Wednesday, January 10, 2018

Longleaf Pines Forests and Red-Cockaded Woodpeckers

Longleaf Pine Forest

Let me throw some statistics at you. Prior to the European colonization of the United States, there was an estimated 90,000,000 acres of Longleaf Pine forest in the southeastern US. This Longleaf Pine forest ecosystem covered most of the Atlantic Coastal Plain from Virginia to Texas. Nowadays, of those 90 million acres, only 3,400,000 remain. That's only a whopping 4% of what it used to be. Of those 3.4 million remaining acres, only approximately 12,000 acres can be considered old growth Longleaf Pine forests. That's a mere 0.4% of the remaining 4%.

North Carolina Longleaf Coalition
Map of the Longleaf Pine forest historical range. Map courtesy of the North Carolina Longleaf Coalition.

As one might guess, the nearly wholesale destruction of the Longleaf Pine forest ecosystem had an incredibly negative impact on many of the animals which called this ecosystem home. Although some of the animals that lived in Longleaf Pine forests also lived in other ecosystems—say, for example, White-Tailed Deer and the Common Raccoon—many others were dependent on this ecosystem. And as the ecosystem became endangered, so did many of the animal species that were intrinsically tied to the ecosystem. Such animals include the Gopher Tortoise, Indigo Snake, and—most famously—the Red-Cockaded Woodpecker.

Santee Coastal Reserve Wildlife Management Area

Back in October of 2017, I ventured to the Santee Coastal Reserve Wildlife Management Area in Charleston County, South Carolina. This 24,000-acre wildlife management area (WMA) contains an assortment of different habitats, including salt marshes, freshwater swamps, barrier islands, and an extensive old growth Longleaf Pine forest. The Santee Coastal Reserve WMA was officially established in 1974, but the forest is much older. Prior to the acquisition of the land by the state of South Carolina, the forest and surrounding lands were privately owned. For the majority of the 1900’s, the land belonged to a hunting club, which managed the land for various game species, especially waterfowl. The natural stand of Longleaf Pine forest pictured above was essentially left alone, and it is now well over 100 years old. Presently, visitors to the Santee Coastal Reserve can drive the dirt roads that wind through the Longleaf Pine forest, hike along old rice plantation dykes that crisscross a salt marsh, or meander down a boardwalk that snakes its way into a Bald-Cypress swamp.

Longleaf Pine needle length
A 16-inch long needle.

Before we talk about the Red-Cockaded Woodpeckers that call Santee Coastal Reserve home, let's talk about the Longleaf Pine forest. As the name suggests, a Longleaf Pine forest is a forest in which the dominant tree is the Longleaf Pine (Pinus palustris). The Longleaf Pine is named as such due to the incredible length of its needles, which can reach up to almost 18 inches!

Longleaf Pine grass stage

The Longleaf Pine doesn't grow like a "typical" tree. When you think about the life cycle of a typical tree—say a White Oak or Sweetgum—the seed will sprout a sapling. That sapling will look like a miniature version of the adult tree—with fewer leaves and the like. That sapling will then grow in both girth and height, and more branches and leaves will be added. But Longleaf Pines go about growing a bit differently. When a seed sprouts, the resulting individual doesn't look like a tiny tree, but instead looks something more akin to a sedge or clump of grass. In fact, this part of the Longleaf Pine's life is called the "grass stage," and the individual pictured above is one such example. Longleaf Pines will stay in this grass stage for 1 to 12 years. During this period, they really don't grow upward. They instead focus on growing an extensive root system.

Longleaf Pine bottlebrush stage

After the grass stage, the individual will quickly shoot up a few feet, but will still not grow any branches. This stage is called the bottlebrush stage, and the individual pictured above is in this stage. After a few more years in this stage, the individual will begin growing taller and will finally start growing branches. Only at this point will the individual be considered a sapling.

Longleaf Pine pinecone

Around the age of 30 or so, the tree will begin producing pine cones, which are huge compared to most of the pine cones this Ohioan is used to seeing. Earlier I mentioned how the Longleaf Pine forest ecosystem nearly all but disappeared from the landscape. There are two main reasons for this. First and foremost, many a Longleaf Pine found its fate in the form of an axe or saw in the 1700's and 1800's. The Longleaf Pine can grow upward of 150 feet tall, and nearly 4 feet in diameter, making it especially attractive to the early American logging industry. An unbelievable number of Longleaf Pine stands were clearcut, and instead of replanting these stands with more Longleaf Pines, loggers and landowners mostly replanted the land with Loblolly Pines, which grow much faster. This faster growing rate meant a faster turnaround in profits for loggers. Most of the forests which were once dominated by Longleaf Pines are now dominated by Loblolly Pines, and those forests will remain that way unless someone steps in and properly manages the forest.

Longleaf Pine forest fire

The second reason for the decline and destruction of Longleaf Pine forests lies in the cultural push for fire suppression. Forest fires are a natural feature in nearly all the forests types throughout the US, although they vary in the rate of incidence. Some forest types, such as the eastern deciduous forest ecosystem, will experience a forest fire every 100-400 years on average. Other types of forests experience natural forest fires very often; the Longleaf Pine forest ecosystem historically experienced natural forest fires every 2 to 3 years. These natural wild fires were started by lightning, but—as I discussed in my previous post about the I'OnSwamp—Native Americans and even early European colonists exacerbated this natural rate by utilizing forest fires as a tool for altering the landscape. However, by the late 1800's and early 1900's, a cultural shift occurred in the US. Forest fires of any type, whether natural or set by humans, were considered dangerous and unnatural. Forest fires were suppressed as best they could be, and a bear dressed in human clothes hammered into the impressionable minds of American children that only they could prevent forest fires.

