Microstegium vimineum (Japanese stiltgrass) - Photo Credit: Tom Potterfield (CC BY-NC-SA 2.0)

Non-native invasive species (NNIS) are a growing problem (no pun intended!) in West Virginia and at Canaan Valley National Wildlife Refuge. Several of the biggest problem species at Canaan Valley include Japanese stiltgrass (Microstegium vimineum), autumn olive (Elaeagnus umbellata), and multiflora rose (Rosa multiflora) which have taken a foothold along the outskirts of the refuge and within the core of the refuge along some of the more heavily trafficked trails and roads.

Invasive plants outcompete native plant species in a variety of different ways. Japanese stiltgrass, for instance, can grow up to a meter tall, shading native plants and trees, and after it dies, may form a thick layer of vegetation that is slow to decompose. Just one plant may produce between 100 to 1000 seeds, each one capable of starting a whole new population of stiltgrass if carried to a new uninfested site. Autumn olive, on the other hand, a shrub capable of producing 10’s of thousands of individual seeds, has the ability to fix nitrogen giving it a competitive advantage against many native plant species, especially in disturbed nutrient poor environments. Birds are attracted by its bright red berries and consume them (and spread them) in abundance.

Canaan Valley Refuge is serious about our invasive plant infestations. This year we employed a coordinated effort to treat sites that had been previously treated in past years and to work with local landowners to treat on private lands that are adjacent to the Refuge. Additionally, refuge staff focused on treating sites that harbor known threatened and endangered species to protect them from the suppressive nature of these invasive species and also treated heavily traveled corridors that might facilitate their spread.

We have great expectations and big plans for next year’s invasive species treatments. We purchased an assortment of impressive tools to mechanically treat the shrubby invasive plant infestations. With these new tools, we can accommodate at least 30 additional volunteers in the field and treat larger regions of the refuge in a shorter period of time. Moreover, we have at least two additional staff that will be certified to apply herbicides to tackle the various non-natives that threaten the flora and fauna of the Canaan Valley.