The Rubrum Cunundrum
Over the vast many years that I have been interacting with our region’s forest practitioners and enthusiasts, I have observed that many of us harbor a profound and deep emotional relationship to particular species of trees. These emotions run the gamut from effusive adoration to downright animosity. Some species are almost unanimous in the passions that they invoke; from the pleasing attributes of the stately white oak (Quercus alba) to the displeasing attributes of the noxious tree-of-heaven (Ailanthus altissima). Some species are more subtle and our sentiments are derived by how we personally value specific qualities. Sweetgum (Liquidambar styraciflua) is a good example. If you are a birder you may love to see this tree prevail on your land because it can be an important avian food source; providing seeds during fall and winter and attracting many species of Lepidoptera during the spring and summer. Sweetgum does not provide a quality food source for most game species, however, so a sweetgum dominated landscape may cause ire to landowners looking to attract game. Sweetgum’s brilliant autumn foliage is aesthetically pleasing for folks but at the same time its nefariously spiked seedpods are potential hazards to partially clad feet. We are complex organisms, so our emotions about a species may not be so fixed. Black locust…anyone? How about American beech?
The tree that I seem to have the most complicated relationship with is the ubiquitous red maple (Acer rubrum). Red maple, by far, is the most abundant and widely distributed tree species on the entire eastern North America with a native range from Manitoba to Newfoundland in the north and from Texas to Florida in the south. In our Chesapeake region, according to US Forest Service Forest Inventory Analysis (FIA) data, it is three times more abundant than the second most numerous species, loblolly pine. You probably don’t need FIA data to tell you that red maple grows almost everywhere. You can find it growing along dry ridges of our mountains all the way down to the poorly drained edges of our tidal wetlands and throughout our urban and suburban areas.
Red maple is considered to be a super generalist in its resources needs, and therefore can be found in a variety of soil types, climates and elevations. Although it grows best on well drained moist loamy soils, the species is well adapted to a variety site conditions. For instance, red maple saplings can produce well developed lateral roots and shorter taproots on wet sites and long taproots and shorter lateral roots on dry sites. This adaptation allows it to better tolerate both flooding and drought. (Burns & Honkala)
Red maple, despite its abundance today, is estimated to only have comprised 5% of the forest area in North America when Europeans first arrived and, although still widely distributed geographically at that time, they were mainly found in riparian areas, thusly earning the name swamp maple by early settlers. (Burns & Honkala). Red maple has increased exponentially on the landscape for a variety of reasons beyond its ability to tolerate a wide range site conditions and climates. They can produce flowers in as little four years and are prolific seeders, often producing bumper crops every two years. These seeds, which are produced early in the spring, germinate soon after hitting the ground, and new seedlings take advantage of a longer growing season. Both natural and anthropogenic disturbances over the years has opened up our forests and given red maple an opportunity to spread into new sites. Suppressing fire from the landscape too has aided the success of red maple establishment and proliferation, especially in our oak dominated forests. The thinner barked maples are highly susceptible to even low grade surface fire. Native Americans had been using fire long before Europeans arrived as a technique to maintain dominance of higher valued trees like oaks, chestnuts and hickories. Red maple’s proliferation throughout eastern forests is changing the ecology of our forests now and for the foreseeable future and displacing tree species that often have higher ecological and economic value.
Now, I am not trying put all of this ecological discord on the red maple. We humans are, obviously, the cause of the drastic changes to our forests (development, high grading, invasive species, air pollution, deer, etc.). This is why I remain conflicted about my perceptions of red maple, the tree. To be honest, it is a pretty freaking awesome tree with attributes we all can value. Red maple is one of the first deciduous trees to break dormancy during winter. Think about the long winter we endured this year and what a joy it was to see the crimson buds of the red maple swelling early in a canopy of gray stupor. It gave me hope anyway. Red maple flowers are set soon after bud break and typically before it unfurls its leaves. Although these flowers are generally wind pollinated, they provide a vital early food source for various pollinators like bees.
Red maple trees are also tapped for maple syrup production. Sugar maple, obviously, is the gold standard in maple syrup production due to the higher sugar content in its sap, but red maple ultimately supplements the amount of syrup being produced each year. It may play a more prominent role in the industry as species shift and sugar maple becomes less abundant in our region.
Red maple is a viable wood product as well. Although its value pales in comparison to other hardwoods in our region like oaks and black cherry, red maple, which is often classified as soft maple, is readily harvested as sawtimber and pulpwood and used to make such things as furniture and cabinets. Maple, in general, is considered to be a tone wood and red maple is often used by North American luthiers in the production of guitars, mandolins, fiddles and other fine stringed instruments.
Due to its ability to thrive on various sites, red maple is valuable tree to incorporate in forest restoration and riparian buffer plantings. There will probably be several people reading this that are wondering why on earth would I want to plant more red maple when I just emphasized that their numbers are already exploding. I know – great question. Remember, I am conflicted here. We do incorporate a high diversity of trees in our plantings, especially oaks. Sometimes on certain sites we just need to get trees established quickly in order to restore the site, and well, as mentioned earlier, red maple is really good at doing that. It is reassuring to see trees growing out of five foot shelters after just one growing season.
That was my arboreal confession. We all know that the trees in our woodlands provide us benefits. It is important (and fun) to learn about the attributes of your trees. Your woods are not static and will change whether you plan for it or not. The science of silviculture and its practices were developed out of our need to sustain our woodlands and the myriad of values they provide. I encourage you to discover or reinforce what it is you enjoy about your woodlands and come up with a plan to sustain this. The Forests for the Bay website has a vast amount of information and resources to connect you.