Invasives

Invasive Species

Invasive plant species are responsible for more than 30 billion dollars in damages and control costs in the US each year. Indiana’s total is estimated at between 5 and 6 billion dollars. These totals continue to rise as non native plants continue to take over more area.

Invasive plants are defined as non native plants that have become naturalized in our environment and are replacing native plants. A non native plant is one from another country being imported usually for a perceived beneficial purpose. They cause both economic and environmental damage. Economic damage is generally said to be loss of agricultural and forestry production as well as costs incurred in controlling these plants. Environmental damages include loss of native plants, damage to songbirds and pollinator insects, spread of plant diseases like black stem rust in small grains, destruction of songbirds and many other unknown damages.

Since songbirds, insects and other forms of our animal kingdom did not evolve with the invasive plants they are not accustomed to living with them. A good example relates to insects and songbirds. Songbirds rely on insects and insect larvae for high protein and fat foods necessary for food not only for themselves but for their young. Most insects do not live or reproduce on invasive plants because of the evolution concern, therefore as invasive plants increase, insect populations and food for songbirds decreases.

Several of the invasive plants exude a chemical into the soil that prevents or severely reduces the germination of native plant seeds. This is one of their ways to increase their takeover of natural areas. Invasive plants like Asian Bush Honeysuckle, Autumn Olive, Multiflora Rose and Japanese Stiltgrass shade the soil surface reducing the germination of native wildflower and other plant seeds. Many of these plants are also unpalatable for deer and other wildlife, causing the wildlife to graze and damage young trees for future timber production.

Control of these plants is not a major undertaking unless an area is heavily infested but it does take commitment and usually is not a one shot affair. Many can be pulled when the soil is moist and the plants are relatively small. Systemic herbicides are effective when sprayed on either the foliage or when the stems are cut and sprayed. When Garlic Mustard is the problem weed being pulled the plant should be put in a plastic garbage bag and disposed of in a land fill or incinerator.

The Indiana State General Assembly has recently established the Indiana Invasive Species Council to not only work on the invasive plant concern but also other invasive species such as the Emerald Ash Borer, Asian Carp, Zebra Mussels and other species damaging Indiana ecosystems.

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