Three Leaves, One Tree - Tales From a Sassafras
Walking through the woods at Harmony Hill as summer begins to wane, we once again notice the hardwood trees. The knowledge that their leaves will begin falling in the coming weeks causes us to take in their beauty as we did in the spring. Though the summer days can be hot, muggy and long, we know that this season can be all too fleeting. And with a couple of cool mornings, Mother Nature has reminded us that we will be saying goodbye to these rather warm days before we know it. With the thought of falling leaves on our minds, we thought we’d take a look at a tree that many simply walk past and stop awhile to revel in its wonder and its complexity. Because, at Harmony Hill, we know common never has to mean simple!
Sassafras (Sassafras albidum) is a common tree throughout South Carolina and is, indeed, the Sassafras used in Sassafras Tea. Sassafras Tea is made by boiling the roots, which extracts both the color and the delicious flavor from the root bark.
Sassafras trees are extremely easy to identify, having three different leaf types growing on a tree. It is one of just a few species in our area that exhibits the ability to grow several different types (or shapes) of leaves. Perhaps we will spotlight another species of tree that does this in a future installment!
The first leaf is a single-lobed leaf that looks exactly like what everyone thinks a leaf looks like. In fact, if you gave a small child a crayon and asked it to draw a leaf, we'd be willing to bet it would look very much like the single-lobed Sassafras leaf.
The second leaf is a two-lobed "mitten" leaf. The name “mitten leaf” is rather fittings, as it looks exactly like a winter mitten, with the thumb sticking out of the larger mitten area.
The third leaf is a three-lobed leaf that is usually equal in size over all three lobes. (Occasionally, there may be a three-lobed leaf with a couple of extra lobes that are reduced in size and near the leaf stem. Depending upon the individual Sassafras tree, they may be anywhere from nonexistent to occurring with some regularity.)
Now, why would a tree grow three different and distinct types of leaves? Well, the answer may be found in WHERE the leaves are found on a tree. Often, the three and two-lobed leaves are found lower on the tree, while single-lobed leaves are found higher on the tree. This is even true on saplings, with the majority of the first leaves being three and two-lobed. It appears that early leaves grow in the presence of more nutrients and starches, which allow for more cell division; thus, allowing those leaves to "branch out" into more lobes. In fact, recalling what we said in the last paragraph, that may very well be the reason it isn’t horribly difficult to find the occasional four or five-lobed leaf mutation of a three-lobed leaf.
Sassafras is in the Laurel (Lauraceae) Family, along with Spicebush (Lindera benzoin). Both plants, along with a few other members of the family, are larval food hosts for the Spicebush Swallowtail Butterfly (Papilio troilus). One of the "Black Swallowtails", some of the finest beauty of this species of butterfly can be found in its larval stages.
Seen in the first and second photos, the caterpillar of the Spicebush Swallowtail looks a whole lot like bird droppings in its early instars. Feeding on leaves out in the wide open is a precarious way to make a living, so it pays to camouflage yourself as best you can. And what better camouflage than to look identical to bird droppings?
Now, another cool thing about this caterpillar is that it transitions in later instars to mimic a tiny snake (and some say, maybe, tree frogs). They will turn from the black and white camouflage of the fecal matter and uric acid of bird droppings to a yellowish caterpillar with late, false eyes. In fact, if you look at the larger end of the caterpillars in the photos, you can see those large black false eyes developing. This imperfect Batesian Mimicry allows the caterpillar to appear to be more than one species that predators don't wish to consume or bother with.
To take the mimicry one step further, as with all swallowtail caterpillars in North America, the Spicebush Swallowtail has a forked organ that emerges from just behind the head, called an osmeteria. They use this organ to deposit foul smelling and tasting chemicals onto potential predators. It also doesn't hurt that its forked and looks like the tongue of a snake!
These caterpillars will spin a silk mat below them, which is visible in both photos, in which they will anchor to. They will then use the silk to roll the leaves up around them as protection.
While Spicebush is its primary larval food source, it readily consumes the leaves of Sassafras. I've also seen it on Red Bay (Persea borbonia) and Swamp Bay (Persea palustris). Unfortunately, Red Bay and Sassafras have been impacted by a fungus introduced into the southeast, (Raffaelea lauricola). This fungus is transmitted by the Ambrosia Beetle (Xyleborus glabratus) and was first documented back in 2002.
