Background
In 2017 the Department of Conservation made available funding for community groups to undertake local weed control. SIRCET was successful in receiving funds and partnered with Environment Southland to deliver the work. The fourth year of SIRCET weeds control commenced on the 7th of September 2020. Darwin’s Barberry was the main target but other weeds such as Bomarea, Spanish Heath, Buddleia, Pampas and Gunnera tinctoria were also of interest.
Darwin’s Barberry
Originally from South America, this weed was likely introduced to Stewart Island as a good hedging plant. Its rapid growth and prickly leaves make it ideal for this. Plants mature in three to four years and produce many seeds that are dispersed widely by birds. With its ability to grow rapidly, a liking for our weather conditions and being able to thrive in the bush it poses a serious threat to the integrity of our native forest. For more info: https://www.weedbusters.org.nz/weed-information/weed-list/darwins-barberry/
The Job
the most effective method to control Darwin’s Barberry is to grid search with a team of people and control every single Barberry plant. Each person carries a GPS so we can track exactly where they walked and mark every plant they control . Every landowner has to be contacted and permission sought to access their land. Any areas left unsearched will potentially result in Barberry plants still being left to spread seeds.
Results
2020 - 113 Hectares were controlled between Sept-Nov 2020, the team removed 445 adult plants and 26,027 juvenile plants See Map
2019 - 124 Hectares were completed over two and half months, the team removed 1,386 adult plants and 7,987 juvenile plants - See Map
2018 - 87 Hectares were grid searched over two months and the team removed 937 adult plants and 10,262 juvenile plants - See Map
2017: 80 Hectares were grid searched over two months - See Map
Follow up to prevent Barberry gaining a hold again is needed beyond the War on Weeds project.
The Restoring Rakiura project’s work to remove invasive weeds provides continuity of the efforts, and this paired with assistance from locals and landowners to please remove Barberry when they see it will help prevent reinvasion.
