Non-native species, also known as exotic, alien, or introduced species, are defined as species that occur in a certain place due to deliberate, accidental, direct, or indirect human actions. Both animal and plant species can become established in the wild when they are brought into an area that meets their living requirements. Many non-native plant species begin as ornamental landscape plantings, while non-native animal species often become established due to humans releasing them outside of their normal range.
Invasive species are aggressive, non-native species that cause harm to the environment, economy, or human, animal, or plant health. They are capable of displacing native species, and therefore threaten the diversity and integrity of native communities. Invasive species found in the park include plants like English ivy (Hedera helix) and animals like the emerald ash borer (Agrilus planipennis).