Zooming In: The Threat of Invasive Species Like Leafy Spurge on Prairie Skinks in Iowa
Its not uncommon for me to have a conversation with someone who wants to leave the weeds!
While I understand that sometimes not pulling all the dandelions around your tomato plants can be fine (especially because you can eat them)—on a larger scale—something as little as unchecked weeds can cause large downstream effects to the ecosystem. Today we are going to zoom in on an instance of how harmful invasive plants can be for one specific species: prairie skinks.
Every ecosystem is a delicate balance, no matter how robust. For this one interaction between an invasive weed and prairie skinks, there are thousands more interactions like this happening all at once. And yes—all because of one invasive species moving into the prairie.
All this to say, fighting and removing Invasive weeds is very important to the precious ecosystems of Iowa. They impact things in small little ways that can become really big ways over time. Without further ado—Leafy Spurge and Prairie Skinks!
Image by Peter Paplanus
The Threat of Leafy Spurge to Prairie Skinks
Leafy spurge is a perennial invasive weed that is native to Europe and Asia but has become highly invasive in North America, particularly in the Midwest. It grows aggressively in disturbed habitats, including those infamously weedy first-year prairies, and can outcompete native plants that provide essential resources for wildlife.
This species is thin and grows fast, making it hard to target with a sprayer because the other plants around it (that might be beautiful, precious native species) can get sprayed inadvertantly. The seeds are prolific, so once you get a strong stand, you will be fighting them for a while. And by a while, I mean years. Keeping them from going to seed is essential regardless of what other strategies you use to control them.
How Leafy Spurge Impacts Prairie Skinks:
Habitat Displacement: Prairie skinks require a variety of microhabitats within the prairie ecosystem—areas with loose, sandy soils where they can burrow and seek shelter. These areas are often found in places with a mix of grasses, forbs, and open spaces. Leafy spurge, however, forms dense, monotypic stands that crowd out native plants, particularly the grasses and wildflowers in sandy soils that prairie skinks need for food and cover.
This plant grows twice as fast in sandy soils as it does in clay soils.
Reduced Ground Cover: By outcompeting native grasses and other low-growing vegetation, leafy spurge limits the availability of ground cover that skinks use to hide from predators. This reduced cover can make skinks more vulnerable to predation.
Disruption of Food Sources: As an invasive plant, leafy spurge changes the composition of the plant community in a prairie. It displaces native grasses and wildflowers that support a diverse range of insects—many of which are essential food sources for prairie skinks.
Insect Population Decline: Native insects like grasshoppers, beetles, and ants make up the bulk of the prairie skink's diet. Fewer insects mean fewer food resources for skinks, which can lead to population declines if food becomes scarce.
Toxicity and Soil Changes: Leafy spurge is known for releasing allelopathic toxins that can affect both plants (preventing them from growing near it) and animals (can cause scours and sickness). Although prairie skinks are not directly poisoned by leafy spurge, the plant can alter the soil chemistry and make it less suitable for many native species, including the insects that skinks feed on.
Altering Soil Composition: Allelopathic toxin can cause changes to soil structure and nutrient levels, which may further inhibit the growth of native plant species that are crucial for maintaining a balanced ecosystem. As the composition of the soil changes, the health of the entire prairie system—including its insect and reptile populations—suffers.
Impact on Ecosystem Functionality: The invasion of leafy spurge can also affect the prairie ecosystem's overall functionality. By altering plant diversity and structure, leafy spurge disrupts pollination, seed dispersal, and nutrient cycling.
Restoring Prairies to Benefit Prairie Skinks: Managing Leafy Spurge
Effective prairie restoration involves managing invasive species to help prevent larger impacts like what we are discussing. Without controlling the spread of leafy spurge, it can quickly dominate and push out native plants that are essential for wildlife, including—in this case— prairie skinks.
Management Strategies for Controlling Leafy Spurge:
Mechanical Control:
Mowing: Mowing can be effective if done at the right time of year (before seed development).
Digging or Tilling: For small patches of spurge, physically digging up the plants or tilling the soil can help remove the root systems. However, this should be done carefully to avoid disturbing the prairie habitat (this method is not always applicable or recommended)
Herbicide Use:
In some cases, selective herbicide application may be necessary to manage dense infestations of leafy spurge. It is important to work with a professional to use herbicides that specifically target leafy spurge to minimize undesired impact.
Biological Control: *Not commonly practiced in Iowa, as of now!
Biological control methods, such as introducing natural predators of leafy spurge (e.g., certain types of beetles), can help reduce spurge populations without relying on chemicals. However, this method requires careful monitoring to ensure that the introduced species do not cause unintended harm to the ecosystem.
I think we will get to a point Biological Control is able to be used, but this is an uncommon practice as of now because of a variety of variables.
Promote Native Plant Growth:
After controlling any particular invasive species, it is important to replant native grasses, wildflowers, and other plants that support prairie biodiversity. The goal is to restore a healthy, diverse plant community that provides the habitat and food resources that species like prairie skinks rely on.
The Role of Prairie Restoration in Protecting Iowa’s Wildlife
As we work to restore Iowa’s prairies, controlling invasive species like leafy spurge is essential to ensuring that native wildlife, including the prairie skink, have access to the resources they need. Through active restoration efforts—such as managing invasive species, promoting biodiversity, and creating suitable habitats—we can help species like the prairie skink recover and thrive.
By focusing on prairie restoration, we can restore the balance of these unique ecosystems, allowing native plants and animals to coexist in a way that benefits both the environment and the species that call Iowa’s prairies home.
If you’re interested in learning more about prairie restoration or how to manage invasive species on your land, contact us here on our website for a consultation.
