Non-native invasive plants threaten the natural diversity and beauty of northern Michigan. Treating invasive species gets prohibitively costly as an infestation grows, that is why vigilance is recommended to detect infestations early. Managing invasive plant species requires an ability to identify invasive plants, develop a management plan, and have an understanding of treatment/control best practices.
What is an invasive plant?
Invasive plants are those that out-compete the plants found in native habitats and cause a decrease in habitat quality. They are generally non-native (exotic) plants that have evolved in a different part of the world and lack the natural predators and diseases that would control them. Not every non-native plant is invasive. Only a small percentage of non-natives (of which there are thousands!) are easily transported and spread aggressively; these are the species identified as invasive plants. In addition, a few native plants that can spread aggressively to decrease habitat quality will make it on lists of invasive species.
Why should we be concerned about invasive plants?
Invasive plants have the ability to take over native plant communities, forming monocultures and displacing native plants. When a site is overrun with one or more invasive species there is a decrease in biodiversity. Diversity gives natural systems resilience to pest outbreaks, rapid environmental stresses, and effects from fragmentation and other human induced changes. We depend on natural systems for food, fibers, medicines, maintaining and filtering water supplies, protecting shorelines and more; when these systems are jeopardized, so too are the services they provide.
Native plant diversity is also important for wildlife habitat as many animals depend on a variety of native plants for food and cover. Invertebrates who feed on plants are critical to the survival of many birds, amphibians, and reptiles. Even the birds that we think of as berry or seed eaters depend on insects when they are feeding their young because most fruits aren’t available until late summer! And research shows that native plants “produce” many more insects than non-native species.
Invasive Species Management
A landowner can learn about invasive species management on their own or they can hire and collaborate with a biological consultant experienced in managing invasive species. Visit the ‘resources page’ to find a professional. The resources and information below will provide you with a foundation for learning how to control the invasive species on your property. We occasionally offer training events as part of our Eco-Stewards program and we also encourage you to join a LTC staff member during the annual monitoring of your easement property—they may be able to point of some invasive species!
Plant identification takes time and practice. Several factors make plant ID daunting: the sheer number of plants, the fact that many plants look alike if you don’t catch them at the right time with a fruit or flower, and field guides that are either very technical or too basic not covering enough species. Start by learning just a few, like the invasives in your region and some of their look-a-like native species. Memorize, or bring with you, the key characters from each organ (roots, stems, and leaves/flowers) so you can have something to examine any point of the season. Landowners have the convenience of being able to “watch” a plant throughout a growing season. It may take observing several features over time before you can confidently ID a plant. Eventually, the plant will be committed to memory. Also learn how to use keys in more advanced field guides that will distinguish similar looking plants. Botanists have developed a plethora of terms to describe various characters and forms and it can get over whelming, but you don’t have to memorize it all—you can bring a glossary with your field guide!
Here is a good online module to learn some common invasive species: MISIN Training
A pocket field guide of Michigan invasive plants is available for download at this site, but you should consider ordering a hard copy.
Here is another guide for identifying some invasives (although this has several that aren’t applicable to our area).
Other field guides for the Midwest are available here.
You need to know where the infestations occur. How many are there? Where? Are the infestation all in one area or spread out? Which species are present and how big of a threat do they pose for the habitats on your property? Answering these questions requires a survey of your property. It often helps to make a map of your property and take it with you to mark up with your observations. Using a GPS to mark the locations and adding them to a digital map is even better (see this example). Many of the professionals listed on the resources page can help with this, or contact us.
3. Develop a Plan
The information from your inventory is crucial to planning your management strategy. Unfortunately several species, such as spotted knapweed or honeysuckles, are so prevalent that complete elimination is not a realistic goal. This is very site specific though, some properties or property owners with the resources and desire may be able to eliminate later-in-the-stage infestations. This is why a plan is important. You need to identify what your priorities and goals are for your property. From your inventory, which species could be classified as early stage, meaning the infestation was small and not too widespread? Mid-stage? Or late stage, where it would cost a lot of money and maybe several years before the species could be completely eliminated? You need to evaluate your resources and maybe some species you’ll have to let go, or just try and control from spreading further, or just eliminate from a sensitive area like a wetland. Having a written plan will enable your efforts to be effective and efficient and are often necessary for cost-share programs.
4. Take Action
Following the plan you’ve outlined take action to eliminate, reduce, or control invasive plant infestations. Each species may require different treatment protocols. Timing: what time of year? Method: hand-pulling, cutting/digging, or are herbicides required? Concentrations: If herbicides are required, how much, what kind, and how and where do you apply it? Some herbicides require special licences to purchase or apply. In many situations, herbicides sold at local stores, if at the appropriate concentration can do the job. Please read all labels and FOLLOW their safety and application instructions. Again, there are trained and experienced consultants to help with application of herbicides. Look for some best practices protocols for specific species to be provided below.
5. Continue to Learn and Monitor
Successful invasive species management requires regular and continued monitoring. Follow-up on treatments and know that new infestations can come into your property each year via birds, air, water, or your boots. Proactively plant native species and keep identifying new plants on your property, it is a lifetime sport.
What is LTC doing?
LTC’s stewardship staff is responsible for 15,000+ acres and has adopted Early Detection Rapid Response protocol (EDRR) for dealing with invasive species. When we choose to allocate resources to manage invasives it is for infestations of high priority species and sizes that can be eliminated without exorbitant costs. We will also prioritize by the sensitive habitats, the preserve, and whether we have local support at a site. Right now, we know too little, and are seeking volunteers to help us fill in the information gap. If you would like to survey a preserve for invasive species, we’d love your help. Please visit the Eco-Steward program for more information!