By Clint Calhoun
Tough is a word that is often used to metaphorically describe adverse conditions or situations that require a certain amount of fortitude or resilience to overcome. It also can be used to describe someone or something that has resilience. In western North Carolina, a popular description of someone who shows such a degree of fortitude would be that they are “tough as a pine knot.” In other words, they can take whatever comes their way. We can also use the word to describe plant and animal species.
The Party Rock Fire has brought a lot of attention to the health of our forests and myself and others have already written or spoken a great deal about the resilience of our forests and their ability to quickly recover from natural events, but we have not talked too much about individual species. Obviously, some species are “tougher” than others when it comes to their ability to tolerate major changes in the natural environment. Certain species such as red maple and tulip poplar tend to show less tolerance and resilience when faced with fire, while others show a greater tolerance and are in fact genetically adapted to use fire to their advantage.
Table mountain pine (Pinus pungens) certainly meets the description of tough and is one of the species that will benefit the most from the recent fire. Most of the time, when pine comes up in the conversation of most people, it is usually not favorably. Most people consider pine to be trash trees, at least in terms of their aesthetic value, though they certainly have value in the lumber industry. Most of the stigma comes from species such as Virginia pine which is an early successional species that tends to be scrubby and unattractive, and is mostly used for pulpwood, although larger trees can be used for lumber. Table mountain pine, on the other hand, generally has little value as a lumber species, but has great value aesthetically and as a wildlife food source.
Table mountain pine is an Appalachian endemic and mostly occurs at elevations between 3,000 and 4,000 feet, but occurs at lower and higher elevations in scattered locations throughout its range. Individuals almost always look stunted as they do not grow very tall, but their canopy is often wide, giving them a giant bonsai look. Table mountain pines grow in tough conditions. Sites are usually very dry, rocky, thinly soiled, and often exposed to high winds. Individuals compete for soil with mountain laurel and other shrubs, as well as oaks, which are most commonly associated with table mountain pines. Such conditions require inhabitants to be tolerant of drought and able to survive with limited nutrition. Here in Hickory Nut Gorge it’s found in scattered locations, mostly on exposed ridges, outcroppings, and edges of granite domes. Some of the best places to see table mountain pines are Exclamation Point on Chimney Rock Mountain, Eagle Rock on the north side of Shumont Mountain, and along the ridge of Rumbling Bald Mountain.
In addition to growing in tough conditions, table mountain pines are physically tough. They have thick, scaly bark that is incredibly fire resistant. Their needles, which grow two to the bundle, are 1.5 to 2.5 inches long, are thick and sharp. Their 2 to 3 inch cones are heavily armed with spines on each scale and usually occur in bunches of 3 or 4. The cones are closed until they reach maturity, at which time some may open and release seed if conditions are right. Cone opening is related to temperature which is why fire so easily serves as the catalyst for seed germination. Heat from fire will warm the cones sufficiently enough to melt the resin within the cones that essentially glues the cones closed until they are ready to drop seed. Table mountain pine cones will also open from heat exposure on hot, dry slopes. Temperature must be at least 95 degrees Fahrenheit to open table mountain pine cones.
Besides needing heat to open their cones, table mountain pines need open, exposed ground to set their seed. Fire does a great job of burning off accumulated leaf litter and topkilling mountain laurel, opening up the forest floor to sunlight and providing the growth medium needed for seeds to germinate and grow before other competitors have a chance to re-establish. The seedlings will extend a long taproot down into cracks in the rocky substrate upon which they grow, anchoring them to the ground, at the same time spreading lateral roots throughout the soil or duff layer to collect moisture and nutrients.
In addition to being tough, table mountain pines are incredibly patient, waiting for the right conditions to produce seed. This means that individuals have the ability to bank their seed within their cones for several years. Some will spontaneously open without a heat trigger, but most require a heat trigger such as fire to open.
As fire was raging across the ridge of Rumbling Bald and made its way to Eagle Rock, within minutes, mature table mountain pine cones began to open, dropping their seed shortly after the fire abated. Already representatives from the NC Forest Service have reported seeing new table mountain pine seedlings, quickly taking advantage of the newly exposed ground. Many of the table mountain pines, because of where they grow, were exposed to very high temperatures during the fire, causing their needles to yellow or turn brown. Some of these trees will regenerate their needles, others may regenerate from their root crown, and still some may actually die. Such is the way nature works. Fortunately, in almost every place where fire burned through table mountain pine stands, cones opened and long-banked seeds were released, ensuring continuation of the species and starting the waiting game all over again.
Toughness is a quality that I have always found to be admirable, as it shows an ability to not only withstand but to also adapt. Toughness is what helps us to persevere in those hard situations that we are faced with. Survival in nature, as well as life, requires significant toughness. Table mountain pine is certainly a great example of this amazing quality. Hopefully as we see how the forest recovers from the fire, we will see other great examples of resilience and toughness. Until Next Time!
Clint Calhoun is a naturalist and biologist and has worked in Hickory Nut Gorge for over 20 years. He is currently the Environmental Management Officer for the Town of Lake Lure. Check out Clint’s blog at http://clintcalhounadventures.blogspot.com.