Impacts of Invasive Species

Impacts of Invasive Species

What is an invasive species? Why do they matter? Learn about all that and more in honor of Invasive Species Awareness Week!


This week marks Hamilton County’s Invasive Species Awareness Week! Here at Carmel Clay Parks & Recreation we are no strangers to invasive species. In fact, much of the land management we do in our parks relates to removing invasive species to allow room for native species to thrive.

To begin, invasive species are non-native or exotic species that cause harm to the economy, the environment, and/or human health. Non-native species come in many different shapes and sizes but those labeled as “invasive” mean they are doing serious harm. Just because a plant is non-native does not necessarily mean it is also invasive. In fact, “Of the roughly 2,300 plant species growing outside of cultivation in Indiana, approximately 25 percent are non-native.” (Indiana Native Plant Society, 2021).

Many of us have non-native plants growing in our landscapes at home and they are causing no harm. The issue with invasive species is the fact that they do indeed cause harm. They cost hundreds of thousands of dollars to control, and they displace many of our native plants and animals. Bottom line: If we stick to planting native species as opposed to non-native species, we won’t have to worry about the issue of our non-native species becoming invasive.

What makes invasives…invasive?

So, what qualities make a plant “invasive” and how can you spot invasives growing in a landscape? It’s a good question to ask when looking in your own backyard and the natural areas around you. Typically, invasives are introduced from another continent or climate and they grow so dense that they become a monoculture where only one type of plant grows exceptionally well. If you see a monoculture in a natural landscape that has barely anything growing around it, take a closer look as it may be invasive. Furthermore, invasive species have no natural controls that keep them in check in their new foreign environment. Native species have evolved with their local ecosystem over long periods of time and have adapted in a way that allows for them to be part of the natural environment with a healthy system of checks and balances.

Another quality of invasive species is the ability to outcompete our native species thorough chemical defenses. Many invasives have toxins within their roots and even plant structure that emit into the soil and kill other plants around them. Take invasive bush honeysuckle, for example. Asian bush honeysuckle is one of the worst invasives in Hamilton County and beyond. Not only do they shade out other natives with their shrubby structure, but they also release chemicals into the soil that inhibit plant growth and eventually poison the soil. The bright red berries that are often easily identifiable on bush honeysuckle in the fall can be consumed by wildlife, however, they do not provide the high nutrient content that migratory birds would benefit from as they prepare for their long flights before winter. Instead, the berries are very rich in carbohydrates and sugars providing smaller, shorter bursts of energy.

All of these various impacts that invasive species have on our native landscape ultimately lead to a loss in biodiversity. As we know, biodiversity is what supports our earth and makes up the food web around us. Life simply depends on plants as a part of this food web. Insects and herbivores are adapted to feeding on native plants and many of these species choose only certain plants to eat. Just think about the monarch butterfly that we all know and love. The larvae of the monarch butterfly only eat the leaves of milkweeds. Without milkweed for the larvae to eat, there would be no monarch butterflies. It’s all part of the interwoven food web.

CCPR works to make a difference

At Carmel Clay Parks & Recreation, we realize that to have a balanced and healthy ecosystem with native plants as the foundation, we must work to remove invasive species. Getting rid of the bad and installing the good will provide essential habitat and food supply for all the critters that call our parks home.

If you want to join our fight against invasive species, stay tuned to our seasonal program guide! We always have nature programs and volunteer events planned to help our natives or rid our parks of invasives, and we’d be happy to have you join us!


Indiana Native Plant Society (2021). What’s an Invasive Plant? Retrieved from on May 12, 2021.

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