Nelson Nature Fix
22 November 2018
Welcome to the Nelson Nature Fix - a regular snippet about Nelson's natural environment, and what we can do to look after it. If you know anyone who you think might enjoy getting a regular nature fix, please pass this on and encourage them to sign up. You can read back issues here.
The Dun Mountain mineral belt forms a distinctive, unique landscape
Mineral Belt Weeds
Pest plants are a perpetual issue for many of us in Nelson, especially at this time of year when vine weeds like old man's beard and banana passionfruit take full advantage of the conditions to sprawl at a seemingly unnatural pace. The impacts of these are close to home and easy to see.
The hills behind Nelson are not as susceptible to weedy vine invaders, but the specialist environment of the Dun Mountain Mineral Belt means that invasion by weed species adapted to the conditions there can devastate a whole ecosystem.
Nelson Nature is targeting the biggest threats - gorse, Spanish heath and wilding conifers - to control existing plants and prevent reinfestation.
Spanish heath and gorse
Spanish heath is one of the weeds threatening the Dun Mountain ecosystem
A programme is underway to remove Spanish heath and gorse from the remote areas in Nelson's backcountry.
The environment is harsh around the Dun Mountain, where the lack of ground cover and shelter means hot, dry conditions in the summer. Low nutrient soils and levels of magnesium, nickel and chromium that would be toxic to most plants have resulted in a unique community of mineral belt species adapted specifically to this environment.
Spanish heath and gorse are not usually a major threat to native ecosystems as they only grow 2-3m high and are readily outcompeted by taller trees and shrubs. However, they specialize in poor soils and high light conditions, making them strongly competitive in the delicate Dun Mountain ecosystem where there is nothing to shade them out. Without control, they would slowly but surely take over the habitat.
It is not easy work but it is vitally important if we are to preserve this rare and amazing ecosystem.
The spread of wilding conifers in the Dun Mountain area has been controlled by Council contractors
Wilding conifers originate in plantation forests and are spread by windblown seed being transported long distances to colonize high light – low fertility environments, like our mineral belt.
Nelson Nature contractors have made huge progress removing wilding conifers from the Roding and Maitai water reserves. Almost all the mature seeding trees have now been controlled and we are progressing to a maintenance phase where young trees are removed before they can set seed.
Conifer spread is a huge issue nationally, especially in the high country. Find out more about controlling wilding conifers and preventing their spread here
Are you a landowner with an interest in forestry for soil protection? Council's Healthy Streams programme is working with the NZ Landcare Trust to present a community seminar on Trees in Productive Landscapes, at Wakapuaka Hall on the evening of 29 November. Find out more here