Fire and Invasive Species

Some invasive species are susceptible to fire while others are not. In Nebraska, and in my back yard, Russian olive trees (Eleagnus angustifolia) are listed as invasive species. Russian olive trees are a very hardy tree which is known to choke out other local plant life due to its love of water. This species is only known to be controlled here through mechanical means and fire is not effective because of its ability to re-sprout after being burned. Fire is used as a suppression technique for spread instead of eliminating established trees (Field Guide for Managing Russian Olive in the Southwest, 2014.) Even with mechanical methods this tree grows back quickly and effectively.

Russian Olive trees invade a riparian ecology

                                                                 (Friedman, 2016)

One invasive species which is partially controlled by fire in Nebraska through is Canadian thistle (Cirsium arvense). Canadian thistle is a creeping root plant which emits toxins to compete with native vegetation ("Canada thistle species page", 2016.) Contradictory to its name Canadian thistle is from Europe and was introduced by settlers in 17^th century ("Invasion Biology Introduced Species Summary Project - ColumbiaUniversity", 2004.) Fire alone is not enough to control the spread of this invasive species and complex and intensive methods combining chemical, mechanical, and biological tactics have shown to work. Fire in early spring may increase the spread of this invasive species by encouraging sprouting and reproduction, therefore late spring burns are required.  Normal fire regimes of the Great Plains grasslands have failed to effectively control this species, which is why it is considered an invasive species.

                                           ("Nebraska Weed Control Association", 2016)

References:

Canada thistle species page. (2016). Nematode.unl.edu. Retrieved 26 May 2016, from http://nematode.unl.edu/cthistle.htm

Field Guide for Managing Russian Olive in the Southwest. (2014) (1st ed., p. 4). Retrieved from http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5410126.pdf

Friedman, J. (2016). tamarisk (Tamarix spp) | Fort Collins Science Center. Fort.usgs.gov. Retrieved 26 May 2016, from https://www.fort.usgs.gov/thesaurus-topic/tamarisk-tamarix-spp

Invasion Biology Introduced Species Summary Project - ColumbiaUniversity. (2004). Columbia.edu. Retrieved 26 May 2016, from http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Cirsium%2520arvense%2520.html

Nebraska Weed Control Association. (2016). Neweed.org. Retrieved 26 May 2016, from http://www.neweed.org/weeds.aspx