Plant Survey Reveals Alarming Presence of Nonnative Invasive Species in Southwest Ohio

A recent plant survey conducted by researchers from University of Cincinnati and the Cincinnati Museum Center has revealed that dozens of nonnative invasive plant species are thriving in southwest Ohio, posing a serious threat to the native biodiversity and economy of the region.

What are invasive plants and why are they a problem?

(Photo : JUSTIN TALLIS/AFP via Getty Images)

Invasive plants are plants that have been introduced to a new area, either intentionally or accidentally, and have the ability to spread rapidly and outcompete native plants for resources.

Invasive plants can cause ecological, economic, and social impacts, such as:

•  Reducing the diversity and abundance of native plants and animals, which can affect ecosystem services and functions, such as pollination, nutrient cycling, and water quality.
•  Altering the structure and function of natural habitats, such as wetlands, prairies, and forests, which can increase the risk of erosion, flooding, fire, and disease outbreaks.
•  Damaging crops, pastures, and forests, can reduce agricultural and forestry productivity and increase management costs.
•  Affecting human health and well-being, by producing allergens, toxins, or thorns, or by harboring pests and pathogens.

According to the Ohio Invasive Plants Council, of the approximately 3,000 plant species known to occur in the wild in Ohio, about 75% are native and 25% are non-native.

Of the non-native plants, fewer than 100 are known to be problems in natural areas.

Also Read: Invasive Species May Beat Climate Change to Extinction of Endangered Plants

What did the plant survey find and what are the implications?

The plant survey, which was published in the journal Biological Invasions, involved collecting and identifying over 2,000 plant specimens from 14 counties in southwest Ohio between 2015 and 2019.

The researchers found that 163 of the 1,021 plant species recorded were non-native, and 66 of them were invasive.

Some of the most widespread and problematic invasive plants in the region include:

Amur honeysuckle (Lonicera maackii)

This is a shrub that forms dense thickets and shades out native plants, reduces wildlife habitat and alters soil chemistry.

Garlic mustard (Alliaria petiolata)

This is a herb that produces chemicals that inhibit the growth of native plants and fungi, and reduces the food sources for native butterflies and other insects.

Japanese knotweed (Fallopia japonica)

The Japanese knotweed is a herb that grows rapidly and forms dense stands that crowd out native plants, damage infrastructure, and increase erosion and flooding.

Multiflora rose (Rosa multiflora)

This is a shrub that forms impenetrable thickets that hinder the movement of wildlife and humans, and host diseases and pests that affect native roses and other plants.

Tree-of-heaven (Ailanthus altissima)

The tree-of-heaven is a tree that produces chemicals that prevent the growth of other plants, and has roots that can damage buildings, roads, and pipes.

The researchers also found that some invasive plants, such as autumn olive (Elaeagnus umbellata), common buckthorn (Rhamnus cathartica), and princess tree (Paulownia tomentosa), have expanded their range and abundance since the last comprehensive plant survey of the region in the 1940s.

The findings of the plant survey have important implications for the conservation and management of natural areas in southwest Ohio, as well as for public awareness and education about invasive plants.

The researchers suggested that more efforts are needed to prevent the introduction and spread of invasive plants, to monitor and control their populations, and to restore native habitats and species.

They also recommend that the public should avoid planting or disposing of invasive plants in their gardens or yards, and should report any sightings of invasive plants to local authorities or organizations.

Additionally, they encourage the public to learn more about invasive plants and their impacts and to participate in volunteer activities such as invasive plant removals, native plant plantings, and citizen science projects.

Related article: A Number of Invasive Plants Still Being Sold on the Market Despite Being Banned in US