Red Bay has suffered large mortalities from wilt brought about by the fungus and Sassafras has been impacted in many areas, as well. Spicebush has been found to also show signs of the disease. The death of these plants and trees has a direct impact on other populations, such as butterflies. The Spicebush Swallowtail is joined by the Palamedes Swallowtail (Papilio palamedes) in relying on members of the Laurel Family.
So, Harmony Hill isn't only a place we work to conserve and protect for beauty and peaceful nature. It is also land which is critical for butterfly species that are on the decline due to disease. Now, next time you're out walking in the woods, and you see rolled up leaves on a Sassafras, smile knowing that Spicebush Swallowtail caterpillars are eating and growing, and they will soon be taking to the air as adult butterflies!
Well, this Nature Note was a little more than we had originally planned. We looked at more than multiple species again, learned about leaf growth, a little about camouflage, mimicry AND we saw how introduced pests can cause serious issues on the landscape, like fungal diseases in native plants.
Nurse Logs: Renewal and Regrowth
Nature is an eternal teacher. Lessons in biology, psychology, mathematics, geology and even art can be found during each walk in the woods. When you look and listen, nature has much to teach. During one of our last walks along the trails of Harmony Hill, we got a lesson in the healthy renewal, regrowth and regeneration of the forest.
One of the main goals in how we approach the land is to find a balance in the habitats and ecosystems at Harmony Hill, in which the land can maintain a healthy state that allows the native flora and fauna to flourish with minimal management from human hands. There are spaces on the land that require a little more thought and effort to reach that level, but there are spaces that will be there earlier. We are always looking for places that can show us what Harmony Hill will be without the heavy hand of man on the landscape. We found that in something many people would walk right by, paying little attention.
We have often spoken about the sights and sounds of the forest, bringing life and energy to spring and summer days. However, death is as much a part of the forest as that liveliness. This is not a morbid fascination, but a fact of life. For every plant and animal that lives on the landscape, there will come a time when it ceases to live. The tall and stately trees that fill the forest grow to reach the sunlight and provide shelter, food and structure for myriad species. Throughout their lives, the large trees we love to see as we walk the trails will be nesting sites for birds and squirrels, give vines natural ladders to climb, grant shade tolerant wildflowers a much-needed respite from the hot summer sun, as well as become part of a larger subterranean community through their extensive root systems.
An unclose look at a hole previously drilled by a Northern Flicker that is now a planter for a Loblolly Pine sapling. Photo courtesy Lisa Riente
When these same trees die, they don’t stop giving to the land. Quite the opposite, in fact. They continue to nourish and provide for fungi, insects, birds, reptiles, mammals and, most importantly, their fellow plant life at Harmony Hill. Rounding the corner of on one of our walks, we witnessed exactly that and it allows us to share the story of nurse logs, their importance to forests and how they fit into the well-oiled machine that is Mother Nature.
When a tree dies, whether it still stands in the woodland or if it dies from being uprooted by the wind, it begins to decay. As the wood fibers break down, fungi and bacteria start the work of returning the tree to the forest. Insects quickly move in to help consume and recycle the rotting tree and the fungi. As those insects arrive and increase in numbers, birds, reptiles and mammals come on the scene to take advantage of the bountiful prey items. The tree, once alive and growing, comes to life in an entirely different way. This time, the tree serves as a condominium and buffet for everything from microscopic bacteria to large Pileated Woodpeckers in search of beetle larvae. For many reasons, most woodpecker species thrive on dead wood. At Harmony Hill, we host Downy Woodpeckers, Hairy Woodpeckers, Red-headed Woodpeckers, Red-bellied Woodpeckers, Yellow-bellied Sapsuckers, Northern Flickers and Pileated Woodpeckers all, or at least a portion, of the year. Just as important as the decaying wood, these woodpeckers are an integral part of this story. Their engineering and excavating are clear in the photos, and the impact they have on the creation of new forests is obvious.
One of the insects that will utilize moist, decaying wood Is the Carpenter Ant (Camponotus pennsylvanicus). Both standing snags, also referred to as standing course woody debris, and fallen logs, referred to as downed course woody debris, see Carpenter Ants move in. One of our year-round woodpecker species, the Northern Flicker (Colaptes auratus) is a wonderful consumer of ants. They even actively forage for and eat the red imported Fire Ant (Solenopsis invicta). When Carpenter Ants move into snags at Harmony Hill, we often see Northern Flickers pecking and chiseling away wood to get to ants and their larvae. Even as a snag stands rotting above the forest floor at Harmony Hill, the makings of the next forest are taking shape. And the Northern Flicker is part of building what is to come for generations in the woods of Harmony Hill.
