During the Biodiversity 2 lecture, one component that was cited as a threat to biodiversity is invasive species. Invasive/non-native species can decrease biodiversity through a number of means:
- Out-competing native species
- Changing invaded habitat (which may make it unsuitable for native species)
- Directly prey upon native species
- Hybridization with native species
Just to name a few. Asian carp, zebra and quagga mussels were discussed in class. Many other invasive species have spread throughout Michigan and are easy to spot! Here are a few common plant invasives that you may have seen:
Purple loosestrife – This invasive is native to Eurasia (Lythrum salicaria) and was brought to the U.S. as an ornamental and medicinal plant in the 1800s. Now, purple loosestrife has been reported in all states except Florida. Due to its high levels of fecundity (an adult purple loosestrife can produce two to three million seeds annually) and ability to flourish in disturbed habitats, purple loosestrife has been able to spread easily. In Michigan, purple loosestrife can frequently be easily spotted along the sides of highways.
Garlic Mustard (Alliaria petiolata) – Originally from Europe, this invasive was introduced to the U.S. via Long Island in the 1860s. Garlic mustard can now be found throughout the eastern United States. Garlic mustard thrives in the understory where it has been demonstrated to displace native plants and alter forest communities. One aspect of garlic mustard that makes it a good invader is that its seeds may remain viable for up to five years. The good news? Garlic Mustard is delicious, good for you, and edible.
Autumn Olive (Elaeagnus umbellata) – This shrub originally hailed from eastern Asia but was introduced to the United States in the 1830s. Because autumn olive can fix its own nitrogen, it is able to grow in inhospitable habitats. Though Autumn Olive was previously used to create wildlife habitat, this plant has been demonstrated to crowd out native species. One good aspect of Autumn olive is that it produces numerous berries that are not only edible, they are good for you! Autumn olive contains a large amount of lycopene which is a phytonutrient that may reduce risk of cardiovascular disease.
There are many ways to combat invasives: biocontrols, increased vigilance to decrease their spread, etc. One way that receives less attention: eating! Recipes are available for asian carp, garlic mustard, autumn olive, and many other invasives. In fact, Bradford Street Press has a cookbook dedicated to “Conservation through Gastronomy.” Here’s the link: http://www.bradfordstreetpress.com/
Swearingen, J. 2009. WeedUS Database of Plants Invading Natural Areas in the United States: Purple Loosestrife (Lythrum salicaria). http://www.invasive.org/weedus/subject.html?sub=3047.