The Tree-of-Heaven (Ailanthus altissima) is a non-native, invasive tree species found throughout the United States and North Carolina. Originally introduced from Central China in the 1780s, this invasive species most often occupies woodland borders and edge communities near logged oak and loblolly pine stands locally.
The Tree-of-Heaven can be identified by its large pinnately-compound leaves, with one- to two-dozen leaflets that smell like burnt peanut butter when torn or crushed. These leaves sit alternately on the branch of the tree, and when the leaves drop, they leave behind a heart-shaped leaf scar. The bark of this tree is gray, and young trees often are dotted with corky lenticels; older tree bark looks like the rind of a cantaloupe.
The Tree-of-Heaven is known for its incredible growth, with stump spouts growing an inch a day and up to 80 feet in just ten years. While these trees don’t live long, only up to 70 years, they can clone themselves from root sprouts. It is said that the first Tree-of-Heaven planted in the Bartram Botanical Garden in 1784 lived until the early 2000s!
Tree-of-Heaven also produces allelopathic chemicals, which can suppress the growth of other plants. Combined with incredible growth and the ability to grow from stumps, Tree-of-Heaven is difficult to control and it is spreading. Today, tens of thousands acres of the American South are covered by Tree-of-Heaven and the plant is making fast in-roads into South Carolina and Georgia. Thus, Tree-of-Heaven is considered to be an aggressive invader that is threating native ecosystems across the country.
In August, we often find Ailanthus Webworm moths, slender moths with bright orange, white, and black markings. This moth is native to south Florida, where it feeds on the native paradise tree, but now its range is expanding with a new food source: the Tree-of-Heaven!
A Note on Language
What is a non-native species? A non-native species is a species living outside its native distributional range.
What is an invasive species? A species that spreads to an extent that harms the environment, economy, or human health. Many definitions of invasive species suggest that they are also non-native.
What is a non-native invasive species? A non-native species that spreads to an extent that harms the environment, economy, or human health.
A note on language: Samantha Nurmi, a former graduate student in the Nicholas School of the Environment, has contributed the following to describe the nuances of language, and specifically, the xenophobic associations with the language around non-native species [modified and used with permission, 22 Sep 2021]:
Every word has both a denotation, a literal meaning or definition, as well as a connotation, an emotional or cultural association. For example, environmental curricula commonly address “invasive species” and the negative impact they have on the environment. Unfortunately, terms such as “invasive”, “alien”, and “exotic” are problematic and confusing within both the academic and social spaces. Each term holds a slightly different scientific meaning, yet they also evoke political ideas. This is supported by the literature, and as Iannone et al. (2021) states, “Despite being synonymous with the term nonnative, these terms are often used when referring to global movement of humans”. Thus, these words carry with them polarizing connotations and xenophobic tendencies. Scientific terminology should not evoke political debate, but rather should clearly explain what the species is and how it impacts the environment around it.
Crawford (2018) suggests that “Consolidating around consistent terminology is [incredibly] important for the field, and for us to communicate to others … as we translate science into policy and management”. We need to standardize the terminology so that it is clear and avoids xenophobic or racist connotations. The best way to aid this shift in terminology is to be cognizant of the origins and connotations of the labels we are using. For example, instead of saying that a plant is an “alien species” call it an “non-native species”. This simple change in dialogue replaces a word linked to centuries of systematic oppression, xenophobia, and discrimination with a word that has the same denotation but does not carry any negative connotations.
References
Crawford, Amy. “Why We Should Rethink How We Talk about ‘Alien’ Species.” Smithsonian.com, Smithsonian Institution, 9 Jan. 2018, http://www.smithsonianmag.com/science-nature/why-scientists-are-starting-rethink-how-they-talk-about-alien-species-180967761/.
Iannone, B. V., Carnevale, S., Main, M. B., Hill, J. E., McConnell, J. B., Johnson, S. A., Enloe, S. F., Andreu, M., Bell, E. C., Cuda, J. P., & Baker, S. M. (2021). Invasive Species Terminology: Standardizing for Stakeholder Education. Journal of Extension, 58(3). Retrieved from https://tigerprints.clemson.edu/joe/vol58/iss3/27
Sense of Place 