If a dead tree isn’t felled immediately by the wind, when it does eventually fall, it takes the final steps in returning to the forest and feeding the future. The journey from living giant to nurse log closes and each bacteria, fungi, insect, bird, reptile and mammal interaction shows purpose towards the balance we seek. The presence of the Carpenter Ants, initially seen as just an insect feeding on rotting wood, and a Northern Flicker making holes in the tree to find those ants, becomes critical to a new Loblolly Pine (Pinus taeda) sprouting to fill an empty place. The nurse log, now lying on the ground, begins to host other species, such as a perched Gray Squirrel (Sciurus carolinensis) working a pinecone like corn on the cob, searching for pine seeds to feed on. Rainfall now fills the holes drilled by the woodpeckers, as do leaves and dust, causing the wood to further decay. Those holes, as is plainly seen in the photos, become their own micro ecosystems, allowing seeds that have been dropped by squirrels and even other trees to arise from the tiny places hosting soil creation.
Nurse logs are natural mulch sites, holding water and delivering nutrients as they decompose. As animal traffic increases and more fungi, mycorrhizae and roots systems interlace throughout the carcass of the tree, more of the wood is broken down and more places become active hosts for more plants and trees to sprout. Even with many years of decomposition, the nurse logs are giving themselves back to the ground from which they grew. And with each stage of decay, the nurse log falls flatter to the forest floor and the cells of the tree slowly but surely become organic material for the soil below. Roots of Red Maple (Acer rubrum), Loblolly Pine and other trees stretch down into the earth and are fed by their rotting relative.
Death is not the end. It is merely a transition from one form to another. These nurse logs show us there is energy left to return to the earth and that there is still much left to give back to the environment that fed you. Life doesn’t truly end when cells cease splitting. And each inhabitant of the forests of Harmony Hill are a crucial part of the wooded areas of many years from now. There is no coincidence in the decomposition process of creating a nurse log. We see the value of each mushroom and critter that builds rich soil by simply living out their life cycle in and around a tree which dies on the landscape.
Just as “the butterfly effect” illustrates the potential for the flapping of a butterfly’s wings could impact the formation of weather patterns, we see the drumming of a woodpecker’s beak impacting the formation of tomorrow’s forests. Nature is an eternal teacher. When you look and listen, nature has much to teach. May we always be open to learn her lessons.
Soapy, Sappy Pine Tree
On Valentine’s Day, Sunshine sent a photo of foam at the base of a pine tree. Along with the photo, she asked a very logical question… “What is this and what caused it?” (See photo accompanying today’s post to see the bubbles in question)
It is a conundrum. A foamy, sudsy froth coming from a pine tree is an odd thing to find while out on a walk in the forest. In fact, it isn’t something many people I know have seen; even those who have spent a lot of time working, playing or walking in the piney woods. As has become the case with our discussions here, we’re going to look deeper into the science behind the mystery. What would cause this to occur at the base of a pine tree?
When I saw the photo, one of the first things I knew immediately was that there had been a great deal of rain there for an extended period of time. The reaction that occurs to make the observed foam is an extremely simple type of weak saponification, or soap-making. And this reaction only occurs during times of abundant rain.
What does rain have to do with it? The extra moisture reacts with chemicals in the pine resin, as well as chemicals in the air, to create soap-like suds. Some of the same chemicals in pine resin that contribute to the old recipes for pine tar soap are at play here. Along with phosphates and other chemicals in the air that find themselves trapped in the layers of bark on the tree, the rain (in both the form that falls on the tree and the water that has been taken up by the tree) reacts to make the bubbles.
Why does this almost always occur at (or near) the base of pine trees? That’s an easy one… Gravity! As the rain on the outside of the tree trickles and runs down the trunk of the tree, weaving its way through the bark and along the crevices of the tree, it helps froth the simple soapy substance. And, as you’d expect, this occurs more prominently as it picks up momentum and nears the base of the tree.
The joys of a rainy day walk in the woods bring far more than just tranquility on a quiet day in nature. Those walks also bring observations that pique our curiosity and opportunities to learn what causes things rarely seen in the forest. Like, the mystery of the bubbly bark! (or, the percolating pine… or, the sudsy sap… I’ll see myself out, now!) 😂