Invasive species are those plants, animals and disease organisms that are not native to a region, yet when introduced, can cause significant harm. The term is generally used for those species that cause ecological harm to our native fish, wildlife, plants, lakes, forests and other natural areas. Many species are weedy or pests in agricultural areas, but not in wild lands. Conversely, many of the invasive plants and animals affect only wild areas species, and do not harm crops or livestock. However, there are a number of species such as Canada thistle that do double duty. It is important for persons involved with agriculture to know about invasive species, as they can be both the victims of this harm, and may unwittingly introduce or spread invasive species.
There are a number of factors that are causing a rapid increase in the number of species invading Wisconsin. These include rapidly growing global trade, the public’s insatiable desire for new landscaping plants and global climate change. In addition, those invaders already in the area are accidentally moved around by roadside mowing, logging and farm equipment, tourists and outdoor recreationalists. The majority of people introducing or spreading these harmful species around are unaware of the harm they are causing. Many efforts have been underway for a number of years to raise the public’s awareness of the species of concern and what they can do to minimize their spread. Outreach efforts alone have not been sufficient to stem the tide of these invaders. Over the last few years groups of foresters, right-of-way managers, recreation enthusiasts and landscape industry members have been working together to create a series of voluntary Best Management Practices to help people in their fields to minimize the accidental spread of invasives. Agriculture is another large area of the economy that may benefit from developing similar voluntary practices.