{"id":2467,"date":"2010-07-07T15:45:05","date_gmt":"2010-07-07T19:45:05","guid":{"rendered":"https:\/\/extension.umaine.edu\/publications\/?page_id=2467"},"modified":"2024-05-23T09:59:16","modified_gmt":"2024-05-23T13:59:16","slug":"2536e","status":"publish","type":"page","link":"https:\/\/extension.umaine.edu\/publications\/2536e\/","title":{"rendered":"Bulletin #2536, Maine Invasive Plants: Invasive Plants Threaten Maine’s Natural Treasures"},"content":{"rendered":"\n

Developed by the Maine Natural Areas Program and University of Maine Cooperative Extension<\/em>.
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For information about UMaine Extension programs and resources, visit extension.umaine.edu<\/a>.<\/strong>
Find more of our publications and books at extension.umaine.edu\/publications\/<\/a>.<\/strong><\/p>\n\n\n\n

What’s the difference between a “weed” and an “invasive plant”?<\/strong><\/h3>\n\n\n
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\"oriental
Oriental bittersweet choking a tree<\/figcaption><\/figure><\/div>\n\n\n

A weed is simply a plant growing in a place where it\u2019s not wanted. It might be a problem locally, but it generally doesn\u2019t spread to become a large-scale problem in natural areas.<\/p>\n\n\n\n

An invasive plant is a non-native plant with very high reproductive potential and the ability to establish across long distances (for example, it might produce seeds that can spread by wind or by animals). An invasive plant can become established in natural areas, and disrupt natural communities by outcompeting native plants.<\/p>\n\n\n\n

Why are invasive plants suddenly a problem?<\/strong><\/h3>\n\n\n\n

The invasive plant problem is not new, but the problem is accelerating. Due to a history of low-intensity development and perhaps isolated watersheds, Maine\u2019s landscape has not been ravaged to the same degree as most other New England states. However, our good fortune will be short-lived if invasive plants continue to spread unchecked through our state.<\/p>\n\n\n\n

Where do invasive plants come from?<\/strong><\/h3>\n\n\n\n

About two-thirds of known invaders have been imported for ornamental and landscape plantings. These species include many of the Northeast\u2019s most troublesome plants: Japanese barberry, oriental bittersweet, Russian olive, Eurasian milfoil, purple loosestrife, and others. Other species have arrived as stowaways: Japanese stilt grass is used in packaging from Japan, and mile-a-minute weed is transported in soil.<\/p>\n\n\n\n

What problems do invasive plants cause?<\/strong><\/h3>\n\n\n\n

Invasive plants outcompete native species and agricultural crops, causing billions of dollars of damage each year. They affect forests, wetlands, lakes, streams, croplands, and pastures, and degrade many of our sensitive natural habitats. They grow rapidly, multiply, and spread to unmanageable levels in short periods of time.<\/p>\n\n\n\n

Invasive species are the second greatest threat to global biodiversity, after the loss of habitat. Invading plants outcompete native species for sunlight, nutrients, and space. They change animal habitat by eliminating native foods, altering cover, and destroying nesting opportunities. Some invaders are so aggressive that they leave no room for our natives.<\/p>\n\n\n\n

Invasive plants threaten Maine\u2019s natural and working landscapes. Their aggressive growth degrades our recreational experiences. Species like Japanese barberry and multiflora rose can form thorny, impenetrable thickets in forests. Other invasive plants choke waterways, limiting their use. Invaders increase the costs of agriculture and affect forest regeneration. And, these species mar the natural beauty of our regionally distinctive landscape.<\/p>\n\n\n\n

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\"porcelain
Porcelain berry swallows the land in Massachusetts.<\/figcaption><\/figure>\n\n\n\n
\"japanese
Japanese barberry, often used in landscapes, is invading Maine forests.<\/figcaption><\/figure>\n\n\n\n
\"japanese
Japanese knotweed infests a Kennebec River island.<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Are invasive plants being controlled?<\/strong><\/h3>\n\n\n\n

Controlling invasive plants is a challenge. Every year, more and more money is needed to combat them. Vermont has spent millions of dollars trying to clear its waterways of just two invasive plants species, Eurasian milfoil, and water chestnut. Florida spends $30 million every year managing invasive plants. Costs in Maine are creeping up as we work to control invaders in our state and national parks. Maine\u2019s Department of Environmental Protection and Department of Inland Fisheries and Wildlife now spend over $1 million each year on management and prevention of infestations of aquatic weeds \u2026 and we are just getting started.<\/p>\n\n\n\n

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\"water
Vermont spends millions each year controlling water chestnut, which has not yet invaded Maine.<\/figcaption><\/figure>\n\n\n\n
\"garlic
Garlic mustard is gaining a foothold in Maine forests.<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

What can you do?<\/strong><\/h3>\n\n\n
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\"giant
Exposure to the sap of giant hogweed sensitizes the skin to sunlight and results in swelling, blisters, and eruptions. If you encounter this plant in Maine, please report it to the Maine Department of Agriculture, 207-287-3891.<\/figcaption><\/figure><\/div>\n\n\n

Prevention is the key. Until recently, alien plants have benefited from our slow reaction to their damaging impacts. Invaders that are already widespread, like purple loosestrife, are here to stay. But species that have not reached Maine yet, like porcelain berry and mile-a-minute weed, need to be stopped. The damage invasive plants can do is well documented in other New England states. Learn about invasive plants, and avoid them. Your actions can make a difference. Don\u2019t help invaders get around in Maine.<\/p>\n\n\n\n