Invasive species are non-native plants and animals that spread rapidly causing ecological and economic harm. Common examples are the emerald ash borer, Norway maple, and Asian clam. Invasive species are usually spread by humans. Once established, they become increasingly difficult to manage. Early detection of invasives is key to containment and practical management.
Nuisance species may be native or non-native, and may cause ecological and economic harm. Common examples are poison ivy and Canadian geese.
Last updated January 8, 2018