Ailanthus: A Nonnative Urban Tree Is Causing Trouble in Our Forests
Ailanthus, the so-called tree-of-heaven, is probably the most famous invasive tree in the United States. It’s the title tree in Betty Smith’s classic 1943 novel A Tree Grows in Brooklyn, where it is used as a metaphor for persistence and toughness in the face of adversity. However, that toughness makes this tree— Ailanthus altissima (aka ailanthus, tree-of-heaven, stink tree, and Chinese sumac)—a serious problem wherever it grows. It usually grows in urban settings, industrial wastelands, and mine spoils, and along railroad and highway corridors. It survives in hot, dry, and toxic soils, and sends down its roots around and through concrete and paving cracks. It sends out seeds in enormous numbers, smells bad, and is allelopathic (toxic to other plants). Ailanthus can create dense clonal thickets, almost monocultures. It grows very quickly, often displacing native plants, which may affect wildlife. It is extremely difficult to eradicate, and cutting down the trunk and/or pesticide treatment only result in new shoots growing up from the roots.
View the Spring 2014 Research Review (3.4 MB PDF)
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St. Paul, MN 55108