Plan Now, Benefit Later:
Invasive Species Best Management Practices – Part 1
Invasive species cost the U.S. over $138 billion per year and that approximately 9% of forest products, worth a total of $7 billion per year, are lost as the direct result of non-native plant pathogens. If we look at the environmental impacts it is estimated that 42% of threatened or endangered species are classified “at risk” due directly to non-native invasive species. The detriment of invasive plant species doesn’t stop at economics or the environment. Plants like wild parsnip (Pastinaca sativa) and giant hogweed (Heracleum m2antegazzianum) can both cause burning and blistering of the skin if the oils or sap of the plants get on skin that is exposed to UV light.
Due to these issues, natural resource professionals have developed four tenets of management for invasive species: prevention, early detection, eradication, and lastly, control. The first step to addressing invasive species is taking steps to prevent the introduction of new invasive species if at all possible. Unfortunately, by the time we are aware of the problem, it is often too late for overall eradication and our only course of action is selective control and management on a smaller scale. Once widespread eradication of the invasive species is not feasible we can turn to best management practices or BMPs for guidance as to how to reduce the spread and manage the problem species.
The Indiana Invasive Species Council has a working group called the Invasive Plant Advisory Committee (www.entm.purdue.edu/iisc/plantcommittee.php) that has put together a Top Ten List of Invasive Species Best Management Practices. This list can help woodland owners and land managers make good decisions limiting the introduction and spread of problem species. It is unlikely all ten will be able to be implemented at once but it is a goal to work towards. Choose the easiest of these to implement first and work from there.
1. Develop an invasive species strategy that is site specific. Determine what your goals, priorities, and the tactics that are at your disposal or can be used are.
2. Give yourself an invasive species knowledge base.
Firstly, it is important to know and understand the lifecycle of invasive plant species present on your land.
• Is it a perennial, biennial, or annual?
• How does it reproduce or spread?
• When does it go to seed?
• When is the best time to control it and how should I do it?
Know where your infestations of different species are. Map them and encourage family, staff, or other users to report them. Document your control projects: include what you did, dates, locations, what you used (if herbicide, list the concentration), weather and soil conditions, asses your results both after treatment and then later after additional growing seasons.
3. Think ahead, pre-plan before making major changes to the land or to maintenance.
Always try to avoid disturbing heavily infested areas when possible. Pre-treat these areas well before the disturbance is set to take place. If possible, conduct activities (mowing, timber harvests, etc,) when the invasive plant seeds are not present and can be spread. An example would be mowing Japanese stilt grass when it is setting seed. The seeds get lodged in the tire treads and other parts of the mower and are subsequently spread to new areas. Whenever possible, use already existing roads, trails, landings, and staging areas to reduce site disturbance.
4. Use plants and plant seeds native to Indiana, make sure they are from “weed free” sources
Use plant species that will do well on the site and conditions. Check to be sure species received are what was requested and ask for guarantees and or make good provisions in sourcing contracts. Use “trusted sources” whenever possible for re-vegetation projects on landings or other disturbed areas.
5. Use uncontaminated construction construction/landscaping material (gravel, fill, straw, mulch etc,)
Find certified or guaranteed sources where possible and ask for guarantees or make-good provisions in sourcing contracts. One option is creating an on-site source. It is always a good idea to monitor stock piles regularly.
Alexandra Wardwell is the Project Director of Southern Indiana Cooperative Invasives Management or SICIM. SICIM is a non-profit cooperative weed management area that covers 35 counties in southern Indiana. For more information about SICIM please visit our website www.sicim.info.