Invasive species are organisms that are likely to cause economic or environmental harm or harm to human health. Invasive species spread aggressively, reproduce quickly, tolerate a wide range of environmental conditions and habitats, and compete efficiently against other species. Ecological damage can result from invasive species outcompeting desirable, native species, reducing biological diversity, and altering ecosystem functions.
Invasive species can be either native or non-native species. (Native species are those which evolve naturally in an ecosystem.) Poison Ivy and Fox Grape are examples of species native to Maryland but considered invasive due to their ability to overtake an ecosystem and the safety and maintenance concerns they pose to our roadways.
Non-native species (also called alien or exotic) are species which have been introduced, accidentally or purposefully, into ecosystems in which they did not evolve. Non-native species may come from other continents or countries or even other parts of the United States.
While some non-native species are not problematic, many non-native species disrupt the natural balance of an ecosystem and their aggressive growth patterns cause safety and maintenance concerns along our roads and highways. Johnsongrass, Canada thistle and Shattercane are non-native species that the State of Maryland has declared to be noxious weeds. The Maryland Weed Control Law requires landowners, including State Highway Administration, to manage any and all noxious weeds found on their land.
SHA encourages the use of native species for roadside landscaping whenever possible. Although landscape beds and roadside plantings usually include a mix of both native and non-native species, SHA works closely with the Maryland Invasive Species Council and other agencies to identify and discontinue the use of species considered to be invasive.
SHA initiated several projects to remove invasive plants along our roadsides and restore these areas with meadows or reforestation plantings comprised of native species adapted to the local environment. Examples of these projects have occurred on the I-83, I-95, and US 301 corridors.
Many rare and endangered native plants and animals require specialized environments to survive. It is important to protect the streams, wetlands, and forests where they grow. Controlling invasive species and restoring native plant communities are ways that we can help vulnerable native species to reproduce and thrive for future generations.
Source: Maryland Invasive Species Council
707 North Calvert Street
Baltimore, Maryland 21202-3601
Main Business Line – 410-545-0300
Safety Campaigns – 1-800-323-6742
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