The Indiana Dunes is an area of land beside Lake Michigan, in the State of Indiana, United States. It includes Indiana Dunes National Park and Indiana Dunes State Park. Non-native plant species, specifically invasive species, have colonized that area. Invasive plants are those plants that aggressively spread throughout an area and out-compete other plant species, normally those that are native to the area.

Negative impacts Invasive plant species in the Indiana Dunes have several negative impacts. They may: Displace the variety of flowering plants, substituting a monoculture Grow densely around trails, roads, and water, making travel difficult or impossible Introduce toxins into the environment Have unpleasant spines or thorns Smother ponds, killing fish

Specific examples include: Purple loosestrife – establishes a monoculture, reducing the variety of wildlife.The Singing Sands; National Park Service, Indiana Dunes National Lakeshore, Summer 2009, Vol. 30 No.1 Bush honeysuckles – prevents regeneration of woody plants and herbs, reducing bird habitat. Glossy buckthorn – prevents regeneration of woody plants, slowly destroying forests. Garlic mustard – alters the chemistry of the soil to kill other seeds, creating a monoculture. Asian bittersweet – this vine can kill or damage trees and shrubs. Crown vetch – alters the soil chemistry and pushes out the variety of other plants. Japanese knotweed – tolerates floods and drought, creates a monoculture. Spotted knapweed – releases toxins into the soil to poison its competition. Common reed – this introduced non-native species aggressively pushes the native species and other aquatic plants out of the ecosystem. Canada thistle – out-competes native vegetation in prairies, savannas, and dunes.

Species established within the Dunes

Current threats Acer platanoides - Norway maple Ailanthus altissima - tree of heaven Alliaria petiolata - garlic mustard Artemisia vulgaris - mugwort Berberis thunbergii - Japanese barberry Celastrus orbiculatus - Oriental bittersweet Centaurea maculosa - spotted knapweed Cirsium arvense - Canada thistle Cirsium vulgare - bull thistle Elaeagnus angustifolia - Russian olive Elaeagnus umbellata - autumn olive Euonymus atropurpureus - burning bush Helianthus petiolaris - petioled sunflower Hesperis matronalis - dame's rocket Holcus lanatus - Yorkshire Fog, velvet grass Leymus arenarius - lyme grass Lonicera tatarica - Tartarian honeysuckle Lonicera hybrids - Hybrid honeysuckles Lonicera japonica - Japanese honeysuckle Lonicera maackii - Amur honeysuckle Lysimachia nummularia - moneywort Lythrum salicaria - purple loosestrife Melilotus officinalis - yellow sweet clover Phalaris arundinacea - reed canary grass Phragmites australis - common reed, phragmites Reynoutria japonica (syn. Polygonum cuspidatum) - Japanese knotweed Rhamnus cathartica - common buckthorn Rhamnus frangula - glossy buckthorn Robinia pseudoacacia - black locust Rosa multiflora - multiflora rose Typha angustifolia - narrow-leaved cattail Typha × glauca - hybrid cattail

Emerging threats to natural resources or extent unknown Alnus glutinosa - European alder Carduus nutans - musk thistle Coronilla varia - crown vetch Cynoglossum officinale - houndstongue Dipsacus sylvestris - common teasel Euphorbia cyparissias - cypress spurge Euphorbia esula - leafy spurge Gypsophila paniculata - common baby's breath Humulus japonicus - Japanese hops Iris pseudacorus - yellow iris Leonurus cardiaca - motherwort Ligustrum vulgare - common privet Morus alba - white mulberry Myriophyllum spicatum - Eurasian watermilfoil Pinus sylvestris - Scots pine Populus alba - white poplar Populus nigra - Lombardy poplar Robinia hispida - bristly locust Saponaria officinalis - bouncing bet Ulmus pumila - Siberian elm Vinca minor - periwinkle Viburnum opulus var. opulus - European cranberry bush

References