Terminology

I have been rereading Roy Bedichek’s Adventures with a Texas Naturalist, a Texas classic published in 1947. Bedichek’s book has a mid-century optimism lacking in the sense of eco-urgency we expect of naturalist writers today. In the first two chapters about fences, Bedichek, while lamenting the loss of prairie habitat due to farming and grazing, was quite upbeat about the preservation of native species on highway and railroad rights-of-way. He extolled the benefits of native habitats along the continuous and interconnected highways, protected from grazing and plowing by the fencing that was meant to protect cars from livestock or livestock from trains. However, it struck me that he said little about the possibility that highways could become major pathways for the spread of invasive species.

When did naturalist writers begin writing about invasive biology? Henry David Thoreau does not mention the concept of invasive plants in Walden (1854). The term did not exist in his time. However, he did write extensively in journals and books, including Walden, about the local flora of Concord, Massachusetts. His detailed observations serve as a crucial historical baseline for modern scientific research. John Burroughs (1837-1921) authored essays about species that were non-native to specific areas, though he did not use the modern term “invasive species.” While John Muir (1838-1914) did not use the term as it is understood today, his writings did discuss a similar concept: the destructive impact of non-native livestock, particularly sheep and cattle. In A Sand County Almanac (1949), Aldo Leopold mentioned invasive plants, particularly cheat grass (Bromus tectorum). He discussed the negative impacts of non-native species on native ecosystems and the role of human activity in their spread. Edward Abbey mentioned invasive plants in Desert Solitaire: A Season in the Wilderness (1968). He specifically referred to the non-native Russian thistle (Salsola), commonly known as tumbleweed, as an “invasive pokey” plant that clogs paths in the desert environment. Annie Dillard mentioned the invasive European starling in her book, Pilgrim at Tinker Creek (1974). She described how the bird was introduced to the United States by people seeking to bring all birds mentioned in Shakespeare’s plays to North America.

The specific phrase “invasive species” first appeared in the September 1891 issue of The Indian Forester, a 150-year-old journal on scientific forestry and allied disciplines. The phrase was used by British forest administrator R.S. Troup in his book, Silvicultural Systems (1928), where he mentioned “Various invasive tropical species [of tree] which habitually spring up in quantity on recent clearings.” However, “invasive species” was not widely used, including by our naturalist writers, until Charles S. Elton wrote The Ecology of Invasions by Animals and Plants (1958). Elton’s book is considered a foundational text for the study of how invasive species affect ecosystems. While Elton popularized the modern concept of invasion ecology, the exact two-word phrase, “invasive species,” was first used in the forestry journal.

Coda: We have come a long way since 1958 in our understanding of invasive species. This from Wikipedia will bring you up to date on the current terminology. The preferred terms in current use include:

Native. A species that naturally occurs in a specific geographic region.

Nonnative. A species that does not naturally occur in a specific region but has been introduced.

Introduced. A species that has been brought to a new area, often by humans.

Established. An introduced species that can reproduce and sustain a population on its own without human support.

Invasive. A nonnative species that spreads aggressively and causes harm to the environment, economy, or human health.

Nuisance. An individual or a group of individuals of a species that causes problems, even if they are native. For example, a native species can become a nuisance if it grows in an undesirable location.

(Note: I stole much of the above from Google and Wikipedia, who stole it from others.)