Weedbusting has been an integral part of the MECG’s commitment to the restoration of streams running through Murchison township. The group has worked with DOC, TDC, Landcare and landowners since 2003 to fence stock out of streams on private and public land (the Murchison Domain), and plant the riparian strips in native vegetation. Before the buffers are planted, environmental weeds are destroyed via mechanical and chemical means, and follow-up work has been required in some planted areas to remove regrowth. In every case the only required land-based weedbusting has been to remove blackberry and buddleia (B. davidii).

As all the newly fenced areas were previously grazed, there has not been much in the way of land-based weeds but the expectation is that as birds begin to use the native vegetation in the new riparian strips, weeds such as hawthorn, barberry, and ivy will invade. The newly planted areas are regularly checked as part of ongoing plant maintenance but apart from a few blackberry plants the only weeding of terrestrial plants has been regular removal of rank pasture grasses from around new plantings.

Aquatic weeds have required much more ongoing attention. All of Murchison’s small streams suffer from severe siltation and where stock don’t have access, there are such growths of aquatic weeds as to completely obscure the water surface in most situations. They are naturally slow-flowing streams, made even slower by siltation and weed growth until a flood event when there are sometimes problems with the stream blocking with weed and flooding surrounding land.

With the removal of stock the siltation of streams has partially eased as there are no animals breaking the stream banks, but then at least twice each summer the fenced-off sections of stream require clearing of water weeds. This is done mechanically by a MECG member in a pair of trout waders, and a custom-made weed-rake. The weeds, mostly watercress and monkey musk, are raked out of the water and left on dry land to die. If the riparian strip has already been planted then the weeds are used as a mulch around the new plants.

Nominated by: Sandra Wotherspoon, Ranger, biodiversity, DOC Nelson Lakes