Asian carp are a serious concern because they compete with native fish and can injure boaters when they jump out of the water.
Slow the spread by hand and tread
June is Invasive Species Awareness Month in Wisconsin.
From Eurasian watermilfoil and Asian carp, to emerald ash borer and gypsy moth, the state is under attack from all directions. These invasive species cause serious damage not only to the ecology but to environmentally dependent industries such as timber, fishing and tourism.
Those who live, work or play in Wisconsin can, and should, play a vital role in slowing, stopping and preventing invasive species in this state.
As a response to the increase of invasive species in Wisconsin, the Department of Natural Resources in 2009 created Chapter NR40 in the administrative rules to teach people how to identify invasive species as well as ways to prevent their spread. The rule allows the department to take quicker action against a potential or known invader, as well as to ensure that any actions are consistent.
What are invasive species?
Invasive species are non-native species that are introduced, often by human activity, into an area and cause damage to that area’s ecosystems.
But not all introduced species evolve into ecosystem destructors. In fact, in most cases the introduced species has little, if any, impact on its introduced area and, in some cases, non-native species actually benefit some ecosystems.
It seems that almost everyone in a typical neighborhood has Japanese somethingor- others, or a Colorado pine of some sort in their yards, but we do not see these taking over the Wisconsin landscape. Nonnative plants cannot be all that bad then, right? Wrong.
Introducing non-native species can have unpredictable results on the surrounding ecology. There are many factors involved for a non-native species to move from being just an introduced species to becoming an invasive species.
Non-natives tend to lack natural predators in a new area. How do these species fair in Wisconsin winters? Can they thrive in the sandy soil of northern Wisconsin, or in the clay-based soils of southern Wisconsin? Will local bees pollinate introduced flowering plants, and how do the seeds and seedlings germinate?
These are just a few of the questions that factor into an introduced species’ ability to become invasive.
What can we do?
Landowners, those who lease land, or those who work or play on Wisconsin lands can help the Department of Natural Resources and other agencies take a stand against the spread of invasive species.
Be on the watch. According to the Department of Natural Resources there are over 70 NR40-regulated plants currently on the loose in the state, not to mention a large number of insects and animals. A full list of these can be found at the DNR’s website. Visit Wisconsin Department of Natural Resources and search “invasive species.”
Preventative steps and invasive species identification are the first and perhaps most important steps in attacking invasive species in Wisconsin. Your ability to identify and properly report an invader is vital to tracking and removing invasives. Reporting the invader(s) allows the Department of Natural Resources to track where an invasive species may be moving, as well as to determine a best course of action to eradicate the invader.
According to the Department of Natural Resources there are five best practices for landowners and land users to be aware of: prevention, early detection and rapid response, control, monitoring and restoration.
Prevention is the safest and easiest way to ensure that an area remains invasive free. Here are some tips:
Early detection and rapid response
Early detection means a rapid response can be mounted, saving both you and the Department of Natural Resources many hours of labor and preventing undue ecological and financial strains.
Familiarize yourself with the invasive species already present in the state. Also, it is important to remain up-to-date on newly identified invasive species by frequently checking the department’s invasive species Web page, especially in the late spring and early summer months, as this is the time most invasive plants begin to flower or seed. If you come across an invader, report your sighting by calling your nearest DNR office or by following the steps on their website.
This way, the Department of Natural Resources will be able to formulate the best course of action not only for your property but for any of the surrounding properties, whether they are public or private.
Containment and removal
So you have found an invader on your land. Now what? In most cases you will begin by using a combined prevention and control method called integrated pest management (IPM). This means using destructive methods on the invaders while performing preventative measures in the affected area and surrounding areas.
Completely removing the invader is possible, especially if the invader is discovered early in its establishment. However, once the invader is widely established the best course of action is usually to control the pest in a way that reduces its density to the point of becoming balanced with the surrounding native species.
There are several methods to contain or remove invading species.
First on the to-do list is to slow and prevent further spread of the invader. How to do this depends on the nature of the invader (plant, tree, insect, mammal, etc.).
For plants, cut or mow the area frequently during the height of the invaders’ growing season while making sure you fully clean any equipment used before using it in another area. Hand pulling an invasive plant can be effective, but when doing so make sure you are getting the entire root system. Smothering plants is especially effective against low-lying plants and should be done using mulch or other environmental landscaping plastic for at least one full growing season.
If available and allowed by local ordinances, you can use a grazing animal to eat the invader. An appropriate herbicide can lend a helping hand for the especially tough invader that does not appear fazed by any of the previously mentioned methods.
For trees, consider girdling, which is the process of removing bark in a ring around the tree and then applying herbicide to the removed area. A controlled burn is especially effective, but is probably best left to an expert.
Controlling invasive insects mainly requires the use of pesticides or unleashing native predators.
Trapping may be in order for mammals or reptiles, but this technique should be handled by a professional so the effects have a minimal impact on native species.
These are only some examples of the many methods used to contain or remove an invasive species. A complete list of the methods available as well as herbicide recommendations and species timing cycles may be found on the DNR website.
One last thing to remember is that any invasive plants or trees that are removed should be disposed of in a landfill. Thanks to the DNR’s enforcement abilities, local landfills must accept these plants. Place them in clear plastic bags, label them “invasive plants; approved by WI DNR for landfilling,” and dispose of them according to your local landfill regulations.
As your containment and removal activities come to a close, having a good monitoring strategy in place can help reduce the likelihood of an invasive’s return. Regularly check previously infected areas and the surrounding areas early in the spring through the end of the invader’s growing season (or mating season for non-plants). Check that no new invaders have taken up residence.
Restoring invader-affected areas on your property is an important step as it restores vitality and balance to your property’s ecosystem. Following the DNR best practice guidelines also helps prevent re-establishment. The easiest and most effective method is to plant (or release in the case of non-plant invasions) as many species native to your area as you can while maintaining a competitive balance among them.
A team effort
Those of us who live, work and play in Wisconsin serve an important role in the battle against invasive species. Whether we contribute by securing our own properties, volunteering to pull garlic mustard plants at one of our great state parks or by alerting local authorities to a newly found patch of wild parsnip, we can all work together and turn the invaders back.
Cary Kostka has participated in various invasive plant cleanup programs in southeastern Wisconsin.