TOSSI – Weeding the wilderness

The people of Aotearoa are embracing the goal to eradicate four-legged predators from our land but when it comes to green pests – we’re not so enthusiastic. Weeds, shrubs, trees and climbers have escaped from our gardens, and hitched a ride into the wilderness on the wind, water, our socks or via bird poop. Unfortunately, removing weeds just isn’t as exciting as trapping a rat. But opportunist plants take advantage of freshly revealed patches of light, slips and windblown dirt to get a grip on the earth before our indigenous flora can get a look in.

When I started volunteering at Tāwharanui, experienced environmentalists took me on a hunt for invasive weeds. I discovered that a weird plant I had been observing in my own backyard was woolly nightshade – a nasty weed I was about to spend a morning hacking out of the bush. Tossi volunteers work with Auckland Council to plan the removal and prevent reinfestation of such unwelcome green inhabitants, while I was unwittingly nurturing the stuff. Clearly, I needed to learn more about problem plants.

The goal at the open sanctuary isn’t to produce a pristine botanic garden but rather, to create a habitat where indigenous plants can regenerate. New Zealand’s native flora produces the ideal sustenance for native fauna, and the unique plants enhance the success of rebuilding balanced ecosystems.

Year-round, Tossi volunteers scramble through the forests of Tāwharanui hunting for dreaded woolly nightshade and scouring cliff faces to locate boneseed plants. Both were introduced to Aotearoa as garden plants, and when they become naturalised, they put pressure on the biodiversity of New Zealand. They produce berries that are poisonous to us and animals, but kererū and other birds can eat, and consequently excrete them throughout the wilderness. Seeds can remain dormant for decades, and when they do germinate many pest plants are allelopathic, that is, they create toxins in the soil, which prevent other plants from growing.

The removal of problem plants is a never-ending task for volunteers, but it is rewarding. Since learning about invasive weeds, it makes my eyes water when I spot them thriving along roadsides, throughout reserves and along Kawau Bay’s coastline. Weeds should be the next big thing for conservationists.
Last November, the Parliamentary Commissioner for the Environment, Simon Upton, released a report, Space Invaders: A review of how New Zealand manages weeds that threaten native ecosystems. The Commissioner recommended ways to improve the management of invasive weeds in New Zealand and called for improved national leadership to coordinate action.

While the powers that be discuss strategies, actions we can take are – check the weed status of plants before buying them from garden centres and stop sharing them with neighbours or chucking them onto seemingly unoccupied land. There are also plenty of weed eradicating opportunities with Tossi at Tāwharanui and other groups around the region.