The problem is, most forested ecosystems are meant to burn in some form or another. The Longleaf Pine forest ecosystem must burn for its existence to continue. If all fires are suppressed, the plants in the undergrowth of a Longleaf Pine forest will begin to grow up, and eventually other tree species will crowd out and ultimately replace the Longleaf Pines. As it turns out, Longleaf Pine trees are nearly fire resistant, whereas other plants in this region are not as resistant to fire. In a Longleaf Pine forest's natural state, with fires occurring every 2-3 years, the Longleaf Pines will remain strong and healthy while other bushes and trees are repeatedly burned back. The Longleaf Pine can only maintain its grip in this ecosystem with fire being a common occurrence. Thankfully, we have come to realize that forest fires are a necessary component in many ecosystems, and many of the remaining Longleaf Pine forests are actively managed with low-intensity prescribed burns every few years.

Red-Cockaded Woodpecker and Longleaf Pine Forests

The quality of a given Longleaf Pine forest is of utmost importance for many of the animals and plants which call it home. Take, for example, the Red-Cockaded Woodpecker. The Red-Cockaded Woodpecker is a Federally Endangered species, and there are only an estimated 15,000 individuals left in the world. The disappearance of this species is tied directly to the disappearance of the Longleaf Pine forest from across the southeastern US. The Red-Cockaded Woodpecker relies almost exclusively on the Longleaf Pine nesting. And not any Longleaf Pine will do; no, the Red-Cockaded Woodpecker needs relatively old Longleaf Pines. When Longleaf Pines reach about 60 or so years old, a fungus will often infect the tree and cause Red Heart Rot. With this fungal disease, the heartwood of the Longleaf Pine will soften. Only in the softened heartwood of an infected Longleaf Pine tree can a Red-Cockaded Woodpecker build its nesting cavity, as it is otherwise too hard for the woodpecker to carve.

Red-Cockaded Woodpecker White Tree Band

Not unexpectedly, Red-Cockaded Woodpeckers used to be common throughout the original 90 million acres of Longleaf Pine forest, with an estimated 2-4+ million individuals total at the time of European colonization. And, also not unexpectedly, their numbers plummeted as the Longleaf Pine forest was cut down and converted in the 1700's to 1900's. When the Red-Cockaded Woodpecker was officially added to the Endangered Species List in 1979 (5 years after the Endangered Species Act was created), there were less than 10,000 individuals remaining, which was less than 1% of their historical population. Intensive conservation efforts were put in place to save the species. States started restoring and actively managing Longleaf Pine forests to expand available habitat for the Red-Cockaded Woodpecker. Officials began surveying forests for individuals and marking active nesting or foraging trees with white bands, so active "clusters" of Red-Cockaded Woodpeckers could be monitored year to year. These bands also allowed public and private landowners to know which trees to not cut down or tamper with. Officials also began creating artificial nest cavities in younger trees that Red-Cockaded Woodpeckers could not carve into, allowing them to nest more readily in forests that might not be "up to par" when it comes to the age factor.

Thankfully due to these intensive conservation efforts, the Red-Cockaded Woodpecker population has been recovering. A 2016 survey estimated the total population to be around 15,000 individuals and growing. And although their numbers are increasing, they are still listed as Federally Endangered, and probably will be for some time. The greatest threat to the individuals nowadays is continued habitat fragmentation and weather events. A large hurricane, for example, could wipe out nesting-age trees and individual woodpeckers themselves. When Hurricane Hugo made landfall in South Carolina in the fall of 1989, the winds toppled 87% of all the trees containing active Red-Cockaded Woodpecker cavities in Francis Marion National Forest, which then held the largest population of the species. With a population already highly fragmented, such events can easily knock out entire local populations or harm them enough to where they are no longer viable. Isolated and fragmented populations are much more at risk of extinction than highly connected and broadly spaced populations.

Red-Cockaded Woodpecker Santee Coastal Reserve

The continued population growth of the Red-Cockaded Woodpecker is a welcomed sight. These little woodpeckers are considered "keystone species.” A keystone species is a species that interacts with its environment in a way that either regulates or has a significant impact on many of the other species within that same environment. In the case of the Red-Cockaded Woodpecker, upward of 27 other vertebrate species, and many arthropod species, utilize old Red-Cockaded Woodpecker nest cavities in some form or another. Many of these species—including Eastern Bluebirds, Brown-Headed Nuthatches, and Wood Ducks—require such cavities to breed, but are unable to create the cavities themselves. Such species rely on the Red-Cockaded Woodpecker to create suitable cavities, and the extinction of the species would have a cascading effect on many other species within the Longleaf Pine forest ecosystem.

If you want to see a Red-Cockaded Woodpecker species yourself, one of the best places to visit is the Santee Coastal Reserve WMA. Not only is this WMA renowned for birding in general, but the Carolina Bird Club claims that “Many birders have gotten their lifer Red-cockaded Woodpeckers and Bachman's Sparrows” in the old-growth Longleaf Pine forest within the preserve. Regardless if you’re a birder, a herper, a botanist, or just someone who enjoys nature, a visit to Santee Coastal Reserve is not one you’ll regret.

No comments:

Post a Comment