Six ways to prevent the spread of invasive plant species
Insights from an environmental practitioner,
As environmental practitioners, we have respect for ecological communities and feel a responsibility to protect them. By implementing some basic best management practices into our daily work routines, we can make big changes in our environment and stop the spread of non-native invasive species.
Environmental practitioners visit a multitude of different sites for field work in a single growing season. These sites vary from conservation areas or nature preserves with pristine ecological conditions to sites where historic industrial activities have greatly impacted the habitats. Often, scheduling calls for visits to multiple sites that cover this spectrum within one weeks’ time. We have a single pair of boots used at each of these sites and, as a field biologist who mainly deals with aquatic environments, I have a pair of Muck boots for these visits. I could visit hundreds of sites during their life span.
This has led to some recent thoughts about the lack of decontamination within our practice.
As part of my field duties, I manage and monitor a wetland mitigation bank in Northern Kentucky. My duties consist of biannual wetland habitat characterization, precipitation and hydrology assessment, and non-native invasive plant species management, through herbicide application. Within the last two years, I observed and began treating hairy jointgrass (Arthraxon hispidus), a low-growing creeping annual grass that prefers moist areas, like wetlands, and is listed as a Kentucky Exotic Pest Plant Council Severe Threat species (Bender et al. 2013).
The hairy jointgrass was originally observed within one monitoring location. Following the initial fall treatment, I began flagging other occurrences of hairy jointgrass, and it became apparent that new populations were concentrated along the undeveloped paths; all the occurrences were near or spreading from paths that I was using to access different areas of the site. The hypothesis I formed was that I was the culprit of this spread. This observation is an example of an individual spreading non-native invasive species from one location to another by completing tasks needed for monitoring.
Speaking from personal experience, little attention is paid to what we, as practitioners, may be introducing to the habitats we visit during field reconnaissance. Due to this lack of decontamination, we could inadvertently introduce a non-native highly-invasive species to other portions of a site, or to another site.
The outreach campaign, PlayCleanGo: Stop Invasive Species in Your Tracks®, partially funded by the USDA Forest Service and the Minnesota Department of Natural Resources (MNDNR), offers some great tips to those working in the field (PlayCleanGo 2018). PlayCleanGo suggests that by following these simple steps, you can prevent the spread of non-native invasive species and protect the environment:
- Come Clean. Before leaving the shop, take a little time to inspect your gear and remove dirt, plants, and seeds from clothing, boots, gear, and vehicles.
- Use weed-free materials. When bringing soil, gravel, or other material onto a work site, check your sources to make sure they are weed-free. Where the only available sources are known to be infested with invasive plants, scrape off the top 6 inches of material and set aside. Then use the newly exposed material for the project at hand.
- Burn or utilize wood waste. Pallets, packing material, and containers made from untreated wood can harbor plant pests. Plan ahead to either burn or utilize wood waste. One option is chipping the wood and selling it as biofuel.
- Stay in designated areas. Check with the project manager to identify designated areas for parking and areas for storing supplies and equipment. Then stay within those designated areas.
- Start at the cleanest site. When mowing, grading, or doing other work that involves moving from site to site, plan your work so that you start at the least infested site and finish at the most infested site. Between sites, use a brush or hand tool to remove accumulations of mud and plant debris.
- Leave clean. Before heading back to the shop, inspect your vehicle and gear. When available, use a power washer or air compressor to remove any dirt, plants, seeds, or bugs. When these are not available, use a brush or other hand tool to knock off dirt clods and plant debris (PlayCleanGo 2018).
Furthermore, to decrease the likelihood of spreading non-native invasive species on the job, I offer some best management practices to incorporate into our routine field work operations. These may include:
- Purchasing a dedicated pair of boots for specific projects. This dedicated pair of boots should be worn only for field activities specific to the project for which they were purchased. This can be a safeguard for highly-sensitive areas (i.e., areas that exhibit no non-native invasive species, or areas with species that are biologically valuable) and prevent the introduction of non-native invasive species in the first place.
- If purchasing dedicated boots for specific projects is too pricey, consider over boots or boot covers.
- When purchasing dedicated boots or over boots is not an option, decontaminate all visible vegetation and soil from footwear and clothing prior to leaving a site. Use a boot brush and an adhesive roller in the field to remove seed material from boot fabric and clothing.
- Some seeds readily adhere to, and can be difficult to remove from, clothing and safety vests, so disposal of that safety vest or clothing may be advisable if the species is non-native invasive.
- Successful implementation requires availability of decontamination equipment to field staff, such that decontamination can be completed prior to leaving the site, thereby preventing the spread of the non-native invasive plant as a result of our movements. A great way to do this is to make a grab-and-go plant decontamination kit with the supplies outlined above as part of your site reconnaissance field equipment.
- If decontamination activities in situ is not an option, due to lack of equipment or hazards, inspection and removal should be completed as soon as possible and prior to visiting another site. Creating a designated decontamination area at the office would be ideal, complete with boot brushes and a source of water for deep cleaning of boots, as applicable.
About Tara Sturgill: Tara is a scientist at OBG specializing in stream and wetland delineation, 404/401 permitting services, ecological site assessment, invasive species management, habitat monitoring, habitat restoration, and geographic information systems (GIS). She provides innovative solutions to solve complex challenges through designs, evaluations, and reports that are practical, feasible, and responsive. Tara is a certified wetland delineator and a State of Kentucky certified pesticide operator. She serves on the Executive Committee of the Northern Kentucky Urban & Community Forestry Council and is a member of the Society of Wetland Scientists.
Tara can be contacted at Tara.Sturgill@obg.com.
Bender, J. et al. 2013. Exotic Invasive Plants of Kentucky. Third Edition. Kentucky Exotic Pest Plants Council. Available at: https://www.se-eppc.org/ky/
PlayCleanGo 2018. Website content available at: http://www.playcleango.org/