What do European starlings, Japanese beetles, and earthworms have in common? All are invasive species in Minnesota.
Invasive species are non-native organisms that cause environmental, economic, or health-related damage. These species are able to thrive outside their native ecosystems by outcompeting local floral and fauna, disrupting natural environments and reducing biodiversity.
Among Minnesota's most prolific invasive species is buckthorn, a woody shrub that spreads rapidly and is notoriously difficult to eliminate. There are two main types—common and glossy—both of which produce berries that are commonly spread by birds. Because the seeds pass through birds undigested, buckthorn spreads quickly through woodlands and open spaces.
The most effective way to remove buckthorn is to cut the plant at the base and apply a topical herbicide to the stump. This is best done in late summer through fall. Once cut, experts recommend leaving the brush on-site to avoid spreading seeds.
Another problematic invasive species is garlic mustard, a fast-growing weed that grows well in disturbed or chemically affected soil. The Minnesota Department of Natural Resources (DNR) recommends preventing the spread of young garlic mustard plants in early spring by pulling them up, roots and all, before they can go to seed. Removed plants should be bagged and burned, as their seeds can remain viable and spread if left on the ground.
While invasive species pose a growing threat, individuals can take action. Cleaning shoes, bikes, and gear before entering and leaving natural areas helps reduce the spread of seeds. Learning how to identify and properly remove invasive plants is another way to protect Minnesota's native ecosystems.
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