Invasive Plant Species at the Park

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 Wild parsnip is a highly invasive plant and if ignored can spread rapidly, developing into large monocultures that replace native animal and plant habitat. 

The plant sap contains chemicals that are activated by sunlight and can cause serious burns and blisters to human skin after contact. If you know you have touched it or walked through it, cover the exposed area from sunlight and wash with soap and warm water when you get home. Usually, casual contact while hiking is minor.

Bush Honeysuckle is prolific in unrestored areas of Prairie Moraine park and produces deep shade below on the forest floor. 

 Deep shade for longer periods of time suppresses the growth of native understory plant cover.  As a result, the abundance and diversity of native forest understory species is decreased, regeneration of native trees is reduced, and forest ecosystems are altered. 

The linked article below deals with buckthorn alone, but the effects are the same for both buckthorn and bush honeysuckle.  Buckthorn can be the worse of the two because it also has alleopathic qualities, which means it secretes chemicals that inhibit the growth of neighboring plants and beneficial soil fungi.

"The leaves of buckthorn contain as much as five times more nitrogen and are also known to decay much more rapidly than leaves of other forest trees.  The rapid and near complete decomposition of buckthorn leaves on the forest floor result in extensive areas of unprotected bare ground beneath stands of buckthorn."  So, in addition to reducing biodiversity, buckthorn also leads to increased soil erosion. 

Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Garlic mustard invades forest understories and rapidly takes over.   Of all plant groups, tree seedlings declined most notably with increasing levels of invasion.  

August, 2021:  After an alert from park user (and restoration ecology professional) Ben Yahr regarding an early-stage infestation of Japanese Hedge Parsley almost ready to seed, and a quick consultation with Parks Naturalist Lars Higdon on the best way to deal with the problem, the volunteers went into action. 

Multiflora rose spreads quickly and forms dense thickets.  It is thorny and extremely difficult to remove.

Ecologically not too serious, but for dogs ... a disaster!

Despite the bad reputation Goldenrod held with many allergy sufferers for so long, it is Ragweed and not Goldenrod that produces all those nasty allergens.  Unfortunately, there is a LOT of Ragweed, both Common and Giant, in Prairie Moraine Dog Park.

Gray Dogwood - front, left

This is a native Wisconsin species, but its control is important -- even critical -- in both prairie and savanna restoration efforts because of its tendency to spread and rapidly fill any open area, frequently to the exclusion of other species.