Natives and Non-Natives as Successfully Urbanized Plant Species

Summary: William M. Fountain at the University of Kentucky and James R. Lempke of the State Botanic Garden of Kentucky accept natives and non-natives as successfully urbanized plant species.

closeup of flowers and foliage of trumpet honeysuckle (Lonicera sempervirens), Desert Demonstration Garden, Las Vegas, Nevada; Lonicera sempervirens, which is native to the central and eastern United States, receives competition for important pollinators, such as the ruby-throated hummingbird (Archilochus colubris), from non-native honeysuckle invasives such as bush honeysuckle (Lonicera maackii) and Tartarian honeysuckle (Lonicera tatarica): Stan Shebs, CC BY SA 3.0 Unported, via Wikimedia Commons

Cities ask a lot of all successfully urbanized plant species, according to Challenges for the Built Environment: When Native Species Meet Their Alien Relatives in the August 2011 issue of Arborist News.

William M. Fountain at the University of Kentucky and James R. Lempke of the State Botanic Garden of Kentucky break citified vegetation into two main groups. Groups of indigenous organisms, or natives, contain "any species (plant, animal, or microorganism) that was part of a natural community prior to the intervention of humans." They also describe all species that arrive unassisted by human activity, that migrate on their own or by natural efforts and that receive recent arrival status.

Native species such as black locust, native cane and poison ivy and recent arrivals such as armadillos and opossums also end up in the problematic group.

Any organism that is not originally from an area where it may or may not be currently living and reproducing fits into the group of non-natives.

Deliberate or unintentional movement into new locations by humans gives non-natives alien status and hybridized "mixtures of characteristics" from both parents when interbred with close-related natives. Aliens and non-natives hold exotic status when deemed "new, different, and appealing to humans" and escape status when they "reproduce from cultivated sources" as cultivated exotics. An invasive is the alien, exotic or non-native equivalent of the problematic native that affects the "web of life" and that encroaches on "currently occupied" habitats.

Aliens, escapes, exotics and invasives join ranks of naturalized non-natives and of successfully urbanized plant species by growing and reproducing in new locations without human assistance.

Atmospheric and soil moisture and temperature levels and food chains keep many non-natives from naturalizing, out-competing natives and sustaining populations "problematic to humans or native species."

Climbing, coiling rapid growth lets kudzu smother and suppress native plants, from ground-level to tree canopy, on "hundreds of thousands of acres" in the United States. Leafing out from early spring through late autumn and releasing allelopathic chemicals make it possible for bush honeysuckle and tree of heaven to outgrow native competitors. Local pathogens and pests need time to "adapt to being able to consume" recent non-native arrivals and to redefine with native species tolerable predation and victimization.

Built environments offer non-native species naturalization as successfully urbanized plant species since altered soils, changed hydrology, drying winds and reflected light compromise many native life cycles.

The absence of "the diseases and insects that have traditionally kept populations under control" prompts non-native species capable of reproducing rapidly to grow "with wild abandon." Restrained controls and unrestrained growth qualify as reinforcements of generalizations that "all non-natives are always bad" and contradictions of stereotypes that "All natives are always good."

Arborists, master gardeners, master naturalists and tree stewards recognize as survivors of "altered urban and suburban environments" natives and non-natives from flood plains and inhospitable climates. Human stresses shorten life cycles for even successfully urbanized plant species except when best management practices, plant and site compatibility and plant health care are prioritized.

What does not kill immunity from, resistance to or tolerance of pathogens, pests and poisons toughens companion-planted, species-diverse native and non-native plants in stress-prone built environments.

closeup of Tartarian honeysuckle (Lonicera tartarica), an Old World native shrub that joins other Old World successfully urbanized honeysuckle invasives, such as bush honeysuckle (Lonicera maackii), in competing with New World native honeysuckles for important New World pollinators, such as ruby-throated hummingbirds (Archilocus colubris): Algirdas, Public Domain, via Wikimedia Commons

Acknowledgment

My special thanks to:
talented artists and photographers/concerned organizations who make their fine images available on the internet;
University of Illinois at Urbana-Champaign for superior on-campus and on-line resources.

Image credits:

closeup of flowers and foliage of trumpet honeysuckle (Lonicera sempervirens), Desert Demonstration Garden, Las Vegas, Nevada; Lonicera sempervirens, which is native to the central and eastern United States, receives competition for important pollinators, such as the ruby-throated hummingbird (Archilochus colubris), from non-native honeysuckle invasives such as bush honeysuckle (Lonicera maackii) and Tartarian honeysuckle (Lonicera tatarica): Stan Shebs, CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Lonicera_sempervirens_close.jpg

closeup of Tartarian honeysuckle (Lonicera tartarica), an Old World native shrub that joins other Old World successfully urbanized honeysuckle invasives, such as bush honeysuckle (Lonicera maackii), in competing with New World native honeysuckles for important New World pollinators, such as ruby-throated hummingbirds (Archilocus colubris): Algirdas, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Totorinis_sausmedis.jpg

For further information:

Fountain, William M.; and Lempke, James R. August 2011. "Challenges for the Built Environment: When Native Species Meet Their Alien Relatives." Arborist News 20(4): 12-17.

Gilman, Ed. 2011. An Illustrated Guide to Pruning. Third Edition. Boston MA: Cengage.

Hayes, Ed. 2001. Evaluating Tree Defects. Revised, Special Edition. Rochester MN: Safe Trees.

International Society of Arboriculture. 2005. Glossary of Arboricultural Terms. Champaign IL: International Society of Arboriculture.

Marriner, Derdriu. 11 June 2011. “Tree Ring Patterns for Ecosystem Ages, Dates, Health and Stress.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/06/tree-ring-patterns-for-ecosystem-ages.html

Marriner, Derdriu. 9 April 2011. “Benignly Ugly Tree Disorders: Oak Galls, Powdery Mildew, Sooty Mold, Tar Spot.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/04/benignly-ugly-tree-disorders-oak-galls.html

Marriner, Derdriu. 12 February 2011. “Tree Load Can Turn Tree Health Into Tree Failure or Tree Fatigue.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/02/tree-load-can-turn-tree-health-into.html

Marriner, Derdriu. 11 December 2010. “Tree Electrical Safety Knowledge, Precautions, Risks and Standards.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2010/12/tree-electrical-safety-knowledge.html

Waliczek, Tina Marie; Jayne M. Zajicek, eds. 2015. Urban Horticulture. Boca Raton FL: Taylor & Francis.