candelabra, and mature tree!

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Graceful, mature longleaf