Invasive

June 23, 2022

Today’s NY Times morning feed referenced how invasive species were taking over the forests of Ohio. 

A new botanical survey of southwest Ohio found invasive species introduced to the US over the past century are crowding out many native plants.  Biologists from the University of Cincinnati are retracing two exhaustive surveys conducted 100 years apart to see how the areas plant diversity has changed over the past two centuries.  They focused their attention on undeveloped parts of cemeteries, banks of the Mill Creek, and public parks that have remained protected from development over the last 200 years.  The study was published in June in the open-access journal Ecological Restoration.  Horticulturists introduced most of the nonnative plants from Europe and Asia as ornamentals and their seeds spread in the wild.  The biggest culprit appears to be the Amur honeysuckle.

When I looked online, I found the Amur honeysuckle (Lonicera maackii) is a species of honeysuckle in the family Caprifoliaceae that is native to temperate western Asia.  The species name “maackii” is derived from Richard Maack, a Russian naturalist of the 19th century.  While the Amur is an endangered species in Japan, it escaped from cultivation and naturalized in New Zealand and the eastern US.  The plant is a large, deciduous shrub that grows to a maximum of 20 feet (6 m) tall with stems up to 4 inches (10 cm) in diameter.  The leaves are oppositely arranged and 2 to 3+1⁄2 inches (5–9 cm) long and 3⁄4 to 1 5⁄8 inches (2–4 cm) broad.  The flowers are produced in pairs, and commonly several pairs are produced together in clusters.  They bloom from middle of spring to early summer, beginning as a white color and later turning yellow or pale orange.  The fruit is a bright red to black, semi-translucent berry that contains numerous small seeds.  They ripen in the autumn and are eaten by birds, which disperse the seeds in their droppings.

The original survey on the area’s plant diversity was conducted by University of Cincinnati botanist Thomas G. Lea between 1834 and 1844.  Lea identified 714 species before he died in 1844and his work was published posthumously.  A century later the famed UC botanist E. Lucy Braun retraced Lea’s path and conducted a second plant survey in Cincinnati during 1934, finding more than 1,400 species.  Braun followed Lea’s meticulous notes to return to the places he visited, but many of the sites had been turned into roads, homes, or apartments.  The current study by UC biologist Denis Conover and Robert Bergstein retraced the steps of Braun and Lea in places where development did not pave the natural areas.  They found that many species purposely introduced as landscaping were flourishing in the wild.  Conover was quoted, “Native plants just don’t have a chance.  Everything that depends on the native plants — insects, birds — can be lost.”  Park managers and volunteers’ efforts to control invasive species has become a major part of their duties.  The study concluded the effort to control invasive species will be required in perpetuity and at great expense of both time and money.   

THOUGHTS:  Because of the invasive proficiency of the Amur honeysuckle growing the plant is illegal or controlled in parts of the US.  The species is named “invasive, banned” in Connecticut, “prohibited” in Massachusetts, as an invasive species in Tennessee, as an invasive species in Ohio, as a “Class B noxious weed” in Vermont, and as an invasive species in Wisconsin.  It has been suggested that plants growing outside their native range (eastern Asia) should be removed and replaced by non-invasive alternatives.  Talk about being unloved!  In the same vein, scientists are now concerned the first life we find on mars will come from the space junk we dump as spacecraft land on Mars after NASA’s small robotic helicopter Ingenuity captured images of mysterious wreckage last month.  You would think/hope we would learn.  Act for all.  Change is coming and it starts with you.