Controlling Impatiens edgeworthii in Germany
Impatiens edgeworthii (Balsaminaceae) is an annual species native to the Western Himalayas where it is found in high altitude valleys in India, Nepal and Pakistan. It is currently spreading in East-Central Germany where it grows in forests and extends along tracks and forest edges. I. edgeworthii was listed on the EPPO Alert List from 2015 until its transfer to the EPPO Observation List in 2018. Based on its potential to negatively impact native plants, botanists in the (voluntary) Botanical Society of Berlin and Brandenburg (BVBB) tested the potential for Early Detection and Rapid Response (EDRR). Even though EDRR is often promoted as the second-best option to deal with invasive species (after prevention), there is relatively little information on the effectiveness of this method for invasive alien plants as shown by a literature review. It seems therefore unclear if, and to what extent, the ongoing invasion of a new species can be stopped or slowed. Activities of the BVBB included targeting one population of the species per year in Berlin where all the individuals of I. edgeworthii were pulled before they produced seed. All plants were measured and counted, and the surrounding vegetation was recorded. Plots are revisited in following years to record the presence/absence of I. edgeworthii. So far, one population has been successfully eradicated, though for another population this was not successful, so the measure had to be repeated. The work is ongoing.
Sources
Starfinger U, Burkart M (2021) Verfälschung oder Bereicherung? Die AG Neophyten des botanischen Vereins und Impatiens edgeworthii. Verhandlungen des Botanischen Vereins von Berlin und Brandenburg 152, 281-284.
Starfinger U, Burkart M (2021) Lässt sich die Invasion einer Pflanzenart aufhalten? ‘Early Detection and Rapid Response’ am Beispiel von Impatiens edgeworthii, dem Bunten Springkraut, in Berlin und Brandenburg*. Verhandlungen des Botanischen Vereins von Berlin und Brandenburg 152, 105-114