Fire and the management of invasive species

According to the National Invasive Species Council (2016), an invasive species can be defined as:

-non-native to the ecosystem under consideration
-whose introduction causes or is likely to cause environmental or economic harm or harm to human health

Invasive species are typically difficult to control, resilient to treatments, highly competitive, and can spread easily. Fire, as well as numerous other management efforts, can be utilized to manage invasive species. 

Prescribed burns can rid some invasive species and encourage the re-emergence of native species. Native seed germination and dispersal can occur after prescribed burns and soil conditions can return to favorable conditions for native plants (versus that of non-native).

However, some fire regimes may not completely rid invasive species, and re-application may need to occur for an additionally 2-3 years. In addition, herbicides or pulling may also need to be utilized in order to completely rid the species.

Invasive species such as cheatgrass can completely alter fire regimes, and prescribed burning on this non-native plant can actually have reversed effects. Post-fire, cheatgrass will return quickly and dominate the landscape more than it did prior to the burn (BLM 2013). Because of this, examination of the dominant species in the landscape needs to occur prior to the application of fire. While some invasives can be wiped out from fire, many thrive post-burn, creating an even higher level of difficulty for land managers.

Sources:
BLM. 2013. Invasive species alter fire regimes and fire operations. Available from http://www.blm.gov/wo/st/en/info/history/sidebars/fire/invasive_species_alter.html

National Invasive Species Council. 2016. FAQ. Available from https://www.doi.gov/invasivespecies/faqs#what_is