Replacing weeds with rare plants
Ö.was the aim of the weedbusters stand at the 2007 Murchison A&P show.
Specimens of two local Murchison plant species threatened with extinction were being offered to locals bringing weed specimens from their homes, on the promise that they would kill the weed and plant the rare plant in its place. The rare plants were leafless mahoe (Melicytus flexuosus), and bloodwood (Coprosma wallii).
The valleys of the Murchison district provide a stronghold for several species of native tree and shrub that are nationally rare, and even here they are threatened with extinction through weed encroachment and pasture development. Adult trees that still remain after many decades of farming are at risk of being cleared during pasture development, and in the places that arenít grazed the seedlings of these species canít cope with the competition from aggressive weedy species such as willows, blackberry, hawthorn and sycamore. The threatened species are found growing in patches of scrub or open forest on alluvial flats that are particularly frosty during the winter. Botanists call these places frost flats, and the semi-deciduous, open forest type that these places naturally support is now almost extinct.
The hope is that we can help reverse the plight of these species by getting them into local gardens which will improve the availability of seed in the local environment. If we can reduce the dominance of weeds in the area at the same time itís a win-win situation. Both plants are good for gardens - bloodwood grows into a small shade-tree shape and as an adult will provide a good food source for native birds. The leafless mahoe is an interesting oddity, it grows as a bundle of interlaced soft grey twigs, and would be great in a big planter.
25 rare plants were given away during the day. They were swapped for such weeds as Himalayan honeysuckle, Darwinís barberry, chocolate vine, buddleia, and holly.
Caption for photo: DOC ranger Sandra Wotherspoon holds a clump of chocolate vine (Akebia quinata) which Murchison local Jean Hayward has swapped for a plant of leafless mahoe (Melicytus flexuosus)
A good place to look for more information on NZ native plants is the NZ Plant Conservation Network website, www.nzpcn.org.nz